Renewable Sources of Energy

[KL Dubey]

Is there any data over time on actual yield vs installed capacity of wind farms in India?

Recent European data has been quite disappointing, with actual yields around 21% of installed capacity, despite locating the mills along North Atlantic coast and offshore which are usually quite windy.

Same in India - about 20%. USA 31%.

[nandakumar]

https://newatlas.com/energy/touchwind-f ... d-turbine/
I didn't quite understand the technical aspects of the discussion. But to my limited understanding the technology can be broken into 3 parts.
1. Submarine power cables. This is eminently doable.
2. Grouting a concrete bed on the ocean floor on which the tower would stand. This too doesn't seem a big challenge.
3. Single blade turbine. Not sure why this would be a challenge.
Can others weigh in?
Thanks.

[R Charan]

How India Plans To Use Nuclear Energy To Achieve Net Zero Emissions
https://www.defencenews.in/2023/09/how- ... emissions/

[NRao]

[R Charan]

India Launches a Project to Generate Green Hydrogen Through Nuclear Power

The Department of Atomic Energy (DAE) is starting a novel project to convert two experimental reactors into nuclear power pilot plants that will produce green hydrogen.

This massive initiative intends to show off nuclear technology's adaptability and agility while also advancing India's aspirations for sustainable energy.

The Indian High-Temperature Reactor (IHTR), created by the Bhabha Atomic Research Centre in the middle of the 2000s, is one of the reactors that is the focus of this transition.

https://defence.in/threads/india-launch ... ower.1494/

[Cain Marko]

Has anyone looked into the work of toroidal plasma generators for increasing efficiency and reducing emissions?

It seems the Indian govt and the Navy is possibly interested in this tech that can be retrofitted to regular fossil fuel fired engines but only emits about 20% oxygen and zero carbon.

Based on something called a Vajra/thunder storm generator (smart) developed and tested by an Aussie on a Perkins generator (400kw) somewhere in the UK.
https://www.alpha-prospects.com/

[rrao]

seems all Tesla electric cars are lying around charging stations as the super charger at the stations are not working due to double digit minus temperatures in the USA. so musk has got some homework to do..

[Jay]

seems all Tesla electric cars are lying around charging stations as the super charger at the stations are not working due to double digit minus temperatures in the USA. so musk has got some homework to do..

As someone who lives in this area with one of musks car, this incident is a "nothingburger" and as usual a gross exaggeration by the media.

[sohamn]

As someone owning a tesla and living in northern part of USA, this is a fake news and nothing like this has happened. Don't trust the right or the left in usa, its fake news everywhere.

[morem]

+1 , I live in colorado and own a tesla, this is a nothingburger. A lot of this is legacy auto trying to make Tesla look bad.

[Mort Walker]

This is the data from the Central Electricity Authority. Thermal, primarily from coal, and some from natural gas, remains the primary source for power generation. To get a clear picture of energy consumption, this forum needs to have an active thread on fossil fuels - even though it isn't sexy.
https://cea.nic.in/dashboard/?lang=en




Coal consumption has been increasing in the last 2 years after Covid (Apr-Jun 2022 is an aberration):

[Cyrano]

Thanks Mort ji

The units used in the graphs BUs and MUs is very telling... !

Net Zero gaya "tale" leney

If a country like India which is close to the equator can't generate meaningful solar power, imagine EU countries wallowing in energy transition delusion!

BTW, IMO renewable energy is anything but. Solar panels, wind turbines cost huge amount of resources to produce and don't turn into mushy compost at the end of their useful life.

[Mort Walker]

Solar power has a place. It is to provide the peak demand when nuclear and coal provide the base load. That is the only way it becomes a cost competitive solution. Wind power is okay, but it ruins undisturbed landscapes and adversely affects wild life including birds. Unlike North America, the Indian subcontinent doesn't have large areas of wasteland. Eventually, coal will have to be replaced with natural gas then transition to nuclear. This ins't going to happen before 2040. Until then koyla is king!

[Hriday]

https://m.economictimes.com/news/intern ... 309277.cms

Another Three Gorges Dam above Earth? China plans to build an enormous 1-kilometer-wide solar power station in space that will beam continuous energy back to Earth.

A massive solar array that China intends to install in space has the potential to generate more energy in a year than all the oil on Earth. Chinese scientists have revealed plans to construct a massive solar power plant in space that will use microwaves to continuously send energy back to Earth.
.....
Despite recent advances in solar power's cheapness and efficiency, the technology still faces limitations such as intermittent cloud cover and most of the atmosphere absorbing solar radiation before it hits the ground.

China is not the only nation eyeing plans for solar satellite arrays. U.S. companies Lockheed Martin and Northrop Grumman, the European Space Agency, and Japan's JAXA space agencies have also been investigating the technology, with the latter scheduling the launch of a small, proof-of-concept satellite this year to assess its feasibility.

From Grok AI.

Completion of this ambitious project is slated for 2035, coinciding with China's plans for a lunar research base, showcasing a strategic integration of space exploration with energy innovation.

Looks too wild and impossible.

[Amber G.]

^^^
China's plan to build a 1-kilometer-wide solar power station in space is an incredibly ambitious project. The Space-Based Solar Power (SBSP) concept isn't new, but China's proposal is one of the most significant attempts to make SBSP a reality.

While the idea is promising, there are numerous challenges to overcome. Apart from launching and assembling such a massive structure in space, and developing efficient and reliable energy transmission systems, the main concern is ensuring the safety of people and electronics on Earth from the transmitted energy.

Interestingly, India has expressed interest in collaborating with China on SBSP projects at one time (about many years ago) Although details are scarce, ISRO has bee pursuing similar plans and
exploringSBSP for several decades. In 1987, ISRO initiated studies on advanced space transportation system design concepts for cost-effective space solar power. APJ Abdul Kalam launched the Kalam-NSS Energy Initiative with the US-based National Space Society .

In the US, NASA has been exploring SBSP concepts since the 1970s. The Space Solar Power Exploratory Research and Technology program (SERT) is currently investigating this area. Similarly, Japan and Russia have similar plans in the works. (Japan demonstrated wireless power transmission about a decade ago)

One of my former students, a physics PhD, was offered a position at a startup company involved in SBSP research. They're exploring the use of lasers instead of microwaves. However, I'm skeptical about its practicality in the near future, particularly considering safety concerns, such as planes potentially flying through the beam path.

[Aldonkar]

^^^
China's plan to build a 1-kilometer-wide solar power station in space is an incredibly ambitious project. The Space-Based Solar Power (SBSP) concept isn't new, but China's proposal is one of the most significant attempts to make SBSP a reality.

While the idea is promising, there are numerous challenges to overcome. Apart from launching and assembling such a massive structure .....
However, I'm skeptical about its practicality in the near future, particularly considering safety concerns, such as planes potentially flying through the beam path.

I too have thought of such a system. My nightmare scenario would be that the remote solar cells somehow loose the connection to the Ground station (sunspots , aircraft/satellite interference etc) and the loose end drifts into a populated area. What are the consequences..

How does one prevent this.

[Amber G.]

^^^

^^^
China's plan to build a 1-kilometer-wide solar power station in space is an incredibly ambitious project. The Space-Based Solar Power (SBSP) concept isn't new, but China's proposal is one of the most significant attempts to make SBSP a reality.

While the idea is promising, there are numerous challenges to overcome. Apart from launching and assembling such a massive structure .....
However, I'm skeptical about its practicality in the near future, particularly considering safety concerns, such as planes potentially flying through the beam path.

I too have thought of such a system. My nightmare scenario would be that the remote solar cells somehow loose the connection to the Ground station (sunspots , aircraft/satellite interference etc) and the loose end drifts into a populated area. What are the consequences..

How does one prevent this.

Valid point about the potential risks! In SBSP, energy is collected in space and transmitted to the ground via microwaves or lasers. (Thus loosing the connection to the Ground station is not a big deal - you transmit only when everything is okay)

Microwaves offer higher efficiency but raise concerns about radio frequency interference and safety. Lasers provide a narrower beam but pose challenges in terms of accuracy and atmospheric interference.

Researchers have demonstrated beam widths as narrow as 1-2 kilometers at an altitude of 36,000 km (e.g., Japan's 2015 experiment). However, as you mentioned, there's still a risk of planes or birds accidentally flying into the beam path. The need for robust safety protocols and precise beam control systems to mitigate such risks.

( I find some what amusing - My kids played classic video game SimCity ( about 30 years ago!) In the game, 'microwave power plants' could sometimes cause such accidents, while nuclear power plants risked radiation leaks after riots. It's amusing to see how science fiction and gaming can sometimes foreshadow real-world technological advancements and challenges. /smile/)

[Hriday]

From the Department of Atomic Energy Twitter handle,
https://x.com/DAEIndia/status/189676186 ... cszMQ&s=19

Heavy Water Board #HWB, in collaboration with #BARC, starts construction of a demo plant for hydrogen production using the Iodine-Sulphur (I-S) process at #RCF Mumbai. The cutting-edge technology coupled with nuclear energy offers a clean and scalable hydrogen solution! 1/2

A step towards energy independence and a low-carbon future: The groundbreaking ceremony for the first-of-its-kind I-S process hydrogen plant was held on March 3, 2025 in the august presence of Secretary, DAE & Chairman, AEC; Director, BARC; Chairman & CE, HWB; and CMD, RCF. 2/2

I tried their website with the keyword hydrogen, to know more, but it is too slow or stuck. I can't find anything related on a quick search on the website either.
Adding a screenshot put by Prasad on Twitter,
https://x.com/PrasadSatya10/status/1896 ... NAGLA&s=19



In the second screenshot from Prasad, it says the technology enables large-scale production of hydrogen from water, thus giving India energy security, a step towards a hydrogen economy, net-zero targets of the Indian govt.

I remember reading that there is a suggestion to mix hydrogen into the planned nationwide natural gas pipeline. Since hydrogen storage is expensive, a piped gas network will solve that issue.

Now, can anyone explain how viable this technology is? I wish DAE bothered to put an approximate estimate of the cost involved in the process. Something like the cost per unit of electricity.

[Hriday]

^^
Could be related to the above post.
https://x.com/nitin_gadkari/status/1896 ... gVFFw&s=19

Flagging off 3 hydrogen-powered vehicles developed by @TataMotors and @IndianOilcl, along with Union Minister Shri @JoshiPralhad Ji, in Delhi today. These vehicles will operate in the Faridabad-Delhi NCR and Ahmedabad–Surat–Vadodara corridors for the next 18 to 24 months, with IOCL serving as the fuel partner for this pioneering trial.

Under the National Green Hydrogen Mission, India aims to produce 5 million metric tonnes of green hydrogen annually by 2030, reducing fossil fuel imports by ₹1 lakh crore and CO₂ emissions by 50 million metric tonnes. With ₹8 lakh crore investment, it will create 6 lakh jobs.

I think that the significance of the above plan is that BJP govt will get nearly 1 lakh crore extra by avoiding imports and they can use it to boost defence or for rural freebies to comfortably win the national elections in 2029. Is that correct?

[Cyrano]

How exactly is "green" hydrogen produced? There have been show piece hydrogen vehicles since decades. What is the technology break through that will make it a scalable mass mobility option today? Please educate me.

[durairaaj]

Green hydrogen means hydrogen generated from renewable energy with no carbon fuel as intermediate. It essentially means solar/wind/tidal energy to electricity to water hydrolysis to hydrogen.
However, the well to wheel efficiency of hydrogen as fuel is insanely poor, almost closer to internal combustion engine which is 9%.

To give you more numbers on how GREEN green hydrogen is:
1kg of H2 equals to 1 gallon (3.6 L) of gasoline / petrol as fuel in fuel cell.
To generate 1 kg of H2 it requires 25 kWh of electricity theoretically. However in reality best method consumes at least 35~45 kWh.
if you assume 4L of petrol may take your car to 60 kms, 30 kWh of energy stored in Lithium ion battery can take the car to ~300 km. In reality, green is not efficient in fuel just as it is not peaceful in faith.

The role of green H2 is in making fertilizers (ammonia to Urea) - Presently, we rely on natural gas producing countries. With green hydrogen our reliance on urea import will come down.
With green hydrogen we can upgrade low value carbonaceous crude (bottom of the barrel) to better value alkenes, naphtha, etc.
Hope it is understandable.

[Cyrano]

Yes it is, thank you. I especially liked the

In reality, green is not efficient in fuel just as it is not peaceful in faith.

part

[Amber G.]

How exactly is "green" hydrogen produced? There have been show piece hydrogen vehicles since decades. What is the technology break through that will make it a scalable mass mobility option today? Please educate me.

Green hydrogen is gaining traction because renewable energy is getting cheaper, governments are investing heavily, and major industries see it as the future—whether skeptics like it or not.

Green hydrogen is produced through electrolysis, where electricity (ideally from renewable sources) splits water into hydrogen and oxygen, emitting no CO₂. The key breakthrough making it more scalable today is plummeting renewable energy costs, improved electrolyzer efficiency, and government incentives accelerating infrastructure development. However, challenges remain, including high energy requirements, storage difficulties, and lack of refueling infrastructure. A good starting reference is the IEA’s Global Hydrogen Review (https://www.iea.org/reports/global-hydrogen-review-2023).

[KL Dubey]

How exactly is "green" hydrogen produced? There have been show piece hydrogen vehicles since decades. What is the technology break through that will make it a scalable mass mobility option today? Please educate me.

Green hydrogen is gaining traction because renewable energy is getting cheaper, governments are investing heavily, and major industries see it as the future—whether skeptics like it or not.

Green hydrogen is produced through electrolysis, where electricity (ideally from renewable sources) splits water into hydrogen and oxygen, emitting no CO₂. The key breakthrough making it more scalable today is plummeting renewable energy costs, improved electrolyzer efficiency, and government incentives accelerating infrastructure development. However, challenges remain, including high energy requirements, storage difficulties, and lack of refueling infrastructure. A good starting reference is the IEA’s Global Hydrogen Review (https://www.iea.org/reports/global-hydrogen-review-2023).

Yes.

Hydrogen has many uses.

Much of the "green" (and potentially "pink") hydrogen will go towards industrial use (e.g. chemical, steel, cement production), replacing other hydrogen types (grey, blue, etc) obtained from fossil sources.

Some of it will be used as an energy carrier for power generation/utilities.

Only a part of it will be used as transportation fuel for sectors that are hard to electrify with batteries, e.g. ships, truck fleets, etc - not necessarily small passenger vehicles. Hydrogen can be used for mobility with internal combustion engines (modification is not hard) and fuel cells.

Currently "grey" hydrogen price from fossil sources (i.e. steam methane reforming) is about $2.5-$3/kg. Adding on carbon capture and storage, i.e. "blue" hydrogen, is around $3.5/kg. "Green" hydrogen from electrolyzers is currently > $5/kg commercially, but the price is fast dropping due to breakthrough advancements in electrolyzer components. Other external factors like low renewable energy prices and govt incentives also help a lot.

[Cyrano]

Thanks folks, are there underground reserves of hydrogen that can be exploited like natural gas? Is anyone doing this already?

[Vayutuvan]

How exactly is "green" hydrogen produced? There have been show piece hydrogen vehicles since decades. What is the technology break through that will make it a scalable mass mobility option today? Please educate me.

One source is biomethane. But the process of CH4 to H is not well developed. The other is to use CH4 in a fuel cell which will produce H on the fly to fuel an ICE.

As for electrolysis, one friend who has 125+ patents in gas separation and built several plants for a large oil company, told me that that H is the most expensive H one can get.

[Amber G.]

Green hydrogen is gaining traction because renewable energy is getting cheaper, governments are investing heavily, and major industries see it as the future—whether skeptics like it or not.

Green hydrogen is produced through electrolysis, where electricity (ideally from renewable sources) splits water into hydrogen and oxygen, emitting no CO₂. The key breakthrough making it more scalable today is plummeting renewable energy costs, improved electrolyzer efficiency, and government incentives accelerating infrastructure development. However, challenges remain, including high energy requirements, storage difficulties, and lack of refueling infrastructure. A good starting reference is the IEA’s Global Hydrogen Review (https://www.iea.org/reports/global-hydrogen-review-2023).

Yes.

Hydrogen has many uses.

Much of the "green" (and potentially "pink") hydrogen will go towards industrial use (e.g. chemical, steel, cement production), replacing other hydrogen types (grey, blue, etc) obtained from fossil sources.

Some of it will be used as an energy carrier for power generation/utilities.

Only a part of it will be used as transportation fuel for sectors that are hard to electrify with batteries, e.g. ships, truck fleets, etc - not necessarily small passenger vehicles. Hydrogen can be used for mobility with internal combustion engines (modification is not hard) and fuel cells.

Currently "grey" hydrogen price from fossil sources (i.e. steam methane reforming) is about $2.5-$3/kg. Adding on carbon capture and storage, i.e. "blue" hydrogen, is around $3.5/kg. "Green" hydrogen from electrolyzers is currently > $5/kg commercially, but the price is fast dropping due to breakthrough advancements in electrolyzer components. Other external factors like low renewable energy prices and govt incentives also help a lot.

Very good response...a well-rounded perspective on hydrogen’s various applications, clarified the distinction between different types of hydrogen, and offered relevant cost comparisons. It also reinforced the idea that while green hydrogen is advancing, its primary use may not be in small passenger vehicles but in industries and sectors that are harder to electrify... Thanks.

[Amber G.]

Thanks folks, are there underground reserves of hydrogen that can be exploited like natural gas? Is anyone doing this already?

Yes, there are underground natural hydrogen reserves, often called "geologic hydrogen" or "white hydrogen." Some companies and researchers are exploring its potential, with early discoveries in places like Mali, France, and the U.S. If commercially viable this will be important.

[Amber G.]

How exactly is "green" hydrogen produced? There have been show piece hydrogen vehicles since decades. What is the technology break through that will make it a scalable mass mobility option today? Please educate me.

One source is biomethane. But the process of CH4 to H is not well developed. The other is to use CH4 in a fuel cell which will produce H on the fly to fuel an ICE.

As for electrolysis, one friend who has 125+ patents in gas separation and built several plants for a large oil company, told me that that H is the most expensive H one can get.

FWIW: My take :

The above response contains some inaccuracies and lacks key context. While biomethane can be a source of hydrogen (typically through steam methane reforming with carbon capture), it is not considered "green" hydrogen unless the CO₂ is fully mitigated. Additionally, using methane (CH₄) in a fuel cell to produce hydrogen "on the fly" is not a standard approach for scalable hydrogen mobility.

Electrolysis, despite historically being expensive, is becoming more viable due to dropping renewable energy costs and advancements in electrolyzer technology. The statement about electrolysis being the most expensive hydrogen source is outdated, as green hydrogen costs are rapidly declining with government incentives and technological improvements.

[Vayutuvan]

While biomethane can be a source of hydrogen (typically through steam methane reforming with carbon capture), it is not considered "green" hydrogen unless the CO₂ is fully mitigated. Additionally, using methane (CH₄) in a fuel cell to produce hydrogen "on the fly" is not a standard approach for scalable hydrogen mobility.

Electrolysis, despite historically being expensive, is becoming more viable due to dropping renewable energy costs and advancements in electrolyzer technology. The statement about electrolysis being the most expensive hydrogen source is outdated, as green hydrogen costs are rapidly declining with government incentives and technological improvements.

H via electrolysis is not gong to be competitive with Bio CH4 derived H anytime soon. CO2 can be fully captured in the steam reforming process. Our 2nd generation Biomethane process (yes, a company in which I have significant but minority interest has a patent in India on this process and US and EU patent applications are in the pipeline) is completely C neutral. CO2 is captured, sulphur is removed. Steam reforming of H from biogas has significant technological challenges. OTH, H from electrolysis is not economically feasible now and remain so for foreseeable future. Biomethane is a the bridge to go from Coal/fossil fuels --> nuclear/solar power generation --> (fully?) Green H. That is one possible path. A judicious mix of Biomethane, nuclear, solar, and Hydrogen is what the future holds.

[SriKumar]

Since electricity from renewable sources is needed to produce green Hydrogen, the options are solar, wind and hydro-electricity. Relative to oil, these sources of renewable energy generate a rather limited amount of power (there are limits to how much area can be covered with solar panels/wind turbines). Unless they use nuclear-generated electricity, it appears that Hydrogen's wide-spread usage (relative to oil) may be limited, or so it appears.

[Vayutuvan]

Unless they use nuclear-generated electricity, it appears that Hydrogen's wide-spread usage (relative to oil) may be limited, or so it appears.

Good point. From groundbreaking to bringing a nuclear power plant online has a longish lead time. You need a bridge solution right now. This is where Biomethane can help. It will be critical for the next 20 years. After that it will be one of the components in the mix of nuclear/Hydrogen/Biomethane.

The question still remains whether solar and wind are even renewable leave alone sustainable. It may not be all that "green" ones we account for cradle to cradle costs, i.e. costs (in energy terms) for recycling solar panels/windmills. Recycling efficiency matters as well. Decreasing marginal rate of efficiency vis a vis energy spent on recycling.

[Vayutuvan]

(From Wikipedia)

Solar and wind renewable energy is not sustainable at this time.

[Vayutuvan]

https://en.wikipedia.org/wiki/Sustainab ... mic_growth

Eco-economic decoupling is an idea to resolve tradeoffs between economic growth and environmental conservation. The idea is to "decouple environmental bads from economic goods as a path towards sustainability".[11] This would mean "using less resources per unit of economic output and reducing the environmental impact of any resources that are used or economic activities that are undertaken".[10]: 8  The intensity of pollutants emitted makes it possible to measure pressure on the environment. This in turn makes it possible to measure decoupling. This involves following changes in the emission intensity associated with economic output.[10] Examples of absolute long-term decoupling are rare. But some industrialized countries have decoupled GDP growth from production- and consumption-based CO2 emissions.[103] Yet, even in this example, decoupling alone is not enough. It is necessary to accompany it with "sufficiency-oriented strategies and strict enforcement of absolute reduction targets".[103]: 1 

One study in 2020 found no evidence of necessary decoupling. This was a meta-analysis of 180 scientific studies. It found that there is "no evidence of the kind of decoupling needed for ecological sustainability" and that "in the absence of robust evidence, the goal of decoupling rests partly on faith".[11] Some experts have questioned the possibilities for decoupling and thus the feasibility of green growth.

It is possible in the short term to pull off "using less resources per unit of economic output and reducing the environmental impact of any resources that are used or economic activities that are undertaken".

We see inefficiencies everywhere. A lot of can be squeezed out right now if only technologists are given free hand. But then it runs into all kinds of political bickering and backbiting. It is happening as we speak in the US considering the amount of pushback and hate Musk is getting.

[Amber G.]

Sorry for the long post .. (ignore if not interested in technical details)..

..Our 2nd generation Biomethane process (yes, a company in which I have significant but minority interest has a patent in India on this process and US and EU patent applications are in the pipeline) is completely C neutral. CO2 is captured, sulphur is removed. Steam reforming of H from biogas has significant technological challenges.

Best wishes...

OTH

H from electrolysis is not economically feasible now and remain so for foreseeable future.

IMO, The statement is [increasingly] outdated due to several key factors -

Current Costs Are High but Dropping Fast:

Today, green hydrogen from electrolysis typically costs $4–$7 per kg (compared to $2–$3 per kg for gray hydrogen (from fossil fuels)). However, as said, costs are falling due to improved electrolyzer efficiency, economies of scale, and cheaper renewable energy.

Some projections suggest sub-$2/kg green hydrogen by 2030, making it competitive with gray hydrogen.

- Government Incentives and Investments -

Many countries are heavily subsidizing green hydrogen (e.g., the U.S. Inflation Reduction Act provides up to $3/kg in tax credits).

Technological Advancements

New electrolyzer technologies (e.g., PEM, solid oxide, and AEM electrolyzers) are increasing efficiency and reducing costs.
Scaling up production and automation is expected to lower electrolyzer capital costs.
Industrial Demand and Decarbonization Goals

Heavy industries (steel, ammonia, chemicals) are shifting toward green hydrogen due to carbon reduction mandates.
Countries with excess renewable energy (e.g., Australia, Chile) are developing large-scale hydrogen projects for export.

--
Green hydrogen is still more expensive than fossil-based hydrogen today, but the trend is clear: costs are falling rapidly, and large-scale adoption is accelerating. Saying it will "remain economically unfeasible for the foreseeable future" simply ignores the momentum from technological progress, policy support, and market forces.

---

Meanwhile as few posts mentioned here in India - Using nuclear power plants for hydrogen production is a promising approach ... and India's plans to integrate hydrogen generation with nuclear energy align with global trends.

For those who do not know - India is exploring nuclear-powered hydrogen as part of its National Green Hydrogen Mission, leveraging PHWRs (and future advanced modular reactors -AMRs). If successful, it could create a domestic, low-carbon hydrogen economy while reducing reliance on fossil fuels.

To me it makes sense because:

- Nuclear plants provide a constant and reliable power supply, unlike solar or wind, which are intermittent. This ensures a steady hydrogen production rate.

High-Temperature Electrolysis (HTE) Efficiency – Nuclear reactors can support high-temperature electrolysis (HTE), which is more efficient than conventional electrolysis, requiring ~30% less electricity.

Potential for Thermochemical Hydrogen Production – Advanced nuclear reactors (e.g., high-temperature gas-cooled reactors, HTGRs) can directly produce hydrogen via thermochemical cycles like the Sulfur-Iodine (S-I) process, which bypasses electrolysis entirely and could achieve very high efficiency.
– Excess nuclear power during low electricity demand periods can be diverted to hydrogen production, improving plant utilization.

ityadi ...ityadi...

Bottom line: Using nuclear for hydrogen production, IMO, is a viable long-term solution, particularly with HTE or thermochemical methods (not to say there are challenges eg scaling up will require continued technological advancements....

[Vayutuvan]

Since Climate United Fund is in the news (for the wrong reasons, if negatively if I may add)

Here is a document which makes for an interesting read

https://weareclimateunited.org/tools-and-resources

and a pdf https://assets.ctfassets.net/urgx2rpiyy ... vFINAL.pdf

There is a lot of emphasis on EVs and Solar. Some emphasis is placed on improved "Electricity transportation" which I am assuming to be improving some parts of the power grid.

[Amber G.]

For those who have serious interest, I highly recommend - from the author of 'Physics for future Presidents -
The book - "energy for future presidents" by Richard Muller

[KL Dubey]

IMO, The statement is [increasingly] outdated due to several key factors -

Current Costs Are High but Dropping Fast:

Today, green hydrogen from electrolysis typically costs $4–$7 per kg (compared to $2–$3 per kg for gray hydrogen (from fossil fuels)). However, as said, costs are falling due to improved electrolyzer efficiency, economies of scale, and cheaper renewable energy.

Some projections suggest sub-$2/kg green hydrogen by 2030, making it competitive with gray hydrogen.

Yes. Steam methane reforming (SMR) is about $2.5/kg. A decade ago, certainly electrolysis was not competitive, but now its a different story. Costs have dropped a lot, from traditional alkaline electrolyzer ($4-5/kg) --> proton exchange membrane (PEM) electrolyzer ($3.5-4/kg) --> anion exchange membrane (AEM) electrolyzer ($2-3/kg).

Once the AEM-based processes hit $2.5/kg or so (i.e. same range as SMR), I expect adoption to accelerate, we may not need to wait for sub-$2 prices. Two major reasons:

- SMR is very cheap to operate but expensive to build (CAPEX usually > $2/kg). Water electrolysis CAPEX will be well under $1/kg, which is a major incentive for upfront investment. Electrolyzers are very modular and operationally flexible units.

- Direct water splitting is attractive to investors since there will no parasitic CO2 capture and storage costs.

[Amber G.]

^^^Thanks. Very informative..

[Amber G.]

...there are limits to how much area can be covered with solar panels/wind turbines ... Unless they use nuclear-generated electricity....

As I said more than a decade ago in nuclear dhaga (or another such dhagas) and often mention in popular physics classes, here’s a classic tidbit:

---- – A square kilometer of sunlight contains roughly the same amount of energy as a nuclear power plant (occupies the land). This means that if you were to cover a square kilometer with solar panels, you could generate a significant amount of electricity, comparable to the output of a nuclear power plant (both around 1 GW).

With current efficiency (Notice that solar panels are still not very efficient) :

- 1 GW nuclear power plant requires about 1 to 4 square kilometers (typically around 4 sq km).
- 1 GW solar farm would require around 5 square kilometers (or may be up to 20 or more), though solar panel efficiency is still improving.
Both, as physicists would say, are within the same/similar order of magnitude!