Do we finally have an alternative?

[Marvin]

News just in

 

https://sifted.eu/articles/solar-energy-breakthrough-solid-hydrogen.

 

 

[SteamyTea]

Solid Oxide Fuel Cells have been around a while in the labs.

[Marvin]

6 minutes ago, SteamyTea said:

Solid Oxide Fuel Cells have been around a while in the 

So a tried and tested technology?

[SteamyTea]

14 minutes ago, Marvin said:

So a tried and tested technology?

In the lab yes, that is how they know it works at very high temperatures.

 

From a quick read though of the article, it seems they are pretending that excess solar energy has zero value and thermal energy has a very high value.

I would think that with a bit of digging you will find they are looking to raise funding, not actually sell a product that is useful.

 

Do you remember the man that made a battery from aluminium cans a while back, I bet he has retired on the development money.

Then there were all those micro wind and water turbines that would save us.

Oh, don't forget the perovskite, that was all the rage 5 years ago.

 

Meanwhile, back in the real world the big boys have raised PV efficiency a few percent and reduced the cost another 5 fold.

[joe90]

Well I think it’s a good idea we have entrepreneurs that discover stuff, from my (non technical mind) it reads more about storage and even inter seasonal storage. Yes PV may be getting better and cheaper but that does not store energy.

[Marvin]

Hi @SteamyTeaI knew I could rely on you for a more objective view. 

 

The principle of local generation and local storage of energy is one I ascribe to. However, still using the grid.

 

As I have commented before we produce more than double the energy for all our home needs from our PV system it's just that we can't practically store the energy produced in the summer to use in the winter.

Edited October 25, 2023 by Marvin

[SteamyTea]

6 minutes ago, Marvin said:

The principle of local generation and local storage of energy is one I ascribe to. However, still using the grid.

In reality that is what already happens.  Your excess power goes to the nearest load.

What is really the issue is the billing.  We would all like to be paid for selling excess energy, but non of us what to enter into a contract what would, by necessity, penalise us is we did not supply when we had to.

The easy way around this is to have a lot more distributed generation and accept that the import unit price will either fluctuate wildly or we pay a higher fixed unit price all the time.

By higher price I do not necessarily mean higher than we currently pay, just higher than the cheapest production price.

[SteamyTea]

This was in my comic.  I knew the hydrogen had to be 'clean' to run though a fuel cell, never thought about the water that makes it.

 

Can we get limitless green hydrogen by splitting seawater?

Electrolysers that split water to produce hydrogen have trouble working with seawater, but overcoming this would offer new ways to produce the clean-burning fuel using offshore renewable energy

By James Dinneen

25 October 2023

 

 

 

Seawater could be a limitless source of hydrogen, but we need electrolysers that can handle the high salt concentration

Shutterstock/andrejs polivanovs

 

The following is an extract from our climate newsletter Fix the Planet. Sign up to receive it for free in your inbox every month.

97 per cent of the water on Earth is in the ocean. If even a small amount of that could be harnessed to make hydrogen using clean energy, it would provide a practically limitless source of clean-burning fuel that would accelerate the transition away from fossil fuels. But there’s a catch.

The devices currently used to split water molecules to make hydrogen — called electrolysers — require ultra-pure water to function. And seawater is full of dissolved salt, other minerals, metals and microorganisms that degrade components and gum up the works.

Recently, researchers have made headway on solving these problems. Some are pushing ahead with plans to make hydrogen from desalinated seawater, while others have developed new electrolyser designs that could be attached to offshore wind turbines to make hydrogen directly from the ocean.

Success here would not only reduce the demand for freshwater to make the fuel, but also expand the range of places where it makes sense to produce hydrogen.

Something in the water

Hydrogen will play an increasingly important role in decarbonising our energy systems on the way to net-zero by mid-century. The clean-burning gas can be used to store and transport energy, and it can power things that are difficult to power directly with electricity. The latest projections from the International Energy Agency see global production of low-emission hydrogen increasing rapidly, with planned projects amounting to 38 million tonnes per year by 2030.

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There are a variety of sources of low-emission hydrogen, but most of it is set to be made by splitting water molecules using renewable electricity, making what’s known as “green hydrogen”. The main limitation now on green hydrogen production is access to cheap renewable electricity. But as hydrogen production increases, access to water could also become an issue.

“We need to avoid creating a situation where there is competition between water that we need for drinking and water that we need for fuel production,” says Pau Farras at the University of Galway in Ireland. Estimates vary for how much water might be needed for hydrogen production – and some argue the problem is overstated – but Farras says producing hydrogen could eventually account for as much as 20 per cent of water use in some places, especially where there is scarce freshwater.

Using abundant seawater would avoid this problem. Splitting seawater could also enable new ways of combining offshore renewable energy with hydrogen production, expanding the geographical range of both. This possibility in particular has driven new interest in splitting seawater.

For instance, in March the Netherlands announced a plan to build a large offshore electrolyser in combination with an offshore wind farm in the North Sea. The hydrogen produced there would then be sent back to shore via an existing natural gas pipeline, avoiding the need to lay expensive new undersea transmission lines.

At least 10 other major projects combining offshore wind and hydrogen are in the works elsewhere, including several off the coast of the UK. For wind farms built more than 50 kilometres offshore, it could actually be cheaper to transport the energy they produce back to shore as hydrogen via ships or pipelines rather than as electricity via copper wires.

Researchers at the technology firm Siemens, which is investing large sums in wind-t0-hydrogen technology, even envision automated “production islands” that use seawater and offshore wind energy to continuously make hydrogen and other chemicals like ammonia to refuel ships sailing by.

Stripping salt

A big problem for these futuristic visions, however, is that seawater is poorly suited to the finicky chemistry of electrolysis. Even normal potable water requires extra purification steps before it can be used in a conventional electrolyser, says Alexander Cowan at the University of Liverpool in the UK. “Seawater is the extreme.”

In an electrolyser, water — H₂O — is run past two electrodes. Hydrogen atoms move to the negatively-charged cathode, while the oxygen atoms stay near the positively-charged anode and are released into the atmosphere. Normally, ultra-pure deionised water is used in this process.

Using seawater, with all its impurities, causes problems. The dissolved salts and minerals degrade many of the catalysts and other components used in the devices, so they wear out very quickly. Running electricity thought the water can also oxidise chloride to produce corrosive chlorine products. Biofouling from microbes growing in the water is another issue. “If you have a biofilm on top of the electrodes your reaction is dead,” says Farras.

 

 

A hydrogen refuelling station in Tenerife, Spain

Lucia Villalba

 

One way around these problems is to desalinate the seawater before sending it to the electrolyser. On Tenerife, one of Spain’s Canary Islands, Farras and his colleagues have installed a self-contained system that uses desalinated seawater and solar energy to make hydrogen using a conventional polymer electrolyte membrane (PEM) electrolyser. Farras says officials were interested in the project to reduce the island’s reliance on imported fossil fuels.

The system, which is the size of a 12-metre shipping container, can now produce up to 65 kilograms of hydrogen each day, which Farras says would be enough to supply two to three hydrogen fuel-cell powered buses and several cars. His team is now in conversations with Tenerife’s transport administration to fuel public buses with hydrogen next year in an effort to “kickstart” demand for hydrogen on the island.

Using desalinated seawater for hydrogen production makes sense, especially where substantial desalination capacity already exists, says Farras. The hyper-futuristic Saudi Arabian city of Neom, for instance, is supposed to include a facility that could produce 600 tonnes of green hydrogen a day using desalinated water from a plant that will also supply the city with drinking water.

Going direct

However, desalination isn’t an ideal solution. It adds to the energy requirements of making hydrogen, and may be poorly suited for smaller, more distributed systems, says Zongping Shao at Curtin University in Australia.

Another approach is to design electrolysers that can work directly with seawater, thus avoiding the need for a separate desalination step. There has been a flurry of research on how these seawater-hardy devices could work, with a variety of designs. According to Cowan, they fall into two broad categories: some involve using membranes to purify seawater before it flows through the electrolyser, and others use different components or designs that are more robust to seawater.

In one design, Shao and his colleagues sandwiched an electrolyser between special Teflon membranes and then ran seawater around the outside. The membranes enabled water vapour to diffuse into the electrolyser while leaving impure components outside. In a study published last year, this system continuously produced hydrogen using seawater in tests for at least 3200 hours without any noticeable changes in function. “That could change the calculation,” says Cowan. “If you could run something for years without much maintenance that’s interesting.”

 

Read more

Waste plastic can be recycled into hydrogen fuel and graphene

 

Another approach, taken by Daniel Nocera at Harvard University and his colleagues, similarly purifies water before it reaches the electrolyser by passing it across a membrane. As the water molecules are split on one side of the membrane, this maintains a concentration gradient that draws more water through by osmosis.

Daniel Esposito at Columbia University in New York and his colleagues have done away with membranes entirely in an effort to make cheaper, more robust electrolysers. A company he co-founded called sHYp is aiming to commercialise these membraneless electrolysers by pairing them with a proprietary saltwater processing step that produces other valuable byproducts, such as magnesium hydroxides that could be used to make carbon-negative cement.

According to the company’s CEO Carl Fischer, the processing unit works by increasing the alkalinity of the seawater before it reaches the electrolyser, which he says avoids biofouling and unwanted reactions with chlorine. He says the company has pilot projects planned for next year in the US, the UK and Europe, including plans to install the electrolysers on offshore wind turbines and at ports.

Horses for courses

Cowan says that while many of these methods of direct seawater electrolysis are promising, at scale they are likely to suffer from some of the same problems as conventional electrolysers trying to manage the complexities of seawater, such as biofouling from the ubiquitous microbes that live in the ocean.

Farras also has doubts about this approach. “You can work around these problems in the chemistry. But I don’t think you can work around the biology,” he says. “Direct seawater electrolysis is a fantasy.”

Even if the direct approach could be made to work at scale, Farras says it may be unnecessary in contexts where large-scale desalination is already available. Desalination adds to energy requirements, but only a small amount when compared to the energy demand of electrolysis itself.

However, Cowan thinks direct electrolysis could have its uses, especially for remote places where large-scale desalination might be impractical. It could also be key for the many projects aiming to integrate electrolysis with offshore energy production, opening valuable space on offshore platforms that would be taken up by a bulky desalination operation.

Further, he says research on directly using seawater could lead to more robust electrolysers in general. These could use wastewater, or simply better withstand the inevitable impurities in any water on its way to becoming fuel.

[Marvin]

Hi @SteamyTea

Thanks for that.

 

Interesting. I think one of the problems is that every type of new invention is considered as "the" solution. I'm of the opinion that all these alternatives should be used to ADD to the pile of choices not chuck everything else away.

[SteamyTea]

1 minute ago, Marvin said:

Interesting. I think one of the problems is that every type of new invention is considered as "the" solution. I'm of the opinion that all these alternatives should be used to ADD to the pile of choices not chuck everything else away.

Yes.  I blame the IT industry, everything has to be reduced to a 0 or 1, with 0 being wrong and 1 being right.

 

The main thing is to reduce usage, there was a bit about food waste in the USA, apparently a third is wasted (and they start with a lot more).

The emissions from this waste was equivalent to 55 million tonnes of CO₂.  About the same as running 12 million gasoline cars (and they are not the most economic cars in the USA).

[Marvin]

1 hour ago, SteamyTea said:

I blame the IT industry, everything has to be reduced to a 0 or 1, with 0 being wrong and 1 being right.

I never thought of it that way. A bit like USA politics....

[SteamyTea]

4 minutes ago, Marvin said:

bit like USA politics.

And ours sadly.

 

[JohnMo]

3 hours ago, SteamyTea said:

Can we get limitless green hydrogen by splitting seawater

When you take seawater and make hypochlorite, which they have been doing for decades offshore, for local injection into seawater lift, to kill of marine growth in piping systems and heat exchangers, one of the byproducts is hydrogen.

[SteamyTea]

6 minutes ago, JohnMo said:

When you take seawater and make hypochlorite, which they have been doing for decades offshore, for local injection into seawater lift, to kill of marine growth in piping systems and heat exchangers, one of the byproducts is hydrogen.

It is a big industry, a lot of 'things' need bleaching.

I wonder how my hydrogen is produced.

[Gone West]

I hadn't heard about this before but it was apparently reported last year as a possiblity, and has now been confirmed. How long it takes to naturally produce 250m tonnes of hydrogen I do not know.

 

Hydrogen has long been seen as a wonder fuel that does not give off greenhouse gases when used, and which could help replace fossil fuels. But there is at least one major drawback to this idea because the production of hydrogen largely uses fossil fuels and so making clean hydrogen from the process of splitting water needs renewable sources of electricity. Lots of power is required and it is expensive.

Less well known are deposits of natural hydrogen buried underground. Scientists at the University of Lorraine were searching for methane in north-east France, when they unexpectedly discovered a large deposit of natural hydrogen more than 1,000 metres deep underground. This hydrogen is produced by groundwater reacting with iron-rich minerals, splitting the water into hydrogen, possibly renewing itself almost indefinitely.

Natural hydrogen deposits have been found before and there is already a small well in western Mali. Larger deposits are thought to exist elsewhere, such as the US, Australia and some European countries. But the discovery in France could be the largest naturally occurring deposit of the gas ever found, possibly 250m tonnes of hydrogen, enough to meet current global demand for more than two years. The challenge is how to transport that gas to where it is needed.

[Mike]

8 hours ago, Gone West said:

Hydrogen has long been seen as a wonder fuel that does not give off greenhouse gases when used, and which could help replace fossil fuels. But there is at least one major drawback to this idea because the production of hydrogen largely uses fossil fuels... ...The challenge is how to transport that gas to where it is needed.

Distribution is indeed a problem. If it was to be used domestically the gas grid would need to be upgraded to cope with the additional pressures and gas-tightness required. Although it may have a niche role for some uses, the prospect of hydrogen in the home is at best wishful thinking by the fossil fuel industry, at worst a wilful distraction from electrification.

[Gone West]

13 hours ago, Mike said:

Distribution is indeed a problem. If it was to be used domestically the gas grid would need to be upgraded to cope with the additional pressures and gas-tightness required. Although it may have a niche role for some uses, the prospect of hydrogen in the home is at best wishful thinking by the fossil fuel industry, at worst a wilful distraction from electrification.

If it was all kept by France and not exported, then used solely for electricity generation it would surely make a useful dent in reducing France's CO2 production.

[ProDave]

24 minutes ago, Gone West said:

If it was all kept by France and not exported, then used solely for electricity generation it would surely make a useful dent in reducing France's CO2 production.

With such a large reserve, the obvious thing would be to build a large hydrogen fuelled power station close to the well head. then all the distribution is by cables.

 

Now a controversial thought.  That Hydrogen has been there a very very long time.  Burning it will remove O2 from the atmosphere and add water vapour to the atmosphere.  Has anybody modelled what that will do to the climate? 

[Mike]

9 hours ago, Gone West said:

If [hydrogen] was all kept by France and not exported, then used solely for electricity generation it would surely make a useful dent in reducing France's CO2 production.

It would, but much better to use it for uses that are difficult to electrify - producing cement, iron, steel; HGVs, shipping, aircraft, etc. So perhaps creating something like the UK's planned industrial hydrogen / CCS clusters - e.g. https://eastcoastcluster.co.uk/

 

9 hours ago, ProDave said:

Has anybody modelled what [burning hydrogen] will do to the climate?

Yes - for example https://assets.publishing.service.gov.uk/media/624eca7fe90e0729f4400b99/atmospheric-implications-of-increased-hydrogen-use.pdf

 

[SteamyTea]

7 minutes ago, Mike said:

uses that are difficult to electrify - producing cement, iron, steel

I think they can all be done without combustion, adding carbon to iron, to make steels is still a high carbon process though.

8 minutes ago, Mike said:

CCS clusters

Rather missing the point.  Why make an unnecessary mess, just to clean some of it up.

[ProDave]

13 minutes ago, Mike said:

Yes - for example https://assets.publishing.service.gov.uk/media/624eca7fe90e0729f4400b99/atmospheric-implications-of-increased-hydrogen-use.pdf

 

That looks at escape of hydrogen into the atmosphere.

 

I was considering the burning of a long time captured reserve of hydrogen would result in removal of oxygen from the atmosphere as well as release of water vapour into the atmosphere.

 

This is different to producing hydrogen as a means of "energy transportation" and then burning it. Both ends of the process pretty much cancel out.

 

A bit like the burning of recently grown wood = good, burning very old stored wood (coal) = bad.

[Temp]

16 hours ago, ProDave said:

 

I was considering the burning of a long time captured reserve of hydrogen would result in removal of oxygen from the atmosphere as well as release of water vapour into the atmosphere.

 

Isn't that what happens now when we burn coal, oil etc. 

[ProDave]

56 minutes ago, Temp said:

 

Isn't that what happens now when we burn coal, oil etc. 

Yes, which is regarded as bad for the environment.  So before rushing to burn this new massive reserve of hydrogen, would it not be a good idea to ensure this is not just going to be a different problem going forwards?

[SteamyTea]

22 minutes ago, ProDave said:

before rushing to burn this new massive reserve of hydrogen

Most hydrogen would be passed through a fuel cell, not burnt.

Combustion technologies have really poor efficiency.

Fuel cells are not that much better.

https://www.linquip.com/blog/efficiency-of-fuel-cell/

 

There is a reason they are called 'fool cells'.

[Temp]

1 hour ago, ProDave said:

Yes, which is regarded as bad for the environment.  So before rushing to burn this new massive reserve of hydrogen, would it not be a good idea to ensure this is not just going to be a different problem going forwards?

 

I think thats unlikely to be a problem. We've had a negligible effect on O2 levels in the atmosphere by burning fossil fuels.  Even the CO2 produced is only such a problem because the greenhouse effect is very sensitive to CO2 levels.

 

I'm more concerned about the effect Hydrogen has. I think Hydrogen is a greenhouse gas so the cumulative effect of leaks might be an issue.