India Nuclear News And Discussion

[JwalaMukhi]

http://villageofjoy.com/chernobyl-today ... -pictures/
http://www.nuclearflower.com/april/ghosts.html

[Theo_Fidel]

We should be careful with a technology that we can not fully control. Esp. when the consequences can be so large.

[arnab]

http://villageofjoy.com/chernobyl-today ... -pictures/
http://www.nuclearflower.com/april/ghosts.html

Very moving. But here is what we get with the alternative

The creation of reservoirs for Narmada Sagar Project (NSP) and Sardar Sarovar Project (SSP) would result in
the submergence of 91,348 ha. and 39,134 ha. of land respectively.

Villages coming under total submergence: 89

Total Population affected: 1,29,396

http://www.ielrc.org/content/c8601.pdf

[JwalaMukhi]

^ One will be a slow motion boiling of water for the frogs caught in the container. The other is instantaneous grim picture. The slow motion does provide a semblance (only a semblance) of control to allow voluntary evacuation. The instantaneous scenario is involuntary drafting of random individuals.
In the case of flood etc., it is deemed to be an act of divine, and people move on. In the other case, it will be deemed as an act of playing divine by man and tough for humanity to move on. There will be no resolution, to the question of was/is it wise to play god? in the instantaneous scenario.

[arnab]

^ One will be a slow motion boiling of water for the frogs caught in the container. The other is instantaneous grim picture. The slow motion does provides a semblance (only a semblance) of control to allow voluntary evacuation. The instantaneous scenario is involuntary drafting of random individuals.
In the case of flood etc., it is deemed to an act of divine, and people move on. In the other case, it will be deemed as an act of playing divine by man and tough for humanity to move on. There will be no resolution, to the question of was/is it wise to play god? in the instantaneous scenario.

Sir, both are man made - the submergence of the villages due to Narmada and Sardar Sarovar is due to the catchment area of the man-made decision to build a hydro-electric power station. At least in the case of Chernobyl - the exclusion zone is slowly being reduced and may eventually give way for re-settlement. In the case of the dam - the loss of land is permanent.

[JwalaMukhi]

Advance warning and the ability of people to see the danger plays a major role in perception. Things that are not seen evokes acute sense in loss of control.
Man made scenario extended over a period of time looses the punch and hence boiling water for the frog analogy.
Man made scenario happening in a relatively short period of time invokes revulsion.

[arnab]

Advance warning and the ability of people to see the danger plays a major role in perception. Things that are not seen evokes acute sense in loss of control.

True which is why the UN committee studying the Chernobyl disaster over the last 30 years concluded that the most significant issues from the nuke disaster was on mental health rather than cancer / contamination and such.

But as you said - these are perceptions. Reality is unfortunately rather different and the longer we continue to ignore the reality of the impact of coal / fossil fuels, the ruder the awakening we will have.

[somnath]

^^Jwalamukhi-ji,

The issue of black swan disasters is pertinent enough to be pitted against the "nuke lobby" without taking recourse to non-sequitors like "advance warning"...What would be the advnace warning of an erthquake of 9 on the Richter? Something like that with an epicentre under the Tehri dam - what impact will it have on the dam and the resulting flash floods?

Forget an earthquake...There are flash floods in various parts of the country almost every year...And if you ask Vandana Shiva, bless her, she will tell you that every single one of them was a result of dams....

Lets not be blase about these things - accidents are acidents, black swans...And the impact from them can never be calculated with any great degree of confidence..Who would have thought that an oil spill will cost 30 billion dollars before 2010?

[GuruPrabhu]

As all technologies fall by the wayside, perhaps my comment regarding returning to Vedic times is not so OT anymore, eh?

My next great idea: GOI should take out $1,000,000,000,000 liability insurance against its Bobooze having a collective brain freeze. The public needs to be protected from such an event.

The insurance against the Babooze having a "great idea" should be pegged even higher.

[AKalam]

I have been listening to KPFK Los Angeles also known as Pacifica Radio. While driving to work and back, I listen to this gentlemen, Ian Masters and his interviews with assorted industry experts:

http://ianmasters.com/content/mar-31-nu ... alism-over

The feeling I got on the issue of New Cooler power is that:

- there is a consensus among industry insiders that Fukushima has become the death knell for New Cooler renaissance
- Germany will be phasing out New Cooler power altogether, US will probably scrap the govt. loan and may not build any future reactors, other developed countries may follow
- liability is the biggest issue as no private insurance company would touch any New Cooler plant, as there was a study which concluded that a China syndrome for a particular plant would cost 300 billion in damage in 1980 USD or something to that effect, which is more than several trillion in todays dollars, and it probably matches well with the Fukushima incident
- only reason the New Cooler plants still operate is because they are insured by the US tax payers

Essentially it is an unsafe and dirty method for producing power, the future effect of all aspects of which is still not well understood. No other power generation method has as much risk or downside for people living in surrounding areas as well as affected areas far from plant locations, even in other countries.

Global warming cannot be an excuse for promoting Nuclear power. Now while this industry is loosing market in countries where people are aware of the dangers, is it possible that this dirty and dangerous industry will be pushed for poorer countries like China, India and others who have huge energy needs. I guess people are more expendable in these countries and land becoming unusable is not much of a concern?

IMHO it is better to err on the side of caution. Technology is a double edged sword, we need to be careful about their use, specially the ones we still don't understand very well.

If we sit out a few more decades, there will be plenty of technology that may become available, the down sides are that development and growth may slow down a bit, the question is by how much. I think that is a better outcome than making mistakes which can be very costly in the long run.

But there is another factor, which is without a home grown industry, one cannot have New Cooler MAD ness, I suppose, so one probably needs it for other reasons than power generation as well.

Just wanted to share the general feeling about this issue among talking heads in liberal radio in the US.

[Amber G.]

^^^ Meanwhile the industry leaders who met in Chicago at the first major conference post Fukushima has this to say:
Prepare for a new nuclear industry

The nuclear power industry will change in the years after the Fukushima accident but the need for the technology will not, said industry leaders today in Chicago at the first major conference since the crisis began.

Opening statements at the World Nuclear Fuel Cycle 2011 conference included grave warnings of the hard road ahead for nuclear power. "We must admit that we represent a technology that has frightened a great many people," said Richard Myers, vice president of policy development at the US trade group the Nuclear Energy Institute. "But the industry can explain the unfounded nature of this fear, and provide the data to prove it is so."

Immediate political and regulatory responses to the accident have varied and it still remains to be seen how safety requirements may be revised. Despite this uncertainty, World Nuclear Association director general John Ritch noted: "In the years preceding Fukushima, most major nations in the world reviewed their energy and environment policies and, with few exceptions, came inexorably to the same conclusion: that, for reasons of energy independence and environmental responsibility, nuclear power must play a central role in their energy strategies for the 21st Century."

Most nations have announced the intention to review safety arrangements on the basis of the facts of the Fukushima accident as they become known. For some this means new build projects could be delayed for several months and engineering costs could rise.

Only one country seems to have embarked on a route truly damaging to its nuclear sector: Germany. One delegate spoke of personal doubts that the eight units shut down by Chancellor Angela Merkel will ever restart while politicians compete to be seen as the most green.

On a technical level the industry must meet safety challenges on a new plateau: to survive combinations of extraordinary events beyond their design basis, including natural disasters, terrorist attack and as-yet unimagined disasters and difficulties in their locality. The limits of legally required preparation and response are to be rewritten.

Furthermore, regulators will focus on the ability of a single company to tackle a nuclear emergency at a time when the infrastructure of its nation has been compromised. Commercial cooperation with government will be one aspect of that. Operation during extended plant blackouts and under difficult radiological conditions will be studied and it is sure that emergency power arrangements are to be hardened in many countries.

Separate from the considerations of governments, industry mechanisms exist to address the challenges exist in the form of the US Institute of Nuclear Power Operations and its global sister organisation the World Association of Nuclear Operators. These are already offering top technical assistance to Tokyo Electric Power Company based on the combined operational experience of the global industry.

Ritch underlined the fortification these institutions will now undergo and that they must be combined with clear international messaging to the general public worldwide: "In the aftermath of Fukushima we must meet the further and compelling challenge of explaining just what happened at the Daiichi plant and presenting, in accurate and persuasive terms, the measures by which the industry is acting on a broad front to fortify all needed barriers against the recurrence of any such accident, anywhere."

[Sanku]

http://www.swissinfo.ch/eng/politics/De ... witzerland

Decommissioning nuclear plants comes at a price

Dismantling is an extremely complex and lengthy procedure, and may produce nasty surprises, and thus raise costs.

For example, Swiss television revealed in 2006 that workers dismantling the experimental Diorit reactor in Würenlingen in northern Switzerland had unexpectedly found asbestos had been used in the construction, exposing them to further risk.

And if the plants are closed prematurely, there will be no more money feeding the funds.

Under the law on nuclear energy, the operators are responsible for making up any shortfall. But experts doubt their capital ratio would be sufficient to cover it.

[Theo_Fidel]

We build dams to feed ourselves and for the drinking water. It is indeed a brutal choice but with a Billion to feed we swallow the pain and do it. The power we get is merely added benefit.

Nuclear is different. It is an optional power source. We are seduced by its capacity and short term cheapness. It long term risks and consequences should sober us.

Also Uranium is not a inexhaustible resource. Right now there is a glut due to Russian and US decommissioning of weapons that are providing the equivalent of about 15,000 tons of fuels per year. Actual Uranium production is running below consumption. Just to give some numbers, Uranium demand is expected to hit 80,000 tonnes per year by 2015. This is well before the Chinese and India finishes their build out. Australia with 1/3 the worlds Uranium deposits has 350,000 tonnes of reserves. At current+future consumption all present deposits will be exhausted by 2035. At which point India, with next to no reserves, will have to run around begging for Uranium. If we build out to 40,000 MW of power we will need roughly 10,000 tonnes annually. China plans 5 to 10 times as much. We now produce about 600 tonnes annually after a heroic effort. This is enough for about 3,000 MW/hr, that's it. Its not going to get much better.

Of course increasingly desperate measures are possible. We could turn to fast breeder technology to produce Plutonium and then we would have a much longer supply. Of course this is the Molten Sodium (not salt), and fuel reprocessing technology. Fantastically expensive and generates tonnes of contaminated waste. All of this dramatically increases risk. Also we would have to build it right now to be ready in 20 years time. We could resort to more unconventional sources that get progressively costlier and less reliable.

By contrast utility scale Solar Thermal and offshore/onshore wind are looking very promising. A utility scale Solar Thermal plant of levelized 100 MW would cost roughly Rs1,000 crore to Rs 1,500 crore, bit cheaper than EU experience. It would occupy 1.5 sqkm. It would use molten salt (not Sodium), Calcium Nitrate or Sodium Nitrate heat storage to even out the load. The area from Koodankulam to Nanguneri is extra ordinarily dry and experiences 330 days of sun light in a year. 50 of these units would occupy less than 10% of the land area and would provide a very levelized 5000 MW/hour of power, remember the molten salt storage.

All this is admittedly at a relatively high cost of Rs50,000 to Rs 75,000 crore. If we split the difference say $12 Billion for the lot. Yes, Kudankulam is cheaper up front but not by much and see the long term costs coming down the road.

[amit]

The issue of black swan disasters is pertinent enough to be pitted against the "nuke lobby" without taking recourse to non-sequitors like "advance warning"...What would be the advnace warning of an erthquake of 9 on the Richter? Something like that with an epicentre under the Tehri dam - what impact will it have on the dam and the resulting flash floods?

Even though the very thought of this gruesome but this is an apt comparison with what happened at Fukushima on that fateful day on March 11.

A Black Swan like a 9.0 scale earthquake will shatter Tehri Dam and how many millions will die downstream? Tehri is in an earthquake prone zone. In fact serious studies have been conducted. There's a paper by A Sengupta, Estimation of Permanent Deformations of Tehri Dam Due to 7.0 and 8.5 Magnitude Earthquakes, at the Amercian Society of Civil Engineers website. Unfortunately you have to pay to access the full report. However, the synopses does say this:

The objective of this paper is to find the permanent deformations of Tehri dam due to an earthquake of magnitude 8.5, the occurrence of which has a high probability in the region, and for an earthquake of magnitude 7.0, for which the dam has been currently designed. Instead of finite element analysis, five different empirical methods, Makdisi and Seed’s method, Newmark’s double integration method, Jansen’s method, Swaisgood’s method and Bureau’s method have been utilized and their results compared to get a range of values within which the permanent deformation of the dam is estimated to lie. The present analyses show that the predicted deformations due to an earthquake of magnitude 7.0 do not compromise the safety of the dam. However, the deformations predicted for an earthquake of magnitude 8.5 are quite high. The maximum deformations are predicted by Makdisi and Seed’s method while the minimum deformations are computed by Jansen’s method.

It's not as if people are not worried. Here's an old report from 2004 which quotes Sunder Lal Bahuguna.

Environmentalists in Tehri, home to the world’s fourth biggest dam project, fear for the safety of millions of residents saying that the highly seismic region could get active again.

After the Tsunamis killed thousands in Asia, people living near the Tehri Dam are worried about their lives, as the region is an earthquake prone region. Scientists fear the 260-metre high Tehri Dam is coming up in an earthquake-prone area and can endanger the lives of millions if damaged. Landslides occur frequently in this region.

Environmentalists, therefore, believe that the mountains will not be able to bear such a huge structure. “This is an indication for us because this is earthquake prone zone. People say this will not affect the dam but I doubt as these hills are very weak and these will fall into the dam,” said Sunder Lal Bahuguna, an eminent environmentalist.

Local people have been opposing the dam. Many scientists and environmentalists have pointed out the grave risks involved in building this dam in a highly earthquake-prone zone. But authorities dismiss these allegations of risk saying the project is really going to be beneficial for the people. “The inspection of the dam has been done. Our dam is safe there is no question about it. Dam is completed. Now we have to take benefits from this dam,” said S.C Sharma, director of the Tehri dam.

I would point to the colored portion above. It's a risk-cost-benefit analysis. Can any scientist say that there's never going to be a earthquake higher than 8.0 on the Richter scale over the lifespan of the dam? Or for the matter other mega dams that we are building or may build in the future? Do note that hydel is clean energy.

So what do we do, stop building dams or try to build ones that have as many safety features as possible built into them?

Why is there a problem when the same logic/yardstick is applied to nuclear power plants? Do not that almost a month after Fukushima there's still been no death directly related to the nuclear accident. Could we have said the same after a month if that 9.0 hit Tehri?

[arnab]

At current+future consumption all present deposits will be exhausted by 2035. At which point India, with next to no reserves, will have to run around begging for Uranium.

Is this true? The NEI says the following:

Uranium is one of the world’s most abundant metals. The Organization for Economic Cooperation and Development (OECD) and the International Atomic Energy Agency (IAEA) in 2008 jointly produced a report on uranium resources. [1] The report states that uranium resources are adequate to meet nuclear energy needs for at least the next 100 years at present consumption levels. More efficient fast reactors could extend that period to more than 2,500 years.

http://www.nei.org/resourcesandstats/do ... yadequate/

I'm all for exploring other sources of clean energy - solar / wind etc; but as things stand currently technology wise - there isn't any other alternative for sustained baseload elctricity.

[amit]

We build dams to feed ourselves and for the drinking water. It is indeed a brutal choice but with a Billion to feed we swallow the pain and do it. The power we get is merely added benefit.

Nuclear is different. It is an optional power source. We are seduced by its capacity and short term cheapness. It long term risks and consequences should sober us.

Sorry to say this boss, I respect you a lot but you're totally way off on this. Nuclear is not an optional power source.

And dams may be built for drinking water on the Deccan Plateau but dams like Tehri are not built for drinking water, they are for power generation.

Besides if its a risk analysis of nuclear vs big dam hydel, we should look at loss in human terms, na? Let's say if we are comparing a hypothetical nuclear accident in India with a dam burst, can you tell in which there's likely to be more human lives lost at first impact of the accident or even subsequently?

Fearing the nuclear beast is good but irrational fear is bad.

Also Uranium is not a inexhaustible resource. Right now there is a glut due to Russian and US decommissioning of weapons that are providing the equivalent of about 15,000 tons of fuels per year.

Boss you seem to have lost the entire purpose of our three stage program. The idea is to move to thorium and for that as of now we need uranium from abroad and the cheaper it is the better for us. If our nuclear roadmap goes according to plan then we're going to kick our uranium fix habit. And I suspect the entire global nuclear industry will do as well before uranium runs out, just as there's going to alternative to oil as fuel before it runs out.

By contrast utility scale Solar Thermal and offshore/onshore wind are looking very promising. A utility scale Solar Thermal plant of levelized 100 MW would cost roughly Rs1,000 crore to Rs 1,500 crore, bit cheaper than EU experience. It would occupy 1.5 sqkm.

Sorry boss but but your figures are totally out of whack. The per unit cost of solar is higher.

See this



More information is available here

There's table from 2008 which shows that nuclear is very much competitive and the calculation takes into account decommissioning cost.

[amit]

Just to put it on record and dispel the myths about solar power, here's a para from the link I posted above:

Hydroelectric is the most cost effective at $0.03 per kWh. Hydroelectric production is naturally limited by the number of feasible geographic locations and the huge environmental infringement caused by the construction of a dam. Nuclear and coal are tied at $0.04 per kWh. This comes as a bit of a surprise because coal is typically regarded as the cheapest form of energy production. Another surprise is that wind power ($0.08 per kWh) came in slightly cheaper than natural gas ($0.10 per kWh). Solar power was by far the most expensive at $0.22 per kWh—and that only represents construction costs because I could not find reliable data on production costs. Also, there is a higher degree of uncertainty in cost with wind and solar energy due to poor and varying data regarding the useful life of the facilities and their capacity factors. For this analysis the average of the data points are used in the calculations.

Note that this study found coal and nuclear to be tied despite factoring in decommissioning costs for nuclear power plants.

Also note that solar power is heavily subsidized in Euroland and Amir Khan as it is seen to be darling of the clean tech lobby which of course does not take into account the pollution generated in producing the solar panels.

[somnath]

Also Uranium is not a inexhaustible resource. Right now there is a glut due to Russian and US decommissioning of weapons that are providing the equivalent of about 15,000 tons of fuels per year. Actual Uranium production is running below consumption. Just to give some numbers, Uranium demand is expected to hit 80,000 tonnes per year by 2015

Theo-ji, this is just not true..The dates for "peak Uranium" have been puched back consistently..The reason is simple, at a certain level of oil prices, all "alterantives" start looking attractive..But nuke looks attractive at much lower levels of oil prices..Ergo, more intensive efforts on Uranium mining gets implemented..At 120 dollars per barrel of oil, uranium mining investments are much more forthcoming...

By contrast utility scale Solar Thermal and offshore/onshore wind are looking very promising. A utility scale Solar Thermal plant of levelized 100 MW would cost roughly Rs1,000 crore to Rs 1,500 crore, bit cheaper than EU experience. It would occupy 1.5 sqkm. It would use molten salt (not Sodium), Calcium Nitrate or Sodium Nitrate heat storage to even out the load. The area from Koodankulam to Nanguneri is extra ordinarily dry and experiences 330 days of sun light in a year. 50 of these units would occupy less than 10% of the land area and would provide a very levelized 5000 MW/hour of power, remember the molten salt storage.

not sure what is the land area between Kudunkulum and Nanguneri, but an estimate of the "land area intensity" of solar is here..
http://www.newscientist.com/article/dn1 ... ature.html

Solar power is much more efficient than biofuel in terms of the area of land used, but it would still require 150 square kilometres of photovoltaic cells to match the energy production of the 1000 MW nuclear plant

We find it difficult to acquire even a few hundred acres! How do we acquire 1500 sq kms (!!) of land for a 10,000 MW solar capacity!

The other big question is, even if theoretically you did the above, can this 10k MW capacity act as base load power for the region? The answer is, with today's tech, no...

We build dams to feed ourselves and for the drinking water. It is indeed a brutal choice but with a Billion to feed we swallow the pain and do it. The power we get is merely added benefit

Sorry, it doesnt happen that way...GM crops are also (according to some) hugely critical to feed the world...A lot of people are not "biting" (no pun intended!) it still, incl our very own Jairam Ramesh..

On the cost of nuke power, total costs, there are lots of estimates - I see Amit's posted one, I had posted another sometme back...Including the estimates in India by Prof Ramprasad Sengupta, which show that nuke power (at India's efficiency elvels, much lower than the rest of the world) is compettiive against ALL other sources..

[Theo_Fidel]

I don't understand how you can estimate total nuclear cost without going through the entire decommissioning process. Let me point out that every decommissioned facility in the US transferred its contaminated waste and waste fuel to another facility or are continuing to maintain the cooling pools. Costs continue to pile up yet we pretend that the station has closed. Also every estimate shows that the safety requirements have caused the cost of new plants to quadruple or more in the US. After Fukushima you can bet it will increase even more. I have posted exactly what it is costing to decommission one single item now, not 10 years ago.

Solar thermal is cheaper than Photo-electric and getting cheaper all the time. Those costs are based on the new Spanish plants and is why I said the technology has really come on recently. The 5000 MW would be similar to base load as the salt smooths the spikes. That is how the Spanish plants operate. In any case the Solar Thermal production almost perfectly match the grid demand spike and has proven very useful in Spain. Yes, land acquisition would be tough but keep in mind Kudankulam has acquired an area of 5 km in radius as part of its sterilization zone. About 25 sqkm or 5000 or so acres. 50 solar thermal plants of 1.5 sqkm would only occupy 75 sqkm. And if you have visited the area south of Nanguneri you would understand why there will be no problems acquiring this wasteland. Why Kudankulam came here in the first place. Keep in mind new Nuclear plants in the US now have power costs of 12-14 cents. Still cheap but no where near what they claim. And this is after essentially free insurance cost.

As far as that 4.4 million ton number, it is a in place in the ground number, the actual recovery rate would be much less. It also includes proposed mines and reserves in national forests where clearance would be problematic to say the least. This is because no new Uranium mine will be open pit or underground tunnel type due to pollution regulations. They are all in situ liquid leaching techniques which have far lower recovery rates. The weapons & stockpile releases are going to drop to zero over the next 10 years. At which point demand is going to be 100,000 tonnes while present production is 40,000 tonnes. So over the next 10 years a 250% increase is needed. We should not listen so much to the nuclear industry. Also keep in mind when they do these estimates India's requirements are not figured in. Most of the Uranium is in the Western countries and meant for their use.

WRT reprocessing, Kalpakkam has a Uranium reprocessing capacity of 100 tonnes per annum. A Thorium reprocessing facility does not exist yet. A fast breeder cycle will require several reprocessing's. Each step a massive cost burden.

As far as Thorium, only the second stage is being built now. There is no guarantee this will work. The NPCL has admitted that the Third stage will not be ready till 2030 or so. So far even the second stage is not burning Thorium.The past Breeder reactors have not been as efficient as originally thought. We will see how efficient this new on is in 'converting' the fuel. To tell you how uncertain the scientists themselves are, the 500MW breeder in Kalpakkam has been engineered to use U-238 and not Thorium so they can prove the facility first. Thorium has always proven tough to work with, even in the CANDU reactors which have also been disappointing using Thorium hence the shift to the three step process.

[somnath]

Theo-ji,

There are lots of studies on life - cycle costs of various sources of power...Here is one..

http://www.worldenergy.org/documents/co ... rs/482.pdf

And this is without taking into account carbon credits that nuke power (and other alternative sources) would be getting, which would only skew nukes further more in the favourable domain..

[amit]

I don't understand how you can estimate total nuclear cost without going through the entire decommissioning process. Let me point out that every decommissioned facility in the US transferred its contaminated waste and waste fuel to another facility or are continuing to maintain the cooling pools. Costs continue to pile up yet we pretend that the station has closed. Also every estimate shows that the safety requirements have caused the cost of new plants to quadruple or more in the US. After Fukushima you can bet it will increase even more. I have posted exactly what it is costing to decommission one single item now, not 10 years ago.

Theo,

The study I referred to clearly says nuclear pricing took into account decommissioning costs. If you don't agree with the estimates please provide a source to back that claim.

That is how the Spanish plants operate. In any case the Solar Thermal production almost perfectly match the grid demand spike and has proven very useful in Spain. Yes, land acquisition would be tough but keep in mind Kudankulam has acquired an area of 5 km in radius as part of its sterilization zone. About 25 sqkm or 5000 or so acres. 50 solar thermal plants of 1.5 sqkm would only occupy 75 sqkm. And if you have visited the area south of Nanguneri you would understand why there will be no problems acquiring this wasteland. Why Kudankulam came here in the first place. Keep in mind new Nuclear plants in the US now have power costs of 12-14 cents. Still cheap but no where near what they claim. And this is after essentially free insurance cost.

Sigh! You bring up the example of the Spanish solar power generation!

Here's a random link about the subsidies that underwrite the Spanish solar energy programme.

Solar investors were lured by a 2007 law passed by the government of Prime Minister Jose Luis Rodriguez Zapatero that guaranteed producers a so-called solar tariff of as much as 44 cents per kilowatt-hour for their electricity for 25 years — more than 10 times the 2007 average wholesale price of about 4 cents per kilowatt-hour paid to mainstream energy suppliers. Now more than 50,000 other Spanish solar entrepreneurs face financial disaster as the policy makers contemplate cutting the price guarantees that attracted their investment in the first place.

Spain stands as a lesson to other aspiring green-energy nations, including China and the U.S., by showing how difficult it is to build an alternative energy industry even with billions of euros in subsidies, says Ramon de la Sota, a private investor in Spanish photovoltaic panels and a former General Electric Co. executive. “The government totally overshot with the tariff,” de la Sota says. “Now they have a huge bill to pay — but where’s the technology, where’s the know-how, where’s the value?”

Read the original report here

So you are OK with giving massive subsidies to solar energy generation in India? And I suppose that doesn't affect the per unit cost of power?

[amit]

Talking about uranium availability, this MIT study says on page 12:

This reinforces the observation in the 2003 MIT study that “We believe that the
world-wide supply of uranium ore is sufficient to fuel the deployment of 1000
reactors over the next half century.”

Note there's 440 nuclear power plants operating today and about 60 are being constructed around the world.

[abhishek_sharma]

Nuclear power: Chernobyl and the future: when the price is right: Jim Giles

Once touted as too cheap to meter, nuclear power has become too costly to build. But the economics may be shifting, finds Jim Giles.

Nature 440, 984-986 (20 April 2006) | doi:10.1038/440984a; Published online 19 April 2006

http://www.nature.com/nature/journal/v4 ... 0984a.html

On the east coast of Britain sits one of the most convincing arguments for ending the age of nuclear power. The Sizewell B reactor is not dangerous: since it opened in 1995 it has never been the subject of a serious security scare. Nor is it unreliable. Quite the reverse: at almost 1,200 megawatts, it is Britain's most powerful single nuclear reactor and is responsible for supplying 3% of the country's electricity needs. But Sizewell B is expensive. So expensive that no private investor would ever touch such a project.

For nuclear experts, the story of Sizewell B is a familiar one. After the longest public inquiry into a construction project that Britain had ever seen, work began in 1987. It took eight years to come online. The budget was revised upwards three times over that period, eventually coming in at more than a third over the £2 billion (US$3.3 billion) quoted in 1987. When the British government reviewed the project in 2002, it estimated that, when the costs of financing, building, running and decommissioning Sizewell B were fully accounted for, the average cost of every kilowatt hour (kWh) of electricity produced over the plant's 40-year life would be six pence — two to three times more expensive than power generated by modern gas-fired stations.

Running down

Nuclear power stations account for a fifth of the electricity generated in the United States and a third of that generated in Europe. But they are getting old. Since the 1979 accident at the Three Mile Island plant in Pennsylvania, orders for new reactors in the United States and Europe have reduced to a trickle. Decisions on how to replace the existing plants need to be made within the next ten years. And although renewable sources such as wind are looking increasingly attractive, large central power stations can only realistically be powered by nuclear fission, coal or gas.

Almost all recent studies of nuclear energy have found that gas- or coal-fired replacements would be much cheaper. Given this underlying lack of competitiveness, why bother taking on board the associated risks of terrorism and weapons proliferation that come with the technology, not to mention the displeasure of many citizens? The answer is that when the downsides of fossil fuels — including, but not limited to, their carbon dioxide production — are totted up, nuclear power begins to look more attractive. Some economists are even starting to place bets on a nuclear renaissance.

The current economic picture is persuasively summed up in the 2003 nuclear-economics report from the Massachusetts Institute of Technology (MIT) [1]. After considering the cost of building the plant, buying fuel and operating the reactor, and finally disposing of the waste and decommissioning the facility, the MIT team placed the cost of nuclear electricity at 6.7¢ per kWh. Gas came in at 3.8–5.6¢ per kWh, depending on wholesale gas price, with coal somewhere in the middle of that range. A 2005 report by the UK Royal Academy of Engineering [2] put nuclear costs on a par with coal and gas, but used some unreasonably favourable economic assumptions.

Much of nuclear power's expense comes from construction costs, and the debts that must be incurred to pay them (see chart). A 1,000-megawatt gas-fired plant could, in favourable circumstances, be built in a year or so for $400 million, but a 1,000-megawatt nuclear reactor is likely to take five years to build and to cost between $1.5 billion and $2 billion, depending in part on where it is sited. The long construction time drives the price up by increasing the amount of interest that must be paid on the money borrowed for the project.




And the length of the gestation isn't even predictable; it depends in part on "how slick the lawyers are", notes Donald Jones, an energy economist at RCF Economic and Financial Consulting in Chicago, Illinois. If opponents of nuclear power raise legal challenges, costs mount up quickly. "Halting construction for two years in the middle adds 15% to the final cost of electricity," Jones says. In 2005, hoping to encourage the industry by offsetting this risk, the US Energy Policy Act offered energy companies $500 million of coverage for losses due to construction delays. Yet US investors remain wary of nuclear projects.

Balancing act

Once a nuclear plant is running, operational costs are relatively low. But there are two important exceptions: storage of radioactive waste and, at the end of the reactor's life, decommissioning costs. In Britain, estimates of the funds required to clean up the country's 20 civil nuclear sites have frequently been revised upwards. Just last month, for example, officials increased the total predicted bill from £56 billion to £70 billion. Some schemes to deal with waste costs are in place — the United States has a levy on nuclear electricity that will fund the country's planned waste-storage facility at Yucca Mountain in Nevada (see page 987). But uncertainty about these costs continues to worry investors.

The economic picture hasn't stopped all construction of nuclear power plants. India, China and Russia are building a handful of reactors, for example, but all are government-funded projects. It is in Europe and the United States, with their largely deregulated energy markets, that the economic arguments have bitten deepest. Finland is the only Western nation to have a new nuclear reactor under construction, but its Olkiluoto station, due for completion in 2009, makes economic sense only because of an unusual funding mechanism: local industries are paying for the plant in return for a contract from the operator that guarantees them low-cost electricity. This is not a model that can easily be exported.

France may also decide to order a new reactor, possibly this year. But again the situation is different from that in most countries. France's experience with the technology means that investors will loan money for projects at a cheaper rate than elsewhere. A French 2003 study, for example, put the price of future nuclear electricity at 3.5¢ per kWh — the lowest figure in any of the recent reviews, with the exception of estimates for Olkiluoto.

When cost comparisons are extended beyond current prices and business practice, however, nuclear looks like a feasible option even beyond the borders of France. For a start, although the nuclear industry faces some unique challenges, the finances of its two major competitors are also looking a little troubled. Take gas: wholesale prices have increased fourfold over the past six years. That pushes the price of electricity from gas-fired stations to around 15% below nuclear.

That gap will shrink further if industry forecasts about the efficiency of modern plants are accurate. Nuclear lobby groups claim new plants could probably be built in four years, not five. Independent experts are aware that the industry has a record of what is euphemistically known as 'appraisal optimism'. But the MIT study, which worked with costs larger than those the industry usually uses, acknowledges that improvements are "plausible". If this were so, the cost of nuclear electricity would come down to 4.2¢ per kWh, making it competitive with gas and coal.

Fair exchange

Factor in the cost of greenhouse-gas emissions, and things look even better for nuclear. In Europe, where emissions from industry are already regulated and traded on a carbon market, prices are currently around $30 per tonne of carbon dioxide. At that price, says Paul Joskow, an economist and participant in the MIT study, nuclear is competitive with coal and gas, at least if the price of the latter remains high. This remains the case even when the cost of the carbon burned while the plants are built and their fuel mined and processed is taken into account.

This broader analysis, which the nuclear industry is understandably keen to promote, boosts its standing. But where should the process of extending the cost comparisons end? Environmental groups say that going as far as carbon prices and no further means taking into account all the costs of other generators while leaving out costs specific to nuclear, such as lowering the barriers to nuclear proliferation. Assessing that argument takes the calculations on to less certain ground, although a smattering of studies have attempted to quantify some of the issues. Inasmuch as anything can be said for sure, however, it seems that the more inclusive approach may improve the case for nuclear.

Take disaster liability. In Britain, the amount that reactor owners have to pay out in the event of an accident is limited to £140 million ($250 million). US industry contributes to a pool of money that ensures that up to $10 billion is available. Neither figure would be anything like sufficient should a disaster on the scale of Chernobyl occur (see page 982). The extra cost would have to be picked up by the taxpayer, so "in essence this is government-subsidized insurance", says Matthew Bunn, a nuclear expert at Harvard University. If nuclear were forced to insure itself on the open market, it would find it impossible.

Government crutch?

But how big a subsidy this actually is remains unclear, because the real risk of catastrophic accidents is unknown. Estimates can be generated by looking at the frequency of previous accidents and how the associated costs compare with events for which the insurance industry is prepared to provide cover. The MIT study suggests that the subsidy amounts to just $3 million per plant per year — a tiny figure when reactors produce $500 million of electricity annually. "In terms of the impact on the cost of electricity it's lost in the noise," says Richard Lester, an author on the MIT study.

What's more, nuclear is not the only industry that benefits from subsidized insurance. A major explosion at a depot handling liquid natural gas could produce a bill well beyond the scope of the owner's cover. So would the wall of water let loose from a hydroelectric dam destroyed by an earthquake. "There is an implicit assumption that the government would step in," says Lester. "Everything has an insurance limit."

Some other costs are simply unquantifiable. The European Union's ExternE study [3], which has been running since 1991, provides perhaps the fullest accounting of what economists call 'externalities' — costs that the people directly involved don't end up paying. ExterneE's audit assigns nuclear extra environmental costs of 0.2–0.8¢ per kWh, mostly derived from air pollution attendant on the plants' construction, mining and transport of fuel, and decommissioning. The figures for fossil fuels, which include damage to the climate as well as air quality, are much higher — up to 18¢ per kWh for coal. Yet even when ExternE's comprehensive analysis is considered, some things are still unaccounted for. "We can't include terrorism issues," says Anil Markandya, an economist at the University of Bath who works on ExternE. "We don't have a handle on how to quantify that." There is also the cost that would be incurred were an unstable nation to develop nuclear weapons by buying nuclear-reactor technology. "The contribution of the civil nuclear system to proliferation is impossible to monetize," says Bunn. "But that would be the biggest externality."

Unstable fuel
Such costs, even if they cannot be quantified, do not apply only to nuclear. "If you're concerned about nuclear safeguard costs you have to look at the costs of other sources," says William Nuttall, a nuclear expert at the University of Cambridge, UK. Putting a figure on the Western military spending associated with maintaining fossil-fuel supplies from the Middle East is a politically contentious task. But various estimates, from tens of billions of dollars a year to more than a hundred billion, suggest there is a hidden subsidy for oil prices that might top 10%.

These arguments, although vital for policy-makers wondering what to encourage, will not on their own influence investors' decisions. But a final point in favour of nuclear comes from a source that the money men are used to listening to. Portfolio theory is an established way of generating a mix of investments that creates maximum return for a given level of risk. This, says Shimon Awerbuch, an economist at the University of Sussex, UK, is exactly how governments should approach energy decisions. "Talking about generating cost without also talking about financial risk is like watching a movie with the sound turned off," he says. "You miss a big part of the story."

In the case of electricity generation, 'risk' concerns the chance that fuel prices, be they uranium or gas, will go up. Hikes in oil prices have a similar knock-on effect to those of energy prices more generally — they reduce gross domestic product. The real cost of a fuel source, says Awerbuch, needs to take such risks into account. That is bad news for sources whose price fluctuates, such as gas, and good news for nuclear, as uranium costs are reasonably steady, and likely to remain so unless there is an unparalleled boom in plant building.

Awerbuch's approach is to analyse the current mix of fuel sources in the economy to see what levels of risk governments are implicitly willing to accept. He then searches for other mixes that deliver the same risk at less cost. When trying out new combinations, something surprising can happen: adding an expensive non-fossil-fuel source such as nuclear or wind can actually decrease the overall cost. Nuclear lowers exposure to price hikes, and that lets planners simultaneously invest in riskier but cheaper sources such as gas. That additional gas more than compensates for the more expensive nuclear power, so overall prices fall. Although most of Awerbuch's work focuses on wind [4], his analysis also suggests that the steady price of uranium means nuclear should be retained as part of a healthy mix of generation sources.

When Awerbuch's way of looking at energy is combined with the recent rises in gas prices and, more significantly, the new carbon markets in Europe and the United States, another round of nuclear build seems a realistic possibility. A straw poll of nuclear experts shows they are starting to be convinced. Bunn used to offer straight bets against new nuclear construction starting in the coming decade. But put all these changes together, he says, and he might need to start offering odds. "Over 15 years," he adds, "I might switch my money to the other side."

See Editorial on page 969.


References
The Future of Nuclear Power: An Interdisciplinary MIT Study (Mass. Inst. Technol., 2003); published online http://web.mit.edu/nuclearpower
The Costs of Generating Electricity (R. Acad. Eng., London, 2004); published online http://213.130.42.236/wna_pdfs/rae-report.pdf
ExternE: Externalitites of Energy (European Commission, 1995).
Awerbuch, S. Mitigation Adapt. Strateg. Glob. Change (in the press).

[amit]

Regarding the cost of nuclear power vs coal and other high baseload generators, this study by Yangbo Du and John E. Parsons is supposed to be the one of the most authoritative.

It says:

Incorporating all cost elements, we find that the levelized cost of electricity from
nuclear power is 8.4¢/kWh, denominated in 2007 dollars. The levelized cost of electricity
from coal, exclusive of any carbon charge, is 6.2¢/kWh, denominated in 2007 dollars.
The levelized cost of electricity from gas, exclusive of any carbon charge, is 6.5¢/kWh,
denominated in 2007 dollars.

However, the report adds, referring to the MIT study which I listed above:

In its base case, the MIT (2003) study had applied a higher
cost of capital to nuclear power that it applied to either coal- or gas-fired power. The MIT
(2003) study also reported results with this risk premium removed so that a comparable
cost of capital was applied to both nuclear and coal-fired power, and we repeat that
calculation here: removing this risk premium from our calculations lowers the levelized
cost of electricity from nuclear power to 6.6¢/kWh. Adding a $25/tCO2 charge to coal and
gas-fired power raises the levelized cost of electricity from coal to 8.3¢/kWh and the
levelized cost of electricity from gas to 7.4¢/kWh.

Please note that the risk premium for nuclear power mentioned here is the regulatory instability caused by anti nuclear protestors or a sudden change in public opinion caused by a nuclear accident anywhere in the world. Source is here

[Sanku]

W.r.t. the article posted above by abhishek_sharma:

So essentially the selling of Nuclear energy is closely linked to Global warming myth making.

BTW fascinating tid-bit below? Is this true?

http://society.ezinemark.com/japan-nucl ... um=twitter

Japan Nuclear Crisis Tends Fears In India

However, the concerns on the nuclear safety in India are not just imaginary. If we look upon the last accident during 1993 that took place at the Narora atomic power plant is not far from the capital of India, New Delhi. During that time, the head of the countrys Atomic Energy Regulatory Board, Dr. A. Gopalakrishnan said that the major fire which took place in the Narora station got the reactor pretty close to meltdown.He added that the early morning blaze knocked out all the power to the plant and there by leaving the temperature of the reactor to rise out of control.

Gopalakrishna continued that a group of young engineers has worked by leaving no sign to the outside world and the youngsters took the decision of their own, not including any supervisory advice. He concluded that the people grabbed flashlights and climbed inside the reactor structure and has taken the right steps to get a hold of the situation under control. If the engineers could not take the correct steps then the two major cities namely Meerut and Aligarh would have been evacuated completely.

(Of course I know that Narora had a fire accident , the question is, is the above scale true?)

[amit]

^^^^

So essentially the selling of Nuclear energy is closely linked to Global warming myth making.

I'm sure the studies done by MIT and others are part of myth-making. Has to be so the Oracle has spoken.

[amit]

BTW fascinating tid-bit below? Is this true?

Must be true as it's not the concoction of some "nooklear expert". More power to sites like EzineMark.com and DailyStar and down with IAEA, I say!

[abhishek_sharma]

Nuclear energy: assessing the emissions: Kurt Kleiner reports on whether nuclear power deserves its reputation as a low-carbon energy source.

Nature Reports Climate Change
Published online: 24 September 2008 | doi:10.1038/climate.2008.99


http://www.nature.com/climate/2008/0810 ... 08.99.html

For decades nuclear power has been slated as being environmentally harmful. But with climate change emerging as the world's top environmental problem, the nuclear industry is now starting to enjoy a reputation as a green power provider, capable of producing huge amounts of energy with little or no carbon emissions [1]. As a result, the industry is gaining renewed support. In the United States, both presidential candidates view nuclear power as part of the future energy mix. The US government isn't alone in its support for an expansion of nuclear facilities. Japan announced in August that it would spend $4 billion on green technology, including nuclear plants.

But despite the enthusiasm for nuclear energy's status as a low-carbon technology, the greenhouse gas emissions of nuclear power are still being debated. While it's understood that an operating nuclear power plant has near-zero carbon emissions (the only outputs are heat and radioactive waste), it's the other steps involved in the provision of nuclear energy that can increase its carbon footprint. Nuclear plants have to be constructed, uranium has to be mined, processed and transported, waste has to be stored, and eventually the plant has to be decommissioned. All these actions produce carbon emissions.

Critics claim that other technologies would reduce anthropogenic carbon emissions more drastically, and more cost effectively. "The fact is, there's no such thing as a carbon-free lunch for any energy source," says Jim Riccio, a nuclear policy analyst for Greenpeace in Washington DC. "You're better off pursuing renewables like wind and solar if you want to get more bang for your buck." The nuclear industry and many independent analysts respond that the numbers show otherwise. Even taking the entire lifecycle of the plant into account nuclear energy still ranks with other green technologies, like solar panels and wind turbines, they say.

Life studies

Evaluating the total carbon output of the nuclear industry involves calculating those emissions and dividing them by the electricity produced over the entire lifetime of the plant. Benjamin K. Sovacool, a research fellow at the National University of Singapore, recently analyzed more than one hundred lifecycle studies of nuclear plants around the world, his results published in August in Energy Policy [2]. From the 19 most reliable assessments, Sovacool found that estimates of total lifecycle carbon emissions ranged from 1.4 grammes of carbon dioxide equivalent per kilowatt-hour (gCO2e/kWh) of electricity produced up to 288 gCO2e/kWh. Sovacool believes the mean of 66 gCO2e/kWh to be a reasonable approximation.

The large variation in emissions estimated from the collection of studies arises from the different methodologies used - those on the low end, says Sovacool, tended to leave parts of the lifecycle out of their analyses, while those on the high end often made unrealistic assumptions about the amount of energy used in some parts of the lifecycle. The largest source of carbon emissions, accounting for 38 per cent of the average total, is the "frontend" of the fuel cycle, which includes mining and milling uranium ore, and the relatively energy-intensive conversion and enrichment process, which boosts the level of uranium-235 in the fuel to useable levels. Construction (12 per cent), operation (17 per cent largely because of backup generators using fossil fuels during downtime), fuel processing and waste disposal (14 per cent) and decommissioning (18 per cent) make up the total mean emissions.

According to Sovacool's analysis, nuclear power, at 66 gCO2e/kWh emissions is well below scrubbed coal-fired plants, which emit 960 gCO2e/kWh, and natural gas-fired plants, at 443 gCO2e/kWh. However, nuclear emits twice as much carbon as solar photovoltaic, at 32 gCO2e/kWh, and six times as much as onshore wind farms, at 10 gCO2e/kWh. "A number in the 60s puts it well below natural gas, oil, coal and even clean-coal technologies. On the other hand, things like energy efficiency, and some of the cheaper renewables are a factor of six better. So for every dollar you spend on nuclear, you could have saved five or six times as much carbon with efficiency, or wind farms," Sovacool says. Add to that the high costs and long lead times for building a nuclear plant about $3 billion for a 1,000 megawatt plant, with planning, licensing and construction times of about 10 years and nuclear power is even less appealing.

Power games

But, says Paul Genoa, director of policy development for the Nuclear Energy Institute (NEI), a nuclear industry association based in Washington DC, "it's a fallacy to say one energy source is better, and that we should use it everywhere. The reality is that we need a portfolio solution that will include nuclear."

"If you look at lifecycle emissions from renewable technologies, typically they are on the order of only 1 to 5 per cent of a coal plant," says Paul Meier, director of the Energy Institute at the University of Wisconsin-Madison. Looked at as a replacement for fossil fuels, existing nuclear plants prevent 681 million tonnes of carbon from being emitted every year in the United States alone, according to the NEI.

Meier also points out that nuclear energy is capable of providing baseload power - that is, large amounts of power that can run consistently and reliably. Nuclear plants run 90 per cent of the time, while wind and solar power provide electricity only intermittently and have to be backed up, often by fossil fuel plants. "The modern electric grid relies on baseload power," says Genoa. "That's power that's running 24 hours a day, 365 days a year. It's only shut down for maintenance." Money spent on energy efficiency, however, is equivalent to increasing baseload power, since it reduces the overall power that needs to be generated, says Sovacool. And innovative energy-storage solutions, such as compressed air storage, could provide ways for renewables to provide baseload power.

Thomas Cochran, a nuclear physicist and senior scientist at the Natural Resources Defense Council (NRDC), an environmental group in Washington DC, says that although nuclear power has relatively low carbon emissions, it should not be subsidized by governments in the name of combating global warming. He argues that the expense and risk of building nuclear plants makes them uneconomic without large government subsidies, and that similar investment in wind and solar photovoltaic power would pay off sooner. "There are appropriate roles for federal subsidies in energy technologies," he says. "We subsidized heavily nuclear power when it was an emerging technology 30, 40, 50 years ago. Now it's a mature technology."

Nevertheless, the Energy Policy Act of 2005 saw the US Congress offer billions of dollars in tax breaks and loan guarantees in an attempt to kickstart construction. Although a number of utilities are pursuing licences for a total of 30 new nuclear plants in the United States, none have been approved yet. Even assuming that new subsidies were to increase US nuclear power by 1.5 times the current capacity, the result would be only an additional 510 megawatts per year from now until the year 2021. Wind power, the NRDC estimates, provides more than 1,000 megawatts a year, and that figure is likely to increase.

Another question has to do with the sustainability of the uranium supply itself. According to researchers in Australia at Monash University, Melbourne, and the University of New South Wales, Sydney, good-quality uranium ore is hard to come by. The deposits of rich ores with the highest uranium content are depleting leaving only lower-quality deposits to be exploited.3 As ore quality degrades, more energy is required to mine and mill it, and greenhouse gas emissions rise. "It is clear that there is a strong sensitivity of ... greenhouse gas emissions to ore grade, and that ore grades are likely to continue to decline gradually in the medium- to long-term," conclude the researchers.

But the nuclear industry points to technological advances of its own that are likely to make nuclear power less expensive and less carbon intensive. Genoa says that new methods of mining uranium and building reactors designed to run on less uranium-rich fuel could make nuclear power even more attractive. "If we're using the same reactors in two centuries, then we've missed the boat. There are going to be other technologies," Genoa says.


References
Solomon, S. et al. (eds.) Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge University Press, Cambridge and New York, 2007); http://www.ipcc.ch/pdf/assessment-repor ... g1-spm.pdf
Sovacool, B. Energy Policy 36, 2950–2963 (2008).
Mudd, G. M. & Diesendorf, M. Environ. Sci. Technol. 42, 2624–2630 (2008).

[abhishek_sharma]

Energy alternatives: Electricity without carbon

Published online 13 August 2008 | Nature 454, 816-823 (2008) | doi:10.1038/454816a

http://www.nature.com/news/2008/080813/ ... 4816a.html

Electricity generation provides 18,000 terawatt-hours of energy a year, around 40% of humanity's total energy use. In doing so it produces more than 10 gigatonnes of carbon dioxide every year, the largest sectoral contribution of humanity's fossil-fuel derived emissions. Yet there is a wide range of technologies — from solar and wind to nuclear and geothermal — that can generate electricity without net carbon emissions from fuel.

The easiest way to cut the carbon released by electricity generation is to increase efficiency. But there are limits to such gains, and there is the familiar paradox that greater efficiency can lead to greater consumption. So a global response to climate change must involve a move to carbon-free sources of electricity. This requires fresh thinking about the price of carbon, and in some cases new technologies; it also means new transmission systems and smarter grids. But above all, the various sources of carbon-free generation need to be scaled up to power an increasingly demanding world. In this special feature, Nature 's News team looks at how much carbon-free energy might ultimately be available — and which sources make most sense.

Hydropower


J. TAYLOR
The world has a lot of dams — 45,000 large ones, according to the World Energy Council, and many more at small scales. Its hydroelectric power plants have a generating capacity of 800 gigawatts (for a guide to power, see ‘By the numbers’), and they currently supply almost one-fifth of the electricity consumed worldwide. As a source of electricity, dams are second only to fossil fuels, and generate 10 times more power than geothermal, solar and wind power combined. With a claimed full capacity of 18 gigawatts, the Three Gorges dam in China can generate more or less twice as much power as all the world's solar cells. An additional 120 gigawatts of capacity is under development.

One reason for hydropower's success is that it is a widespread resource — 160 countries use hydropower to some extent. In several countries hydropower is the largest contributor to grid electricity — it is not uncommon in developing countries for a large dam to be the main generating source. Nevertheless, it is in large industrialized nations that have big rivers that hydroelectricity is shown in its most dramatic aspect. Brazil, Canada, China, Russia and the United States currently produce more than half of the world's hydropower.

Cost: According to the International Hydropower Association (IHA), installation costs are usually in the range of US$1 million to more than $5 million per megawatt of capacity, depending on the site and size of the plant. Dams in lowlands and those with only a short drop between the water level and the turbine tend to be more expensive; large dams are cheaper per watt of capacity than small dams in similar settings. Annual operating costs are low — 0.8–2% of capital costs; electricity costs $0.03–0.10 per kilowatt-hour, which makes dams competitive with coal and gas.

Capacity: The absolute limit on hydropower is the rate at which water flows downhill through the world's rivers, turning potential energy into kinetic energy as it goes. The amount of power that could theoretically be generated if all the world's run-off were 'turbined' down to sea level is more than 10 terawatts. However, it is rare for 50% of a river's power to be exploitable, and in many cases the figure is below 30%.

Those figures still offer considerable opportunity for new capacity, according to the IHA. Europe currently sets a benchmark for hydropower use, with 75% of what is deemed feasible already exploited. For Africa to reach the same level, it would need to increase its hydropower capacity by a factor of 10 to more than 100 gigawatts. Asia, which already has the greatest installed capacity, also has the greatest growth potential. If it were to triple its generating capacity, thus harnessing a near-European fraction of its potential, it would double the world's overall hydroelectric capacity. The IHA says that capacity could triple worldwide with enough investment.

Advantages: The fact that hydroelectric systems require no fuel means that they also require no fuel-extracting infrastructure and no fuel transport. This means that a gigawatt of hydropower saves the world not just a gigawatt's worth of coal burned at a fossil-fuel plant, but also the carbon costs of mining and transporting that coal. As turning on a tap is easy, dams can respond almost instantaneously to changing electricity demand independent of the time of day or the weather. This ease of turn-on makes them a useful back-up to less reliable renewable sources. That said, variations in use according to need and season mean that dams produce about half of their rated power capacity.

Hydroelectric systems are unique among generating systems in that they can, if correctly engineered, store the energy generated elsewhere, pumping water uphill when energy is abundant. The reservoirs they create can also provide water for irrigation, a way to control floods and create amenities for recreational use.

Disadvantages: Not all regions have large hydropower resources — the Middle East, for example, is relatively deficient. And reservoirs take up a lot of space; today the area under man-made lakes is as large as two Italys. The large dams and reservoirs that account for most of that area and for more than 90% of hydro-generated electricity worldwide require lengthy and costly planning and construction, as well as the relocation of people from the reservoir area. In the past few decades, millions of people have been relocated in India and China. Dams have ecological effects on the ecosystems upstream and downstream, and present a barrier to migrating fish. Sediment build-up can shorten their operating life, and sediment trapped by the dam is denied to those downstream. Biomass that decomposes in reservoirs releases methane and carbon dioxide, and in some cases these emissions can be of a similar order of magnitude to those avoided by not burning fossil fuels. Climate change could itself limit the capacity of dams in some areas by altering the amount and pattern of annual run-off from sources such as the glaciers of Tibet.

Because hydro is a mature technology, there is little room for improvement in the efficiency of generation. Also, the more obvious and easy locations have been used, and so the remaining potential can be expected to be harder to exploit. Small (less than 10 megawatts) 'run-of-river' schemes that produce power from the natural flow of water — as millers have been doing for four millennia — are appealing, as they have naturally lower impacts. However, they are about five times more expensive and harder to scale than larger schemes.

Verdict: A cheap and mature technology, but with substantial environmental costs; roughly a terawatt of capacity could be added.

Nuclear fission


When reactor 4 at the Chernobyl nuclear power plant in Ukraine melted down on 26 April 1986, the fallout contaminated large parts of Europe. That disaster, and the earlier incident at Three Mile Island in Pennsylvania, blighted the nuclear industry in the West for a generation. Worldwide, though, the picture did not change quite as dramatically.

In 2007, 35 nuclear plants were under construction, almost all in Asia. The 439 reactors already in operation had an overall capacity of 370 gigawatts, and contributed around 15% of the electricity generated worldwide, according to the most recent figures from the International Atomic Energy Agency (IAEA), which serves as the world's nuclear inspectorate.

Costs: Depending on the design of the reactor, the site requirements and the rate of capital depreciation, the light-water reactors that make up most of the world's nuclear capacity produce electricity at costs of between US$0.025 and $0.07 per kilowatt-hour. The technology that makes this possible has benefited from decades of expensive research, development and purchases subsidized by governments; without that boost it is hard to imagine that nuclear power would currently be in use.

Capacity: Because nuclear power requires fuel, it is constrained by fuel stocks. There are some 5.5 million tonnes of uranium in known reserves that could profitably be extracted at a cost of US$130 per kilogram or less, according to the latest edition of the 'Red Book', in which the IAEA and the Organisation for Economic Co-operation and Development (OECD) assess uranium resources. At the current use of 66,500 tonnes per year, that is about 80 years' worth of fuel. The current price of uranium is over that $130 threshold.

Geologically similar ore deposits that are as yet unproven — 'undiscovered reserves' — are thought to amount to roughly double the proven reserves, and lower-grade ores offer considerably more. Uranium is not a particularly rare element — it is about as common a constituent of Earth's crust as zinc. Estimates of the ultimate recoverable resource vary greatly, but 35 million tonnes might be considered available. Nor is uranium the only naturally occurring element that can be made into nuclear fuel. Although they have not yet been developed, thorium-fuelled reactors are a possibility; bringing thorium into play would double the available fuel reserves.

Furthermore, although current reactor designs use their fuel only once, this could be changed. Breeder reactors, which make plutonium from uranium isotopes that are not themselves useful for power production, can effectively create more fuel than they use. A system built on such reactors might get 60 times more energy out for every kilogram of natural uranium put in, although lower multiples might be more realistic.

With breeder reactors, which have yet to be proven on a commercial basis, the world could in principle go 100% nuclear. Without them, it is still plausible for the amount of nuclear capacity to grow by a factor of two or three, and to operate at that level for a century or more.

Advantages: Nuclear power has relatively low fuel costs and can run at full blast almost constantly — US plants deliver 90% of their rated capacity. This makes them well suited to providing always-on 'baseload' power to national grids. Uranium is sufficiently widespread that the world's nuclear-fuel supply is unlikely to be threatened by political factors.

Disadvantages: There is no agreed solution to the problem of how to deal with the nuclear waste that has been generated in nuclear plants over the past 50 years. Without long-term solutions, which are more demanding politically than technically, growth in nuclear power is an understandably hard sell. A further problem is that the spread of nuclear power is difficult to disentangle from the proliferation of nuclear weapons capabilities. Fuel cycles that involve recycling, and which thus necessarily produce plutonium, are particularly worrying. Even without proliferation worries, nuclear power stations may make tempting targets for terrorists or enemy forces (although in the latter case the same is true of hydroelectric plants).

A long-term commitment to greatly increased use of nuclear power would require public acceptance not just of existing technologies but of new ones, too — thorium and breeder reactors, for instance. These technologies would also have to win over investors and regulators (for nuclear fusion, see ‘Farther out’).

Nuclear power is also extremely capital intensive; power costs over the life of the plant are comparatively low only because the plants are long lived. Nuclear power is thus an expensive option in the short term. Another constraint may be a lack of skilled workers. Building and operating nuclear plants requires a great many highly trained professionals, and enlarging this pool of talent enough to double the rate at which new plants are brought online might prove very challenging. The engineering capacity for making key components would also need enlarging.

In light of these obstacles, predictions of the future role of nuclear power vary considerably. The European Commission's World Energy Technology Outlook — 2050 contains a bullish scenario that assumes that, with public acceptance and the development of new reactor technologies, nuclear power could provide about 1.7 terawatts by 2050. The IAEA's analysts are more cautious. Hans-Holger Rogner, head of the agency's planning and economic study section, sees capacity rising to not more than 1,200 gigawatts by 2050. An interdisciplinary study carried out in 2003 by the Massachusetts Institute of Technology described a concrete scenario for tripling capacity to 1,000 gigawatts by 2050, a scenario predicated on US leadership, continued commitment by Japan and renewed activity by Europe. This scenario relied only on improved versions of today's reactors rather than on any radically different or improved design.

Verdict: Reaching a capacity in the terawatt range is technically possible over the next few decades, but it may be difficult politically. A climate of opinion that came to accept nuclear power might well be highly vulnerable to adverse events such as another Chernobyl-scale accident or a terrorist attack.

Biomass


Biomass was humanity's first source of energy, and until the twentieth century it remained the largest; even today it comes second only to fossil fuels. Wood, crop residues and other biological sources are an important energy source for more than two billion people. Mostly, this fuel is burned in fires and cooking stoves, but over recent years biomass has become a source of fossil-fuel-free electricity. As of 2005, the World Energy Council estimates biomass generating capacity to be at least 40 gigawatts, larger than any renewable resource other than wind and hydropower. Biomass can supplement coal or in some cases gas in conventional power plants. Biomass is also used in many co-generation plants that can capture 85–90% of the available energy by making use of waste heat as well as electric power.

Costs: The price of biomass electricity varies widely depending on the availability and type of the fuel and the cost of transporting it. Capital costs are similar to those for fossil-fuel plants. Power costs can be as little as $0.02 per kilowatt-hour when biomass is burned with coal in a conventional power plant, but increase to $0.03–0.05 per kilowatt-hour from a dedicated biomass power plant. Costs increase to $0.04–0.09 per kilowatt-hour for a co-generation plant, but recovery and use of the waste heat makes the process much more efficient. The biggest problem for new biomass power plants is finding a reliable and concentrated feedstock that is available locally; keeping down transportation costs means keeping biomass power plants tied to locally available fuel and quite small, which increases the capital cost per megawatt.

Capacity: Biomass is limited by the available land surface, the efficiency of photosynthesis, and the supply of water. An OECD round table in 2007 estimated that there is perhaps half a billion hectares of land not in agricultural use that would be suitable for rain-fed biomass production, and suggested that by 2050 this land, plus crop residues, forest residues and organic waste might provide enough burnable material each year to provide 68,000 terawatt-hours. Converted to electricity at an efficiency of 40%, that could provide a maximum of 3 terawatts. The Intergovernmental Panel on Climate Change pegs the potential at roughly 120,000 terawatt-hours in 2050, which equates to slightly more than 5 terawatts on the basis of a larger estimate of available land.

These projections involve some fairly extreme assumptions about converting land to the production of energy crops. And even to the extent that these assumptions prove viable, electricity is not the only potential use for such plantations. By storing solar energy in the form of chemical bonds, biomass lends itself better than other renewable energy resources to the production of fuel for transportation (see page 841). Although turning biomass to biofuel is not as efficient as just burning the stuff, it can produce a higher-value product. Biofuels might easily beat electricity generation as a use for biomass in most settings.

Advantages: Plants are by nature carbon-neutral and renewable, although agriculture does use up resources, especially if it requires large amounts of fertilizer. The technologies needed to burn biomass are mature and efficient, especially in the case of co-generation. Small systems using crop residues can minimize transportation costs.

If burned in power plants fitted with carbon-capture-and-storage hardware, biomass goes from being carbon neutral to carbon negative, effectively sucking carbon dioxide out of the atmosphere and storing it in the ground (see 'Carbon capture and storage'). This makes it the only energy technology that can actually reduce carbon dioxide levels in the atmosphere. As with coal, however, there are costs involved in carbon capture, both in terms of capital set-up and in terms of efficiency.

Disadvantages: There is only so much land in the world, and much of it will be needed to provide food for the growing global population. It is not clear whether letting market mechanisms drive the allocation of land between fuel and food is desirable or politically feasible. Changing climate could itself alter the availability of suitable land. There is likely to be opposition to increased and increasingly intense cultivation of energy crops. Use of waste and residues may remove carbon from the land that would otherwise have enriched the soil; long-term sustainability may not be achievable.

Bioenergy dependence could also open the doors to energy crises caused by drought or pestilence, and land-use changes can have climate effects of their own: clearing land for energy crops may produce emissions at a rate the crops themselves are hard put to offset.

Verdict: If a large increase in energy crops proves acceptable and sustainable, much of it may be used up in the fuel sector. However, small-scale systems may be desirable in an increasing number of settings, and the possibility of carbon-negative systems — which are plausible for electricity generation but not for biofuels — is a unique and attractive capability.

Wind


Wind power is expanding faster than even its fiercest advocates could have wished a few years ago. The United States added 5.3 gigawatts of wind capacity in 2007 — 35% of the country's new generating capacity — and has another 225 gigawatts in the planning stages. There is more wind-generating capacity being planned in the United States than for coal and gas plants combined. Globally, capacity has risen by nearly 25% in each of the past five years, according to the Global Wind Energy Council.

Wind Power Monthly estimates that the world's installed capacity for wind as of January 2008 was 94 gigawatts. If growth continued at 21%, that figure would triple over six years.

Despite this, the numbers remain small on a global scale, especially given that wind farms have historically generated just 20% of their capacity.

Costs: Installation costs for wind power are around US$1.8 million per megawatt for onshore developments and between $2.4 million and $3 million for offshore projects. That translates to $0.05–0.09 per kilowatt-hour, making wind competitive with coal at the lower end of the range. With subsidies, as enjoyed in many countries, the costs come in well below those for coal — hence the boom. The main limit on wind-power installation at the moment is how fast manufacturers can make turbines.

These costs represent significant improvements in the technology. In 1981, a wind farm might have consisted of an array of 50-kilowatt turbines that produced power for roughly $0.40 per kilowatt-hour. Today's turbines can produce 30 times as much power at one-fifth the price with much less down time.

Capacity: The amount of energy generated by the movement of Earth's atmosphere is vast — hundreds of terawatts. In a 2005 paper, a pair of researchers from Stanford University calculated that at least 72 terawatts could be effectively generated using 2.5 million of today's larger turbines placed at the 13% of locations around the world that have wind speeds of at least 6.9 metres per second and are thus practical sites (C. L. Archer and M. Z. Jacobson J. Geophys. Res. 110, D12110; 2005).

Advantages: The main advantage of wind is that, like hydropower, it doesn't need fuel. The only costs therefore come from building and maintaining the turbines and power lines. Turbines are getting bigger and more reliable. The development of technologies for capturing wind at high altitudes could provide sources with small footprints capable of generating power in a much more sustained way.

Disadvantages: Wind's ultimate limitation might be its intermittency. Providing up to 20% of a grid's capacity from wind is not too difficult. Beyond that, utilities and grid operators need to take extra steps to deal with the variability. Another grid issue, and one that is definitely limiting in the near term, is that the windiest places are seldom the most populous, and so electricity from the wind needs infrastructure development — especially for offshore settings.


Average power of the world's winds during the boreal winter (top) and summer. The recoupable energy is some two orders of magnitude lower because of turbine spacing and engineering constraints. Courtesy: W. T. Liu et al. Geophys. Res. Lett. 35, L13808 (2008).

As well as being intermittent, wind power is, like other renewable energy sources, inherently quite low density. A large wind farm typically generates a few watts per square metre — 10 is very high. Wind power thus depends on cheap land, or on land being used for other things at the same time, or both. It is also hard to deploy in an area where the population sets great store by the value of a turbine-free landscape.

Wind power is also unequally distributed: it favours nations with access to windy seas and their onshore breezes or great empty plains. Germany has covered much of its windiest land with turbines, but despite these pioneering efforts, its combined capacity of 22 GW supplies less than 7% of the country's electricity needs. Britain, which has been much slower to adopt wind power, has by far the largest offshore potential in Europe — enough to meet its electricity needs three times over, according to the British Wind Energy Association. Industry estimates suggest that the European Union could meet 25% of its current electricity needs by developing less than 5% of the North Sea.

Such truly large-scale deployment of wind-power schemes could affect local, and potentially global, climate by altering wind patterns, according to research by David Keith, head of the Energy and Environmental Systems Group at the University of Calgary in Canada. Wind tends to cool things down, so temperatures around a very large wind farm could rise as turbines slow the wind to extract its energy. Keith and his team suggest that 2 TW of wind capacity could affect temperatures by about 0.5 °C, with warming at mid-latitudes and cooling at the poles — perhaps in that respect offsetting the effect of global warming (D. W. Keith et al. Proc. Natl Acad. Sci. USA 101, 16115–16120; 2004).

Verdict: With large deployments on the plains of the United States and China, and cheaper access to offshore, a wind-power capacity of a terawatt or more is plausible.

Geothermal


Earth's interior contains vast amounts of heat, some of it left over from the planet's original coalescence, some of it generated by the decay of radioactive elements. Because rock conducts heat poorly, the rate at which this heat flows to the surface is very slow; if it were quicker, Earth's core would have frozen and its continents ceased to drift long ago.

The slow flow of Earth's heat makes it a hard resource to use for electricity generation except in a few specific places, such as those with abundant hot springs. Only a couple of dozen countries produce geothermal electricity, and only five of those — Costa Rica, El Salvador, Iceland, Kenya and the Philippines — generate more than 15% of their electricity this way. The world's installed geothermal electricity capacity is about 10 gigawatts, and is growing only slowly — about 3% per year in the first half of this decade. A decade ago, geothermal capacity was greater than wind capacity; now it is almost a factor of ten less.

Earth's heat can also be used directly. Indeed, small geothermal heat pumps that warm houses and businesses directly may represent the greatest contribution that Earth's warmth can make to the world's energy budget.

Costs: The cost of a geothermal system depends on the geological setting. Jefferson Tester, a chemical engineer who was part of a team that produced an influential Massachusetts Institute of Technology (MIT) report on geothermal technology in 2006, explains the situation as being “similar to mineral resources. There is a continuum of resource grades — from shallow, high-temperature regions of high-porosity rock, to deeper low-porosity regions that are more challenging to exploit”. That report put the cost of exploiting the best sites — those with a lot of hot water circulating close to the surface — at about US$0.05 per kilowatt-hour. Much more abundant low-grade resources are exploitable with current technology only at much higher prices.

Absolute capacity: Earth loses heat at between 40 TW and 50 TW a year, which works out at an average of a bit less than a tenth of a watt per square metre. For comparison, sunlight comes in at an average of 200 watts per square metre. With today's technology, 70 GW of the global heat flux is seen as exploitable. With more advanced technologies, at least twice that could be used. The MIT study suggested that using enhanced systems that inject water at depth using sophisticated drilling systems, it would be possible to set up 100 GW of geothermal electricity in the United States alone. With similar assumptions a global figure of a terawatt or so can be reached, suggesting that geothermal could, with a great deal of investment, provide as much electricity as dams do today.

Advantages: Geothermal resources require no fuel. They are ideally suited to supplying base-load electricity, because they are driven by a very regular energy supply. At 75%, geothermal sources boast a higher capacity factor than any other renewable. Low-grade heat left over after generation can be used for domestic heating or for industrial processes.

Surveying and drilling previously unexploited geothermal resources has become much easier thanks to mapping technology and drilling equipment designed by the oil industry. A significant technology development programme — Tester suggests $1 billion over 10 years — could greatly expand the achievable capacity as lower-grade resources are opened up.

Disadvantages: High-grade resources are quite rare, and even low-grade resources are not evenly distributed. Carbon dioxide can leak out of some geothermal fields, and there can be contamination issues; the water that brings the heat to the surface can carry compounds that shouldn't be released into aquifers. In dry regions, water availability can be a constraint. Large-scale exploitation requires technologies that, although plausible, have not been demonstrated in the form of robust, working systems.

Verdict: Capacity might be increased by more than an order of magnitude. Without spectacular improvements, it is unlikely to outstrip hydro and wind and reach a terawatt.

Solar


Not to take anything away from the miracle of photosynthesis, but even under the best conditions plants can only turn about 1% of the solar radiation that hits their surfaces into energy that anyone else can use. For comparison, a standard commercial solar photovoltaic panel can convert 12–18% of the energy of sunlight into useable electricity; high-end models come in above 20% efficiency. Increasing manufacturing capacity and decreasing costs have led to remarkable growth in the industry over the past five years: in 2002, 550 MW of cells were shipped worldwide; in 2007 the figure was six times that. Total installed solar-cell capacity is estimated at 9 GW or so. The actual amount of electricity generated, though, is considerably less, as night and clouds decrease the power available. Of all renewables, solar currently has the lowest capacity factor, at about 14%.

Solar cells are not the only technology by which sunlight can be turned into electricity. Concentrated solar thermal systems use mirrors to focus the Sun's heat, typically heating up a working fluid that in turn drives a turbine. The mirrors can be set in troughs, in parabolas that track the Sun, or in arrays that focus the heat on a central tower. As yet, the installed capacity is quite small, and the technology will always remain limited to places where there are a lot of cloud-free days — it needs direct sun, whereas photovoltaics can make do with more diffuse light.

Costs: The manufacturing cost of solar cells is currently US$1.50–2.50 for a watt's worth of generating capacity, and prices are in the $2.50–3.50 per watt range. Installation costs are extra; the price of a full system is normally about twice the price of the cells. What this means in terms of cost per kilowatt-hour over the life of an installation varies according to the location, but it comes out at around $0.25–0.40. Manufacturing costs are dropping, and installation costs will also fall as photovoltaic cells integrated into building materials replace free-standing panels for domestic applications. Current technologies should be manufacturing at less than $1 per watt within a few years (see Nature 454, 558–559; 2008).

The cost per kilowatt-hour of concentrated solar thermal power is estimated by the US National Renewable Energy Laboratory (NREL) in Golden, Colorado, at about $0.17.

Capacity: Earth receives about 100,000 TW of solar power at its surface — enough energy every hour to supply humanity's energy needs for a year. There are parts of the Sahara Desert, the Gobi Desert in central Asia, the Atacama in Peru or the Great Basin in the United States where a gigawatt of electricity could be generated using today's photovoltaic cells in an array 7 or 8 kilometres across. Theoretically, the world's entire primary energy needs could be served by less than a tenth of the area of the Sahara.

Advocates of solar cells point to a calculation by the NREL claiming that solar panels on all usable residential and commercial roof surfaces could provide the United States with as much electricity per annum as the country used in 2004. In more temperate climes things are not so promising: in Britain one might expect an annual insolation of about 1,000 kilowatt-hours per metre on a south-facing panel tilted to take account of latitude: at 10% efficiency, that means more than 60 square metres per person would be needed to meet current UK electricity consumption.

Advantages: The Sun represents an effectively unlimited supply of fuel at no cost, which is widely distributed and leaves no residue. The public accepts solar technology and in most places approves of it — it is subject to less geopolitical, environmental and aesthetic concern than nuclear, wind or hydro, although extremely large desert installations might elicit protests.

Photovoltaics can often be installed piecemeal — house by house and business by business. In these settings, the cost of generation has to compete with the retail price of electricity, rather than the cost of generating it by other means, which gives solar a considerable boost. The technology is also obviously well suited to off-grid generation and thus to areas without well developed infrastructure.

Both photovoltaic and concentrated solar thermal technologies have clear room for improvement. It is not unreasonable to imagine that in a decade or two new technologies could lower the cost per watt for photovoltaics by a factor of ten, something that is almost unimaginable for any other non-carbon electricity source.

Disadvantages: The ultimate limitation on solar power is darkness. Solar cells do not generate electricity at night, and in places with frequent and extensive cloud cover, generation fluctuates unpredictably during the day. Some concentrated solar thermal systems get around this by storing up heat during the day for use at night (molten salt is one possible storage medium), which is one of the reasons they might be preferred over photovoltaics for large installations. Another possibility is distributed storage, perhaps in the batteries of electric and hybrid cars (see page 810).

Another problem is that large installations will usually be in deserts, and so the distribution of the electricity generated will pose problems. A 2006 study by the German Aerospace Centre proposed that by 2050 Europe could be importing 100 GW from an assortment of photovoltaic and solar thermal plants across the Middle East and North Africa. But the report also noted that this would require new direct-current high-voltage electricity distribution systems.

A possible drawback of some advanced photovoltaic cells is that they use rare elements that might be subject to increases in cost and restriction in supply. It is not clear, however, whether any of these elements is either truly constrained — more reserves might be made economically viable if demand were higher — or irreplaceable.

Verdict: In the middle to long run, the size of the resource and the potential for further technological development make it hard not to see solar power as the most promising carbon-free technology. But without significantly enhanced storage options it cannot solve the problem in its entirety.

Ocean energy


The oceans offer two sorts of available kinetic energy — that of the tides and that of the waves. Neither currently makes a significant contribution to world electricity generation, but this has not stopped enthusiasts from developing schemes to make use of them. There are undoubtedly some places where, thanks to peculiarities of geography, tides offer a powerful resource. In some situations that potential would best be harnessed by a barrage that creates a reservoir not unlike that of a hydroelectric dam, except that it is refilled regularly by the pull of the Moon and the Sun, rather than being topped up slowly by the runoff of falling rain. But although there are various schemes for tidal barrages under discussion — most notably the Severn Barrage between England and Wales, which proponents claim could offer as much as 8 GW — the plant on the Rance estuary in Brittany, rated at 240 MW, remains the world's largest tidal-power plant more than 40 years after it came into use.

There are also locations well suited to tidal-stream systems — submerged turbines that spin in the flowing tide like windmills in the air. The 1.2 MW turbine installed this summer in the mouth of Strangford Lough, Northern Ireland, is the largest such system so far installed.

Most technologies for capturing wave power remain firmly in the testing phase. Individual companies are working through an array of potential designs, including machines that undulate on waves like a snake, bob up and down as water passes over them, or nestle on the coastline to be regularly overtopped by waves that power turbines as the water drains off. The European Marine Energy Centre's test bed off the United Kingdom's Orkney Islands, where manufacturers can hook up prototypes to a marine electricity grid and test how well they withstand the pounding waves, is a leading centre of research. Pelamis Wave Power, a company based in Edinburgh, UK, for instance, has moved from testing there to installing three machines off the coast of Portugal, which together will eventually generate 2.25 MW.

Costs: Barrage costs differ markedly from site to site, but are broadly comparable to costs for hydropower. At an estimated cost of £15 billion (US$30 billion) or more, the capital costs of the Severn Barrage would be about $4 million per megawatt. A 2006 report from the British Carbon Trust, which spurs investment in non-carbon energy, puts the costs of tidal-stream electricity in the $0.20–0.40 per kilowatt-hour range, with wave systems running up to $0.90 per kilowatt-hour. Neither technology is anywhere close to the large-scale production needed to significantly drive such costs down.

Capacity: The interaction of Earth's mass with the gravitational fields of the Moon and the Sun is estimated to produce about 3 TW of tidal energy— rather modest for such an astronomical source (although enough to play a key role in keeping the oceans mixed — see Nature 447, 522–524; 2007). Of this, perhaps 1 TW is in shallow enough waters to be easily exploited, and only a small part of that is realistically available. EDF, a French power company developing tidal power off Brittany, says that the tidal-stream potential off France is 80% of that available all round Europe, and yet it is still little more than a gigawatt.

The power of ocean waves is estimated at more than 100 TW. The European Ocean Energy Association estimates that the accessible global resource is between 1 and 10 terawatts, but sees much less than that as recoverable with current technologies. An analysis in the MRS Bulletin in April 2008 holds that about 2% of the world's coastline has waves with an energy density of 30 kW m−1, which would offer a technical potential of about 500 GW for devices working at 40% efficiency. Thus even with a huge amount of development, wave power would be unlikely to get close to the current installed hydroelectric capacity.

Advantages: Tides are eminently predictable, and in some places barrages really do offer the potential for large-scale generation that would be significant on a countrywide scale. Barrages also offer some built-in storage potential. Waves are not constant — but they are more reliable than winds.

Disadvantages: The available resource varies wildly with geography; not every country has a coastline, and not every coastline has strong tides or tidal streams, or particularly impressive waves. The particularly hot wave sites include Australia's west coast, South Africa, the western coast of North America and western European coastlines. Building turbines that can survive for decades at sea in violent conditions is tough. Barrages have environmental impacts, typically flooding previously intertidal wetlands, and wave systems that flank long stretches of dramatic coastline might be hard for the public to accept. Tides and waves tend by their nature to be found at the far end of electricity grids, so bringing back the energy represents an extra difficulty. Surfers have also been known to object …

Verdict: Marginal on the global scale.

See Editorial, page 805.
Reported and written by Quirin Schiermeier, Jeff Tollefson, Tony Scully, Alexandra Witze and Oliver Morton.
References
Key World Energy Statistics 2007 (International Energy Agency, 2007).
Hohmeyer, O. & Trittin, T. (eds) Proc. IPCC Scoping Meeting on Renewable Energy Sources 20–25 January 2008, Lübeck, Germany (Intergovernmental Panel on Climate Change, 2008).
Smil, V. Energy in Nature and Society: General Energetics of Complex Systems (MIT Press, 2008).
Metz, B., Davidson, O., Bosch, P., Dave, R. & Meyer, L. (eds) Climate Change 2007: Mitigation of Climate Change (Cambridge Univ. Press, 2007).

[amit]

^^^^^^

From the article posted before the last one by Abhishek:

But, says Paul Genoa, director of policy development for the Nuclear Energy Institute (NEI), a nuclear industry association based in Washington DC, "it's a fallacy to say one energy source is better, and that we should use it everywhere. The reality is that we need a portfolio solution that will include nuclear."

This works both ways. Which is why many here - certainly myself - have been crying hoarse that India cannot afford to shun nuclear power and we need to learn from Fukushima how to make nuclear power plants more safe.

Unfortunately sensationalism and doomsday posting always wins the day due to sheer persistence and noise value.

[abhishek_sharma]

On the first question, taking Chernobyl as an example, cost estimates range from 4 billion dollars to 20-25 billion dollars...And Chernobyl was perhaps the blackest of all black swans..To put things in perspective, the BP payout to the US govt, is estimated to be 30 billion dollars in various forms..

Really? So BP oil spill was worse than Chernobyl ? Right?

[Sanku]

[chaanakya]

^^^^^^

From the article posted before the last one by Abhishek:

But, says Paul Genoa, director of policy development for the Nuclear Energy Institute (NEI), a nuclear industry association based in Washington DC, "it's a fallacy to say one energy source is better, and that we should use it everywhere. The reality is that we need a portfolio solution that will include nuclear."

Has he been able to convince USA to build more nuclear reactors for power generation. How many have they build for last ten years? Why USA persistently refused to ratify Kyoto protocol and what did he do to address the carbon concerns in USA?

Can anyone answer that, please?

[GuruPrabhu]

Unfortunately sensationalism and doomsday posting always wins the day due to sheer persistence and noise value.

very true, amit Saar. Now combine this with "BRF ahead of the curve" business and you can see a nation going down this path. Hysteria has defeated science. The sooner you accept this, the easier it becomes to watch the cacophony from a distance. Bhabha never figured the hysterical Indian in his plan.

I am investing in gas futures. We will pay through our noses for electricity, so compensate for it by investing in gas companies.

[Lalmohan]

gobar gas?

[somnath]

Really? So BP oil spill was worse than Chernobyl ? Right?

You obvioulsy didnt get the message in that post, maybe it was a genuine misinterpretation...

The example was simply in response to Joe Stiglitz's axiom on outsized costs of black swan accidents in nuke power..The point is being made is a) large costs of industrial accidents are not unique to nukes, not anymore, and b) it is not necessary that the reparation is borne excusively by the state...The BP example counters both the above...

Now if BP (and other oil comapnies) was asked to take a 30 billion third party insurance every time they drilled in deep sea, all deep sea exploration would instantly stop..Guess what that would do to oil prices?

Therefore, the fundamental assumption that "large value" black swan accidents are archetypal of nukes is not true anymore..And depending on the situation, the pvt sector too can be made to pay the damages...Thats the limited point...

[GuruPrabhu]

gobar gas?

Saar, it is now known with the fancy name "Bio-mass". The greens like it but it has a large carbon footprint.

However, any money invested in this sector will have you adding to the gas production.

[somnath]

^^^Biomass carbon footprint is about 15-20 times that of nuclear, accrding to the study by the UK PArliamentary Office of Science and Tech - link posted before...

[Theo_Fidel]

Amit,

Amit as far as the supply of Uranium, read the report carefully, it says there is enough Uranium for 1000 reactors for 50 years. In other words there is enough for the existing reactors and the west. India's expansion is not accounted for. Right now Uranium is very cheap, on the order of $70 per pound. Still it costs about 25% of the operational cost. About 2 Cents a kilowatt. If a shortage happens and it spikes to $200 per pound you can see how quickly the price ramps up and becomes uneconomical with even solar. Also keep in mind that nuclear only supplies 5% of global electricity after all this tamasha. It not expected to rise much above 10% even after all the expansion. Is it worth it. We are taking on a awful lot of risk for very little power.

Also that decommissioning report assumes plants be safe stored for lengthy periods and most of the low level radioactivity left on site. Most states now will not let this happen and expect the operator to return the site to pre-operational levels. There hasn't been a proper plant decommissioned in the US since 1998 so it is kinda hard to know what the costs are right now. Also the costs for the long term handling of the low level and high level waste is conveniently not included. The entire industry dances around this issue assuming someone else will assume this cost. Also none of these decommissioning plans account for surprises or any sort of accident clean up.

Yes, I have admitted that Solar is expensive up front. But once you add the insurance and safety risk costs and the danger of being dependent on yet another foreign energy source, Solar Thermal starts becoming more and more attractive. We have the manpower and technical ability now to build/operate these plants at a much lower cost than Spain. Exactly how is Kudankulam insured BTW. No one can answer this question because it is not insured. Think about that before looking at costs. An uninsured nuclear plant sitting in your backyard.

Also Nuclear is NOT carbon free, it is operationally low carbon, but in its total life cycle it is not. This is true of all energy sources. Where do you think all those millions of tonnes of concrete comes from. Or that steel.

[chaanakya]

^^ Theo ji its convenient to overlook other aspects a so as to propose , seemingly, a robust case.

Even US , as well as India, proposes to achieve coal parity by 2032 or so. In fact cost of Solar PV is decreasing . At least I know it has come down from 18 cr to 11 cr, not talking of Chinese SPV. The other issue of land requirement is about 5 acres which in some cases have been reduced to 2.5 acres. Panel efficiency is increased to about 40% in one R&D project.

Thermal plants , in India have 18-20 % efficiency. While in Japan and USA it is 35 to 40%. SO if one upgrades existing plants and probably employs better technology it might be more effective.

Besides there are energy efficiency and conservation and T&D or AT&C related improvements which would reap better rewards and all additions from increasing 2.5% to 20 % of NPP in India.

The proponents also forget that US has not added any single plant and not signed carbon pledge. But they would force this on India . B-ji has asked one question about climate modelling and weather forecasting and also about the doctoring of glacial melt data supposed to be caused by global warming (IPCC) and everyone is looking the other way.