Bharat Rakshak

The cost of solar panels is dropping exponentially. The first and most important technological change is the falling cost per watt of silicon photovoltaic cells over the past few decades. Check out the plummeting cost from $76 in 1977, to less than $0.36 toda

There's a growing hubbub in the plug-in vehicle community over what looks like some ridiculously cheap replacement batteries for the Chevrolet Volt going up for sale. GM Parts Online, for example, is selling a replacement Volt battery with an MSRP of $2,994.64 but, with an online discount, the price comes down to $2,305.88. For the 16-kWh pack in the 2012 Volt, that comes to a very low $144.11 per kilowatt hour (kWH). But is it a real deal? How can it be, when a Chevy dealer may quote you a price of up to $34,000 to replace the pack?

For a 16-kWh Volt pack, $2,305.88 comes to a very low $144.11 per kWh. But is it a real deal?

Battery packs in alternative propulsion vehicles are usually priced by the kWh and, historically, they've been thought to be in the range of $500-per-kWh for OEM offerings. Since automakers are understandably secretive about their costs, we still don't know what the real number is today, but we do know it varies by automaker. Tesla, for example, has said it pays less than $200-per-kWH at the cell level but, of course, a constructed pack would be more. Whatever is going on, li-ion battery prices are trending downward.

So, $144.11 certainly sounds great, but what's the story here? Kevin Kelly, manager of electrification technology communications for General Motors, reminded AutoblogGreen that GM Parts Online is not the official GM parts website and that, "the costs indicated on the site are not what we would charge our dealers or owners for a replacement battery. There would be no cost to the Volt owner if their battery needs replacement or repair while the battery is under the eight year/100,000 mile limited warranty coverage provided by Chevrolet."

There's a growing hubbub in the plug-in vehicle community over what looks like some ridiculously cheap replacement batteries for the Chevrolet Volt going up for sale. GM Parts Online, for example, is selling a replacement Volt battery with an MSRP of $2,994.64 but, with an online discount, the price comes down to $2,305.88. For the 16-kWh pack in the 2012 Volt, that comes to a very low $144.11 per kilowatt hour (kWH). But is it a real deal? How can it be, when a Chevy dealer may quote you a price of up to $34,000 to replace the pack?

For a 16-kWh Volt pack, $2,305.88 comes to a very low $144.11 per kWh. But is it a real deal?

Battery packs in alternative propulsion vehicles are usually priced by the kWh and, historically, they've been thought to be in the range of $500-per-kWh for OEM offerings. Since automakers are understandably secretive about their costs, we still don't know what the real number is today, but we do know it varies by automaker. Tesla, for example, has said it pays less than $200-per-kWH at the cell level but, of course, a constructed pack would be more. Whatever is going on, li-ion battery prices are trending downward.

So, $144.11 certainly sounds great, but what's the story here? Kevin Kelly, manager of electrification technology communications for General Motors, reminded AutoblogGreen that GM Parts Online is not the official GM parts website and that, "the costs indicated on the site are not what we would charge our dealers or owners for a replacement battery. There would be no cost to the Volt owner if their battery needs replacement or repair while the battery is under the eight year/100,000 mile limited warranty coverage provided by Chevrolet."

The firm’s Chief Risk Officer, Wolfgang Juilfs, told BusinessLine on Sunday that the company has started offering machines of rated capacity of 3.5MW. It is developing suppliers for the machines, which will come in two versions — one with blades that will sweep a circle of 138 metrrs and the other 126 metres.

The height of the tower on top of which the turbines would be placed will depend upon the site, but it could be as high as 131 metres, in which case the tower will be a hybrid of a concrete structure and tubular steel, Juilfs said.

He said wind energy companies could participate in competitive bids now if the projects need to be commissioned by 2019-20end. Enercon will be ready with its machines by then. These, then, will be the biggest wind turbines to be sold in India.

The Indian market is dominated by machines of a nominal capacity of around 2MW and 120 metre high. The only other company to have a 3MW machine is another German company, Nordex.

Renewable solution provider Suzlon Group today announced the installation and commissioning of its new product, S128, claiming it to be the largest wind turbine generator (WTG) in India.

The first prototype of S128 has been commissioned at the Sanganeri site in Tamil Nadu, a company statement said, adding that testing is underway with certification expected in third quarter of calendar year 2018.

The company said that the S128 WTG is available in 2.6 MW to 2.8 MW variants and offers hub heights up to 140 metres. The S128 wind turbine generator is the latest addition to Suzlon's product portfolio and features the doubly fed induction generator (DFIG) technology.

The company claimed that the wind mill also consists of the country's largest rotor blade measuring 63 meters and has a rotor diameter of 128 meters. The SB 63 blade has been engineered and developed by Suzlon utilising carbon fibre which provides the capability to utilise thinner aerodynamic profiles.

This next generation turbine is well equipped to improve energy yield and support competitive tariff environment in India while protecting customers return on investment (ROI).

"Poo to Power" may sound awkward and impractical, but Aditya Aggarwal and his brother Amit have done it in Karnal, Haryana. Two industries, one producing wire nails and another tinner rivets, owned by the family run on 100% electricity produced from cattle dung they get from nearby 'gaushalas' or cow sheds. The cattle dung-based power plant started in 2014 and that too without government support. The bio-gas plant generates close to two megawatts of power daily.

Sukhbir Singh of Silani village in Jhajjar stumbled on the idea to produce electricity from chicken faeces at his poultry farm to escape the clutches of corrupt electricity department officials in 2010. Singh, his father Subedar (retired) Ram Mehar and brother Ranbir had several cases against the local electricity department. Today, their bio-gas plants generate enough power to meet most of the electricity needs of four poultry farms.

Such real life change-makers and several others like them in Punjab, Uttarakhand and Tamil Nadu have come in handy for the Modi government to make its "Gobar-Dhan" scheme distinct from other government schemes by encouraging entrepreneurs to convert cow dung and other bio-mass available in rural areas to generate electricity, gas and fertiliser and make it a part of their business model.

According to government estimates, India has about 30 crore cattle population and about 30 lakh tonnes of cattle dung is produced daily. This can be a major source for bio-gas and manure. The government plans to roll out the scheme across 350 districts in the first phase and cover the rest during the second phase. In 2018-19, it targets to set up about 700 bio-gas plants across the country by providing performance-based incentives to gram panchayats, self help groups (SGHs) and bulk generators like gaushalas. Officials say government will provide 25% advance amount as incentive for panchayats and SGHs.

With the countries across the globe gradually moving towards clean energy in sync with their goals under the Paris Agreement on climate change, jobs in the renewable energy sector globally crossed 10 million mark in 2017. All the countries together had created over half-a-million new jobs in the sector last year, a 5.3% increase from 2016.

Though most of the countries are making efforts to move towards low-carbon economy, six of them - China, Brazil, the United States, India, Germany and Japan - have constantly been on clean energy path with representing more than 70% of jobs globally in the renewable sector.

The figures show that the solar photovoltaic (PV) industry remains the largest employer of all RE technologies, accounting for close to 3.4 million jobs worldwide including 2.2 million jobs in China and 1,64,000 jobs in India.

Biofuels, hydro-power (both small and large) and wind are the other three segments in the RE sector which employ maximum number of people across the globe. With China and India moving fast towards solar and wind, 60% of all renewable energy jobs are in Asia.

India has set a target of installing 175 GW of renewable power by 2022. This includes 100 GW from solar power, 60 GW from wind power, 10 GW from biomass power and 5 GW from small hydro power. India’s cumulative solar installations stand at 19.6 GW as on December, 2017. The country had added record 9.6 GW of solar power last year - over 10% of what all the countries together installed (94GW) in 2017.

According to Mercom Communications India, Karnataka and Telangana had installed the highest amounts of utility-scale solar capacity, adding roughly 2.1 GW each, in 2017. Together, they accounted for approximately 50% of the total capacity added in India last year. Andhra Pradesh was ranked third with 1,225 MW of solar installed.

India’s solar power installation growth is, however, being largely driven by imported modules. The IRENA’s annual review noted that the manufacturing of solar PV modules is limited in the country, given the availability of inexpensive imports, mostly from China.

“The market share of domestic firms decreased from 13% in 2014-15 to 7% in 2017-18. As of September 2017, the average price for imported modules was USD 0.39 per Watt compared with USD 1.44 per Watt for domestic products and a large share of the existing manufacturing capacity stands idle”, said the IRENA’s review report.

“We build solar all over the world but China is the only place where every component we need is available just a few kilometers away. If we need something, we can get it in an hour. No shipping. No contracts. It just shows up in a pickup truck. The key is to keep our factories running continuously and, in China, we have everything we need close by.”

The one megawatt-capacity plant, implemented by the Arunachal Pradesh Energy Development Agency (APEDA), was commissioned on April 1 this year with an estimated cost of Rs 850 lakh received as incentive grant under the 13th finance commission. The work on the plant began on April 19, 2016 and was completed on March 30 this year. Harayana-based M/S Dynamic Powers executed the work on the plant.

He [Pema Khandu] said work is going on to fulfil the target set by the Centre for rural electrification within this year under Deen Dayal Upadhyaya Gram Jyoti Yojana (DDUGJY). "As of now, 10% off-grid power connectivity in villages of the state are being implemented by the APEDA and the state government is contemplating to install solar plants in various health centres and upcoming mini-secretariats in the districts," the chief minister said.

nandakumar wrote:https://oilprice.com/Energy/Energy-Gene ... Metal.html
This article says Vanadium is the new energy storage medium. It can be scaled up at decreasing unit cost of such storage. Don't know how close the world is to adopting it. But there it is.

Insecurity of supply

With vanadium demand set to soar, it is a valid question as to where new vanadium supply will come from. There are currently no North American reserves, a situation that is and should be deeply alarming to politicians on both sides of the 49th parallel.

A critical or strategic metal is defined as one whose lack of availability during a national emergency would affect the economic and defensive capabilities of that country. The United States and Canada, are completely dependent on recycling (mostly through recovery from spent catalyst from oil refining operations) and imports for 100% of their vanadium supply.

Consider what happened to the rare earths market in the 2000s, when China, which produces 90 percent of REEs, restricted exports, causing prices to spike around the world. Rare earths are used in everything from cell phones to wind turbines to missile guidance systems. With just three countries – South Africa, China and Russia – controlling the supply of vanadium, there is a high risk of that supply either being cut off due to a political or trade conflict, or for the price to suddenly jump.

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About 96% of the world’s energy-storage capacity comes in the form of one technology: pumped hydro. Whenever generation exceeds demand, the excess electricity is used to pump water up a dam. When demand exceeds generation, that water is allowed to fall—thanks to gravity—and the potential energy turns turbines to produce electricity.

But pumped-hydro storage requires particular geographies, with access to water and to reservoirs at different altitudes. It’s the reason that about three-quarters of all pumped hydro storage has been built in only 10 countries. The trouble is the world needs to add a lot more energy storage, if we are to continue to add the intermittent solar and wind power necessary to cut our dependence on fossil fuels.

A startup called Energy Vault thinks it has a viable alternative to pumped-hydro: Instead of using water and dams, the startup uses concrete blocks and cranes. It has been operating in stealth mode until today (Aug. 18), when its existence will be announced at Kent Presents, an ideas festival in Connecticut.

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Yet, this colourful goop, developed at the University of Toronto, does something that researchers say could make it a real-life blockbuster. When spread on a strip of metal and subjected to an electric current, it can break apart molecules of water at about three times the rate and far more cheaply than any substance currently available. If its effectiveness proves long lasting, it could pave the way for a new and commercially attractive method for storing renewable energy.

"This is an amazing material," said Bo Zhang, a visiting researcher from the East China University of Science and Technology in Shanghai and the lead author on a paper describing the material, published online Wednesday by the journal Science.

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The key element in the process proved to be tungsten, a relatively cheap and abundant metal. The tungsten doesn't split the water itself, but its presence in the catalyst changes the properties of the other ingredients, specifically an iron-cobalt oxide, enabling it to split water more easily.

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The new material could improve the situation significantly, by making hydrogen more viable as an energy-storage option. It is one of the first tangible results to come from a research program Dr. Sargent leads in bio-inspired energy that is sponsored by the Canadian Institute for Advanced Research (CIFAR).

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The catalyst required more than a year of development during which the team started with the idea, based on earlier research, that a tungsten-infused material might yield good results. What followed was a series of steady improvements guided by theoretical predictions of how water would interact with different versions of the material.

Through the CIFAR program, Dr. Sargent was able to enlist colleagues at Stanford University who performed the theoretical work. The microscopic behaviour of the material was studied by bombarding it with a beam of high-energy X-rays at the Canadian Light Source in Saskatoon and another facility in China. A particle accelerator in the U.S. was used to verify the material's structure at atomic scales.

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Dr. Sargent said that so far the material had shown no sign of degrading after 500 hours of testing and he was optimistic that it would be robust enough to last for years.

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Katare wrote:Wacky!

nandakumar wrote:Here is a thought. Is it possible that every municipal water storage overhead tank be supplemented with a underground sump that draws power from a solar PV farm close by? Excess solar power generation can be used to pump water up and when extra power is required drain the water back to the sump via a turbine or push it into the municipal water supply mains. This has the ingredients of a pumped storage scheme. Sort of 1000s of Kadamparai pumped storage that TNEB is operating.

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A new EU-funded research project is now aiming to increase operating temperatures to up to 2,000°C by introducing compact energy storage devices based on molten silicon and solid-state heat to power converters.

The ‘Amadeus’ project, led by the Technical University of Madrid (UPM) Solar Energy Institute, could increase storage energy density over 10-fold compared with molten salt systems, Alejandro Datas, UPM research scientist, told New Energy Update.

Ultra-high temperatures will shift the heat transfer process from conduction or convection, to radiation (shining), Datas said.

“Thus, we can eliminate heat transfer fluids, and substitute the conventional heat engines [with] simpler and cost-effective solid-state converters such as infrared-sensitive photovoltaic cells, not requiring working fluids or moving parts,” he said.

UPM researchers expect their silicon-based TES to cut project capital expenditure (capex) as it is smaller, uses fewer materials and requires less labor to install, than current designs.

Silicon and silicon-based alloy materials are expected to cost below five euros/kWhth ($5.9/kWhth) while the estimated of cost of the thermophotovoltaic converter is below 1 euro/Watt, Datas said.

“We also expect lower maintenance costs, mainly due to the absence of heat transfer fluid and moving parts, he said.

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The project will focus on silicon and silicon-boron alloys as storage materials. Silicon has a latent heat level (energy required to change the state) of 1,230 kWh/m3 while silicon-boron alloys measure some 2,680 kWh/m3, Datas noted.

“These are the highest energy densities among all the current energy storage options, only surpassed by liquid hydrogen and other kinds of fuels such as gasoline,” he said.

Silicon is also the second most abundant element in the Earth’s crust, costing less than $2/kg.

One main challenge for the researchers is developing phase change materials that limit the volumetric expansion upon solidification, a characteristic of pure silicon.

The researchers have found that when used in small amounts, boron enhances the features of silicon by minimizing volumetric expansion, increasing the latent heat and reducing the melting point, Datas said.

Storage systems using 50 liters of silicon can store the same amount of heat as 500 liters of molten salts, he said.

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Design for system that provides solar- or wind-generated power on demand should be cheaper than other leading options.

Jennifer Chu | MIT News Office
December 5, 2018


MIT engineers have come up with a conceptual design for a system to store renewable energy, such as solar and wind power, and deliver that energy back into an electric grid on demand. The system may be designed to power a small city not just when the sun is up or the wind is high, but around the clock.

The new design stores heat generated by excess electricity from solar or wind power in large tanks of white-hot molten silicon, and then converts the light from the glowing metal back into electricity when it’s needed. The researchers estimate that such a system would be vastly more affordable than lithium-ion batteries, which have been proposed as a viable, though expensive, method to store renewable energy. They also estimate that the system would cost about half as much as pumped hydroelectric storage — the cheapest form of grid-scale energy storage to date.

“Even if we wanted to run the grid on renewables right now we couldn’t, because you’d need fossil-fueled turbines to make up for the fact that the renewable supply cannot be dispatched on demand,” says Asegun Henry, the Robert N. Noyce Career Development Associate Professor in the Department of Mechanical Engineering. “We’re developing a new technology that, if successful, would solve this most important and critical problem in energy and climate change, namely, the storage problem.”

Henry and his colleagues have published their design today in the journal Energy and Environmental Science.


The new storage system stems from a project in which the researchers looked for ways to increase the efficiency of a form of renewable energy known as concentrated solar power. Unlike conventional solar plants that use solar panels to convert light directly into electricity, concentrated solar power requires vast fields of huge mirrors that concentrate sunlight onto a central tower, where the light is converted into heat that is eventually turned into electricity.

“The reason that technology is interesting is, once you do this process of focusing the light to get heat, you can store heat much more cheaply than you can store electricity,” Henry notes.

Concentrated solar plants store solar heat in large tanks filled with molten salt, which is heated to high temperatures of about 1,000 degrees Fahrenheit. When electricity is needed, the hot salt is pumped through a heat exchanger, which transfers the salt’s heat into steam. A turbine then turns that steam into electricity.

“This technology has been around for a while, but the thinking has been that its cost will never get low enough to compete with natural gas,” Henry says. “So there was a push to operate at much higher temperatures, so you could use a more efficient heat engine and get the cost down.”

However, if operators were to heat the salt much beyond current temperatures, the salt would corrode the stainless steel tanks in which it’s stored. So Henry’s team looked for a medium other than salt that might store heat at much higher temperatures. They initially proposed a liquid metal and eventually settled on silicon — the most abundant metal on Earth, which can withstand incredibly high temperatures of over 4,000 degrees Fahrenheit.

Last year, the team developed a pump that could withstand such blistering heat, and could conceivably pump liquid silicon through a renewable storage system. The pump has the highest heat tolerance on record — a feat that is noted in “The Guiness Book of World Records.” Since that development, the team has been designing an energy storage system that could incorporate such a high-temperature pump.

“Sun in a box”

Now, the researchers have outlined their concept for a new renewable energy storage system, which they call TEGS-MPV, for Thermal Energy Grid Storage-Multi-Junction Photovoltaics. Instead of using fields of mirrors and a central tower to concentrate heat, they propose converting electricity generated by any renewable source, such as sunlight or wind, into thermal energy, via joule heating — a process by which an electric current passes through a heating element.

The system could be paired with existing renewable energy systems, such as solar cells, to capture excess electricity during the day and store it for later use. Consider, for instance, a small town in Arizona that gets a portion of its electricity from a solar plant.

“Say everybody’s going home from work, turning on their air conditioners, and the sun is going down, but it’s still hot,” Henry says. “At that point, the photovoltaics are not going to have much output, so you’d have to have stored some of the energy from earlier in the day, like when the sun was at noon. That excess electricity could be routed to the storage system we’ve invented here.”

The system would consist of a large, heavily insulated, 10-meter-wide tank made from graphite and filled with liquid silicon, kept at a “cold” temperature of almost 3,500 degrees Fahrenheit. A bank of tubes, exposed to heating elements, then connects this cold tank to a second, “hot” tank. When electricity from the town’s solar cells comes into the system, this energy is converted to heat in the heating elements. Meanwhile, liquid silicon is pumped out of the cold tank and further heats up as it passes through the bank of tubes exposed to the heating elements, and into the hot tank, where the thermal energy is now stored at a much higher temperature of about 4,300 F.

When electricity is needed, say, after the sun has set, the hot liquid silicon — so hot that it’s glowing white — is pumped through an array of tubes that emit that light. Specialized solar cells, known as multijunction photovoltaics, then turn that light into electricity, which can be supplied to the town’s grid. The now-cooled silicon can be pumped back into the cold tank until the next round of storage — acting effectively as a large rechargeable battery.

“One of the affectionate names people have started calling our concept, is ‘sun in a box,’ which was coined by my colleague Shannon Yee at Georgia Tech,” Henry says. “It’s basically an extremely intense light source that’s all contained in a box that traps the heat.”

A storage key

Henry says the system would require tanks thick and strong enough to insulate the molten liquid within.

“The stuff is glowing white hot on the inside, but what you touch on the outside should be room temperature,” Henry says.

He has proposed that the tanks be made out of graphite. But there are concerns that silicon, at such high temperatures, would react with graphite to produce silicon carbide, which could corrode the tank.

To test this possibility, the team fabricated a miniature graphite tank and filled it with liquid silicon. When the liquid was kept at 3,600 F for about 60 minutes, silicon carbide did form, but instead of corroding the tank, it created a thin, protective liner.

“It sticks to the graphite and forms a protective layer, preventing further reaction,” Henry says. “So you can build this tank out of graphite and it won’t get corroded by the silicon.”

The group also found a way around another challenge: As the system’s tanks would have to be very large, it would be impossible to build them from a single piece of graphite. If they were instead made from multiple pieces, these would have to be sealed in such a way to prevent the molten liquid from leaking out. In their paper, the researchers demonstrated that they could prevent any leaks by screwing pieces of graphite together with carbon fiber bolts and sealing them with grafoil — flexible graphite that acts as a high-temperature sealant.

The researchers estimate that a single storage system could enable a small city of about 100,000 homes to be powered entirely by renewable energy.

“Innovation in energy storage is having a moment right now,” says Addison Stark, associate director for energy innovation at the Bipartisan Policy Center, and staff director for the American Energy Innovation Council. “Energy technologists recognize the imperative to have low-cost, high-efficiency storage options available to balance out nondispatchable generation technologies on the grid. As such, there are many great ideas coming to the fore right now. In this case, the development of a solid-state power block coupled with incredibly high storage temperatures pushes the boundaries of what’s possible.”

Henry emphasizes that the system’s design is geographically unlimited, meaning that it can be sited anywhere, regardless of a location’s landscape. This is in contrast to pumped hydroelectric — currently the cheapest form of energy storage, which requires locations that can accommodate large waterfalls and dams, in order to store energy from falling water.

“This is geographically unlimited, and is cheaper than pumped hydro, which is very exciting,” Henry says. “In theory, this is the linchpin to enabling renewable energy to power the entire grid.”

..The researchers estimate that such a system would be vastly more affordable than lithium-ion batteries, which have been proposed as a viable, though expensive, method to store renewable energy. They also estimate that the system would cost about half as much as pumped hydroelectric storage — the cheapest form of grid-scale energy storage to date...

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However, the 2G-ethanol alcohol production technologies have struggled world-wide to be economically and technologically viable despite more than 100 pilot plants and about 10 demonstration and commercial plants erected and commissioned globally over the last decade. In this context, the country’s first demonstration plant built on the DBT-ICT indigenous technology as a continuous automated plant assumes considerable significance. The technology and the plant, projected to be capable of converting any biomass feedstock like wheat straw, rice straw, bagasse, cotton stalk, bamboo, etc. to alcohol in less than 24 hours, if successfully operated and scaled-up will establish India as a major global technology provider in the arena of renewables and reduction in carbon-emissions besides effecting considerable savings in import of crude-oil. The demo-plant is all set to run at a capacity of 10 ton biomass/day. The DBT-ICT Centre has already developed designs of plants for 250 ton/day and 500 ton/day capacities. The Department of Biotechnology is confident that this technology with the lowest capital and operating costs would allow 2G-alcohol to be produced and sold at competitive price.

Gyan wrote:Coupled with PV Solar, one needs anything upto 12-18 hours of electricity battery storage. But coupled with large off shore wind turbines, the requirements of battery storage may be reduced to 3-4 hours to maintain 24 hours availability. Off course this has to be coupled with efficient transmission network & multi site wind farms.

The relatively constant flow of ocean currents carries large amounts of water across the earth’s oceans. Technologies are being developed so that energy that can be extracted from ocean currents and converted to usable power.

Ocean waters are constantly on the move. Ocean currents flow in complex patterns affected by wind, water salinity, temperature, topography of the ocean floor, and the earth's rotation. Most ocean currents are driven by wind and solar heating of surface waters near the equator, while some currents result from density and salinity variations of the water column. Ocean currents are relatively constant and flow in one direction, in contrast to tidal currents along the shore.

While ocean currents move slowly relative to typical wind speeds, they carry a great deal of energy because of the density of water. Water is more than 800 times denser than air. So for the same surface area, water moving 12 miles per hour exerts the same amount of force as a constant 110 mph wind. Because of this physical property, ocean currents contain an enormous amount of energy that can be captured and converted to a usable form.

Strong ocean currents are generated from a combination of temperature, wind, salinity, bathymetry, and the rotation of the earth. The sun acts as the primary driving force, causing winds and temperature differences. Because ocean currents are fairly constant in both speed and flow and carry large amounts of energy, the ocean may provide a variety of suitable locations for deploying energy extraction devices such as turbines.

Ocean currents are instrumental in determining the climate in many regions around the world. While little is known about the effects of removing current energy, the impact on the farfield environment may be a significant environmental concern. Additional concerns are similar to that of tidal energy turbines. There is concern about collision between turbine blades and marine organisms due to natural animal movements, attraction to the device, or inability to avoid the turbines within strong currents. It should be noted that these turbines spin much slower than propellers on ships. There is also concern that noise from the turbines can effect animals that use sound for communication, social interaction, orientation, predation, and evasion. As with all electricity generation, electromagnetic fields generated by power cables and moving parts may effect animals that use Earth's natural magnetic field for orientation, navigation, and hunting. Likewise, chemicals such as anti-corrosion paint and small amounts of oil and grease may enter the waterbody during spills, though some turbine designs do not require lubrication.

Concerns over developing transmission infrastructure, tariff costs remain
The State-run Solar Energy Corporation of India (SECI) is likely to conduct a follow-up meeting with solar industry representatives today to discuss the details of its tender for 7.5-GW solar energy projects in Leh and Ladakh region of Jammu & Kashmir.

The tender, which is part of the government’s ambitious plan to build 23-GW solar power projects in Ladakh, had been issued by SECI on December 31, 2018 with last date set for April 30.

As per the Request for Selection (RfS) document, two solar power projects will be built in the Phase-1 — a 2.5-GW project in the Zangla region of Kargil and a 5-GW project in the Pang region of Leh.

Transmission infra
The developers will have to set up the solar generating capacities and the transmission network up to the interconnection point, at their own cost, in a span of 54 months. SECI will sign a 35-year power purchase agreement (PPA) with the project developers.

The first meeting with developers was conducted in February. However, given the size of the projects and complexity of the region, SECI has decided to conduct another meeting to clarify the details of the tender, a SECI official told BusinessLine. According to several industry players who are considering bidding for the projects, there are presently concerns over the requirement to develop the transmission infrastructure. This, coupled with logistical, geographic and security challenges typical for the region would lead to power tariff crossing ₹5 per unit.

“It is a big question whether the discoms who eventually have to buy power from these projects will be willing to buy power at this cost,” one of the industry players said.

Tariff costs
According to SECI official, since transmission infrastructure cost contributes around half of the total project cost, developers would need to achieve higher generation from their power projects as well as higher utilisation of transmission lines to make the tariff competitive.

Even then, SECI expects the tariff discovered from these projects to be 50 per cent higher than the average solar tariff. “We are anticipating the tariff of ₹5 per unit, but it could also be cheaper,” the SECI official noted. In the auctions conducted in February SECI have discovered tariffs ranging from ₹2.55 to ₹2.61 per unit.

“In theory, setting up large projects in Ladakh is a very good idea as the region has high irradiation, low temperatures and huge swathes of surplus land. The problem is on the operational and tender design fronts,” said Vinay Rustagi, Managing Director of solar consulting firm Bridge to India.

According to him, putting up dedicated transmission lines to transmit power generated by the solar plants would raise both the time and capital cost for these projects. “SECI has kept the minimum bid size at 2,500 MW and bundled transmission along with it, which we feel is highly restrictive as very few developers have the necessary operational and financial strength,” Rustagi added.