Is reducing energy losses critical for the success of hydrogen in the gas grid?

[tech99]

TL;DR Summary

A trial has commenced at Keele Unversity in the UK where 20% Hydrogen, produced from wind and solar, is injected into the domestic gas supply. In this way it can be stored and then utilised by existing domestic burners. Can this be a quick solution to reducing domestic CO2 emissions? Or is it better to use battery storage and use the electricity?

A trial has commenced at Keele University in the UK where 20% Hydrogen is injected into the domestic gas supply. In this way it can be stored and then utilised by existing domestic burners. Can this be a quick solution to reducing domestic CO2 emissions? Or is it better to use battery storage and use the electricity? https://www.bbc.co.uk/news/science-environment-50873047
What is the best way of using wind and solar for electric cars? Is the domestic heat pump a better long term investment for home heating?

 

[mfb]

Electricity -> hydrogen isn't a very efficient process. Electricity store and electric heating would be more efficient. Heat exchangers instead of raw electric heating would make it even better. Combined you can easily win a factor 5. Is "renewables but we can't control when" really so much cheaper than electricity storage? Sure, it is better than doing nothing, but overall it doesn't look like something that is worth scaling up.

 

[pbuk]

Or is it better to use battery storage and use the electricity?

You are missing the point - there are many more efficient ways to use energy for space heating and domestic hot water, they all require time and money invested in every dwelling to use them. In order to get near to zero carbon we HAVE to invest this time and money, but it will take decades and £billions invested in individual homes as well as infrastructure to do it, whereas...

Can this be a quick solution to reducing domestic CO2 emissions?

...domestic CO2 emissions in the UK could possibly be reduced by up to 20% almost overnight using this solution.

 

[Rive]

Sure, it is better than doing nothing, but overall it doesn't look like something that is worth scaling up.

It is a very common misconception that it'll be for free if the electricity itself is cheap.

 

[BWV]

ITSM the correct cost / benefit is whether a marginal KW of electricity generated by renewables is better utilized in the grid or being converted to H to reduce emissions from the domestic burning of natgas for heat and cooking. Assume equal transmission losses, the electricity should go to the grid until it is close to 100% renewable (which will not happen for decades). The KW sent to the grid either:
A) replaces a KW generated by coal, which has around 2x the greenhouse gas emission
B) replaces a KW generated by Natgas, but with greater efficiency than using that KW to create H

Also, given a marginal dollar to invest, it would have greater impact using that dollar to provide natgas to poor countries that burn solid fuel (greater greenhouse gas emission plus a host of health benefits) than it would to replace natgas with H in rich economies

 

[pbuk]

The KW sent to the grid either:
A) [notreplaces a KW generated by coal, which has around 2x the greenhouse gas emission
B) replaces a KW generated by Natgas, but with greater efficiency than using that KW to create H

The context of the article is the UK where, as stated in the article, approximately 85% of homes are heated by natural gas which is piped to each home and used in a system something like this. How can a kW of electricity sent to the grid be used in such a system?
Edit (restated for clarity): How can a kW of electricity sent to the grid replace the kW produced by burning the gas that heats the water in such a system to heat my home?

 

[mfb]

How can a kW of electricity sent to the grid be used in such a system?

In the same way all other electricity is used in the grid.
The UK got rid of most of its coal power plants, so additional renewables will mainly replace gas. Burning gas in homes to heat them and using electricity from renewables is more efficient than burning gas to produce electricity and using renewables to produce hydrogen to burn in the houses.

 

[pbuk]

In the same way all other electricity is used in the grid.

I have edited my post as the point I was trying to make was not clear.

Burning gas in homes to heat them and using electricity from renewables is more efficient than burning gas to produce electricity and using renewables to produce hydrogen to burn in the houses.

It may be more efficient, but it also produces more CO2.
Edit: This is only true if you assume that the low-carbon energy used to produce hydrogen could have been used to reduce fossil fuel consumption. Already in the UK, at times this is not the case - and in the near future perhaps even more so.

Personally I think there are better long-term solutions than replacing natural gas with 100% hydrogen in domestic boilers, but that doesn't mean that it is not worth investigating mixing hydrogen into the domestic natural gas supply for a short-term gain.

 

[BWV]

The context of the article is the UK where, as stated in the article, approximately 85% of homes are heated by natural gas which is piped to each home and used in a system something like this. How can a kW of electricity sent to the grid be used in such a system?
Edit (restated for clarity): How can a kW of electricity sent to the grid replace the kW produced by burning the gas that heats the water in such a system to heat my home?

you seem to be missing the point that electricity generated from renewables is a finite resource. The point is that its better to use that electricity to replace electricity generated by fossil fuels in the grid before the much less efficient process of using that electricity to create H to burn for heat or cooking

 

[Vanadium 50]

Can this be a quick solution to reducing domestic CO2 emissions?

No. Apart from the excellent point that burning natural gas to create electricity to make hydrogen is less efficient than burning the natural gas at point of use, it's focusing on a tiny part of the problem.

In the US (where numbers are easily available) 12% of GHG emissions are from the commercial and residential sectors, and 89% of that is natural gas, or 10.7%. Replacing 20% of this - by magic, not by the inefficient process described above - would change US emissions by 2%, or world-wide emissions by 0.3%.

The UK is ~10x smaller, so we're talking 0.03% or so.

 

[mfb]

It may be more efficient, but it also produces more CO2.

No it doesn't.
You'll produce 1 kWh of electricity from renewables in the next hour. What do you do?
- regulate down a natural gas power plant to produce 1 kWh less. It will reduce CO2 emissions by 400 g.
- produce hydrogen with an energy content of maybe 0.3 kWh, send it to consumers. They burn it, saving a bit of natural gas in the process. You reduced CO2 emissions by 200 g (optimistic).

Once most natural gas power plants are out of business this might become more interesting as the first option won't exist any more. By that time hopefully most people switched to electric heating. Then this 1 kWh will save 400 g of CO2 again. Or, even better, switched to heat pumps, then it saves over 1 kg of CO2 emissions.

 

[pbuk]

In the US (where numbers are easily available) 12% of GHG emissions are from the commercial and residential sectors, and 89% of that is natural gas, or 10.7%. Replacing 20% of this - by magic, not by the inefficient process described above - would change US emissions by 2%, or world-wide emissions by 0.3%.

The question was not "will this have a dramatic effect on total global emissions", it was "Can this be a quick solution to reducing domestic CO2 emissions?" Let's redo your calculation: 89% of US commercial and residential emissions are from natural gas. Replacing 20% of this (assuming this can be done without creating additional emissions) could change US domestic emissions by 18%. That sounds like it's worth investigating - and even more so in the UK where the existing domestic energy infrastructure gives different challenges.

Apart from the excellent point that burning natural gas to create electricity to make hydrogen is less efficient than burning the natural gas at point of use

Of course it is, and burning coal to do it would be even worse. But if you could generate that hydrogen using surplus renewable capacity at times of low demand it wouldn't be. And even if you did burn gas to generate power for electrolysis there is the potential for carbon sequestration which is not possible when burning natural gas in a domestic boiler.

it's focusing on a tiny part of the problem.

In my experience that is how big problems are solved.

 

[Tom.G]

At least here in the USA, many (most?) gas pipes are steel. Using Hydrogen in them brings up the problem of making the steel pipes brittle, leading to fractures... and a pure Hydrogen flame is invisible! (no incandescent Carbon to generate visible light.)

https://scholar.google.com/scholar?...+in+steel&hl=en&as_sdt=0&as_vis=1&oi=scholart

Not saying it can't be done, just that there are a lot 'unmentioned circumstances.'

Cheers,
Tom

 

[pbuk]

pbuk said: It may be more efficient, but it also produces more CO2.

No it doesn't.
You'll produce 1 kWh of electricity from renewables in the next hour. What do you do?
- regulate down a natural gas power plant to produce 1 kWh less. It will reduce CO2 emissions by 400 g.
- produce hydrogen with an energy content of maybe 0.3 kWh, send it to consumers. They burn it, saving a bit of natural gas in the process. You reduced CO2 emissions by 200 g (optimistic).

OK, I understand where you are coming from. But what if the first alternative is not available because gas plants are already at minimum capacity? In the UK we already store surplus energy at times of high generation and low demand (mainly in pumped hydro), and as fickle renewable generation increases this will become a bigger issue (as I write this, wind is providing 45% of the UK's current power need because most people are in bed with the heating off and there are strong winds on our offshore wind farms).

I will edit my assertion accordingly.

Once most natural gas power plants are out of business this might become more interesting as the first option won't exist any more. By that time hopefully most people switched to electric heating. Then this 1 kWh will save 400 g of CO2 again. Or, even better, switched to heat pumps, then it saves over 1 kg of CO2 emissions.

Yes, by that time also we (again I am talking about the UK) should also have improved insulation which will reduce demand further. Let's assume that we don't achieve this until 2050; is it not wise to investigate the potential of achieving a material reduction in GHG emissions 20 years earlier?

 

[pbuk]

At least here in the USA, many (most?) gas pipes are steel. Using Hydrogen in them brings up the problem of making the steel pipes brittle, leading to fractures... and a pure Hydrogen flame is invisible! (no incandescent Carbon to generate visible light.)

https://scholar.google.com/scholar?...+in+steel&hl=en&as_sdt=0&as_vis=1&oi=scholart

Not saying it can't be done, just that there are a lot 'unmentioned circumstances.'

Cheers,
Tom

This is less of an issue in the UK - we are already replacing much of our infrastructure (particularly the local network within 30 metres of buildings) with MDPE for safety reasons. Invisible flame is not really an issue because:

• this project is looking at a 20% H2 mix
• flames in domestic boilers are hidden
• flame failure devices are mandatory on (new since 2008) gas appliances in the UK - a real pain when trying to cook dinner!

It's probably time for some references:

• The HyDeploy web site with more information about the pilot projects and timeline for this project
• The UK TIMES energy systems model which has been used to model energy supply and demand in the UK, resulting in the target operating model and timeline
• Enforcement Policy for the iron mains risk reduction programme 2013 - 2021

 

[Rive]

...if you could generate that hydrogen using surplus renewable capacity at times of low demand...

Right now (and anywhere in the foreseeable future) it is a 'no'. With the low efficiency of the electricity => hydrogen conversion and the cost (CO2 footprint of building/maintenance/running included) of the relevant machinery this is a losing business for any other time but when seriously negative electricity prices dominating the market.
But by that time most utilities would be long out of the grid anyway.

While it is nice to know that the gas pipes can tolerate 20% hydrogen, this statement right now (and within the next few decades) has very little practical value.

Unless some new technology got developed to radically increase the productivity of hydrogen generation, there are far better solutions to reduce CO2 emission with available cheap electricity.

 

[mfb]

Let's assume that we don't achieve this until 2050; is it not wise to investigate the potential of achieving a material reduction in GHG emissions 20 years earlier?

I don't think anyone argued against research. You asked about wide-scale implementation. And that is not a good idea today. In the very rare cases where renewables cover so much that the energy can't be used at all this might be interesting - but setting up large electrolysis plants for something that happens once or twice per year isn't useful.

 

[Vanadium 50]

Let's redo your calculation: 89% of US commercial and residential emissions are from natural gas. Replacing 20% of this (assuming this can be done without creating additional emissions) could change US domestic emissions by 18%.

Only if commercial/residential were 100% of US emissions. But it's 12%.

surplus renewable capacity at times

I don't think our problem is that we're drowning in "surplus renewable energy at times".

 

[member 656954]

I've seen a few analysis that forecast that the cost of renewable hydrogen (REH2) will be close to, or slightly higher than, natural gas costs. On that basis, without a carbon tax to underpin the economics of change, the wholesale adoption of any hydrogen use case is unlikely.

 

[russ_watters]

I've seen a few analysis that forecast that the cost of renewable hydrogen (REH2) will be close to, or slightly higher than, natural gas costs.

I'd like to see that analysis, because I can't imagine that being true. I'd bet it's an order of magnitude more expensive.

 

[Rive]

I'd bet it's an order of magnitude more expensive.

After following the green business for some time already I've started to ignore entirely every and all analysis based on experimental technology only instead of actual industrial practice.

 

[pbuk]

You asked about wide-scale implementation.

I don't think I have asked anything - perhaps you are confusing me with the OP. This thread does seem to have wandered a little with some confusion over what we are talking about. Perhaps it's time to go back to @tech99's OP, with some editing for clarification:

Can this be a quick solution to reducing domestic CO2 emissions?
Can introduction of 20% H2 into the domestic (i.e. residential) natural gas supply be a quick solution to reducing CO2 emissions from homes in the UK?

It's possible, and because over 80% of homes in the UK use individual gas boilers for heating and hot water the short-term options for reducing domestic emissions are limited. Note however that even if it is feasible (the current HyDeploy trial is a small-scale investigation of this feasibility) there are other factors to be be considered. These include the environmental opportunity cost of the energy used to generate the hydrogen, in other words whether it would be better to use this energy to replace other GHG emissions particularly from fossil fuel fired power stations.

Or is it better to use battery storage and use the electricity?

This is not a short-term option for heating homes in the UK.

What is the best way of using wind and solar for electric cars?

I think this is a topic for a different thread.

Is the domestic heat pump a better long term investment for home heating?

It may well be - but the key words here are 'long term'. Replacing c.20 million gas boilers will take many years and many £ billions, and key decisions including what technolgy and how it will be paid for have not yet been taken in the UK. The Keele trial is looking at a less optimal solution that can be implemented quickly and cheaply while we are working towards the long term solution.

(Minor edits for readability)

 

[member 656954]

I'd like to see that analysis, because I can't imagine that being true. I'd bet it's an order of magnitude more expensive.

Such reports are not too hard to find, @russ_watters, here's one, two, and three (though this last needs your details to get the underlying calcs) as examples of various price curves. Note that I've not seen any forecast that predicts really cheap REH2, hence my carbon tax comment. If it's not cheaper than incumbent natural gas, then without an external driver, change will not happen. Esp. because it's going to cost $T to retool everything for hydrogen.

(I'm also aligned with @Rive's comment about ignoring forecasts for things that are not productionized. Probably REH2 will be cheaper...or more expensive...but don't ask me to be any more accurate than that )

 

[mfb]

I don't think I have asked anything - perhaps you are confusing me with the OP.

Okay, let me be exact: You didn't ask, you made a statement about wide-scale implementation.

...domestic CO2 emissions in the UK could possibly be reduced by up to 20% almost overnight using this solution.

And, as discussed, this isn't true. Wide-scale implementation now would increase CO2 emissions. It can only decrease CO2 emissions if the gas power plants have been replaced largely, at least in frequent times of peak renewable production.

 

[pbuk]

Okay, let me be exact: You didn't ask, you made a statement about wide-scale implementation.And, as discussed, this isn't true. Wide-scale implementation now would increase CO2 emissions. It can only decrease CO2 emissions if the gas power plants have been replaced largely, at least in frequent times of peak renewable production.

We are talking about two different things. I am saying that domestic CO2 emissions in the UK (i.e. emissions from people's homes) could possibly (i.e. making certain assumptions which have to be further developed and trialled) be reduced in the short term (i.e. years rather than decades) by introducing H2 into the natural gas supply.

You are saying that if this were done, the net effect would be to increase CO2 emissions because of the energy used in producing the H2. This may or may not be true, but it has no effect on the validity of my statement because I am talking about only the emissions from people's homes NOT the total emissions based on any assumptions about the energy used for H2 generation.

My final attempt to clarify what I am saying is to express it symbolically:
Let $G_0(UK) = G_0(homes) + G_0(other)$ and $G_1(UK) = G_1(homes) + G_1(H2) + G_1(other)$
My statement: $G_1(homes) < G_0(homes)$ your statement: $G_1(homes) + G_1(H2) > G_0(homes)$
Do you not agree that both these statements can be true?

 

[russ_watters]

Such reports are not too hard to find, @russ_watters

On PF we require people to provide sources for their own claims. Sometimes I'm willing to do others' research for them, but often when the claim seems far off I don't bother.

here's one, two, and three...

The first is behind a paywall and the third is talking about future potential. The second, however, says hydrogen from electrolysis is currently about nine times more expensive than reforming it from natural gas. It would be even worse vs just using the natural gas itself. Oddly, they give the future cost as an exact number, but today's cost as a range.

This really does badly fail the smell test, and it should be pretty obvious from logic or simple cost research.
1. Current energy costs are publicly available, but for people who use natural gas for heating the numbers for gas and electricity are right there on the bill, with only simple conversions of the energy values needed for a good comparison. I've been watching my parents' for comparison to mine since I use propane: electricity is about five times more expensive than natural gas (propane about 3x)...

2. ...And that's before you use the electricity to make hydrogen. Look at the process from start to finish: You have some natural gas. What can you do with it?
a. You can sell it.
b. You can run it through an expensive industrial plant and make electricity (at a loss of efficiency), then sell the electricity. Obviously the electricity has to be much more expensive than the gas was.
c. You can run it through an expensive industrial plant to make electricity, then run the electricity through another expensive industrial plant (at additional lost efficiency) to make hydrogen. Then you can sell the hydrogen in exactly the same way you would have sold the natural gas in the first place.

Obviously it must always be much, much more expensive to make hydrogen from electricity from natural gas and much more expensive to make electricity from natural gas, than just sell the natural gas. Each step in the process makes the resulting energy several times more expensive than what you started with.

Now, I used natural gas here because the comparison is linear and obvious. But what about if we use solar? Well the obviously issue is; how does the cost of solar electricity compare with natural gas fuel? Well, to answer that, let's jump in at step b: is solar electricity a lot cheaper than natural gas electricity? No, it's not -- it's still more expensive. So there's no alleviation of the giant two-step cost escalation by using solar instead of natural gas.

 

[member 656954]

On PF we require people to provide sources for their own claims.

Sorry, wasn't intending to be tricky.

And I mostly agree with your logic, apart from gas generating cheaper electricity than renewables. Lazard's latest LCOE analysis costs utility solar and wind below gas combined cycle and well below gas peakers. It doesn't really change the economics of creating hydrogen, though. It's going to be expensive and to get right back to the OP, unlikely to make a meaningful dent on CO2 emissions.

In the time will take to fund the H2 generation companies, provision and scale the plants, suffer through the bankruptcies cycle as dreamers and fools get swept away, and establish the interconnects, RE electrical generation will have only dropped further in price, storage costs will have dropped, and a carbon price will have kiboshed burning fossil fuels in any event so the painful transition away from gas (or gas+H2) and to electrical everything will have inexorable momentum.

 

[Rive]

Lazard's latest LCOE analysis costs utility solar and wind below gas combined cycle and well below gas peakers.

As being an end-user I'm a bit unhappy with this kind of stuff since it is not cost what's on the bill but some kind of system level price. And the price (increase) generated by different sources feels quite different to the accounted cost.
The 'paradox' is well known and widely debated, but there are just a few study (of acceptable quality) yet so I would rather not link anything at this point.

Obviously it must always be much, much more expensive to make hydrogen from electricity from natural gas and much more expensive to make electricity from natural gas, than just sell the natural gas. Each step in the process makes the resulting energy several times more expensive than what you started with.

The proposed Hydrogen generation is actually based on double utilization: one is about to use it for load side balancing of the grid, the second is to save the curtailed part of wind/solar generation. So it would not be that bad - still, the price remains terrible.

Also, I have some doubts about the load side balancing part. It is expected to save some natural gas, but on the other hand it is making ways for chap coal to keep positions => sure it san save cost, but will it actually save CO2 emission?

 

[russ_watters]

And I mostly agree with your logic, apart from gas generating cheaper electricity than renewables. Lazard's latest LCOE analysis costs utility solar and wind below gas combined cycle and well below gas peakers. It doesn't really change the economics of creating hydrogen, though. It's going to be expensive and to get right back to the OP, unlikely to make a meaningful dent on CO2 emissions.

As being an end-user I'm a bit unhappy with this kind of stuff since it is not cost what's on the bill but some kind of system level price. And the price (increase) generated by different sources feels quite different to the accounted cost.
The 'paradox' is well known and widely debated, but there are just a few study (of acceptable quality) yet so I would rather not link anything at this point.

Let me expand on that issue a bit(I haven't read the sources yet). Right now, solar (and wind, but we are mostly discussing solar) is treated as stand-alone when its energy costs are analyzed. That's unfair to other sources because solar adversely affects their pricing and production. Essentially, it is a hidden subsidy provided to solar, from (mostly) natural gas.

Let me put it another way: Say you shut down a 100 MW coal plant and replace it with a 100 MW solar plant. Groovy, right? Wrong: since solar often produces nothing, you also need to build 100 MW natural gas plant to provide up to 80% of the annual energy (if it was a baseload coal plant). But in the typical analysis the two projects are treated as if they were separate, even though the electricity is much more expensive than if you had just built the natural gas plant. The natural gas plant has the same capital cost, but it sells 20% less energy in this scheme, and at lower rates. So a lot of the economic downside of the solar plant is paid for by the gas plant.

This a lot of the reason why Germany and California have such expensive electricity.

 

[member 656954]

As being an end-user I'm a bit unhappy with this kind of stuff since it is not cost what's on the bill but some kind of system level price.

Yep, retail price transparency is an issue, compounded by the variance in global retail prices and the diverse electrical supply chain - entirely State owned, privatized but price capped, private but regulated, entirely deregulated - making any analysis of that kind very difficult. Also, while retailers typically publish standard tariffs, customers can be on special deals / hardship deals / time of day deals / etc. and retailers cite commercial in confidence requirements to keep what's actually paid by the customer opaque.

But that does not detract from the system cost comparisons, as those are the ones regulators and investors use to decide the merit of generation projects, and empirical methods can be applied to establish consumer cost ranges from the system level price. Because domestic energy cost increases have been highly politicized in Australia, their consumer commission did an analysis in 2018 that provides an example of such supply chain cost split.

Wrong: since solar often produces nothing, you also need to build 100 MW natural gas plant

Yes that's the typical gas peaker plant, but we are seeing instances of them being replaced with PV+storage and some States (e.g., Arizona, California, Colorado, Indiana, Nevada, Virginia) are legislatively favoring RE as the cost of PV / wind / storage cost curve is making fossil fuel plants - even gas - uneconomic.

That's why I think the 'electrify everything' trend is a better investment than gas+hydrogen, because the moment we have a price on carbon is the moment the exodus from gas for domestic use starts in earnest. Most retail customers are already baying at the cost of energy and adding a "gas tax" will drive prices up, not down.

 

[anorlunda]

That's why I think the 'electrify everything' trend is a better investment

What makes you think that your opinion matters, or opinions of others like you? Investors have their own opinions, and they hire their own consultants, and that is what counts.

 

[mfb]

Investors have their own opinions, and they hire their own consultants, and that is what counts.

Then we should give these investors incentives to consider the environment in their decisions. Read: A carbon tax. But I don't want to get political.

 

[anorlunda]

Then we should give these investors incentives to consider the environment in their decisions. Read: A carbon tax. But I don't want to get political.

Investors don't need to get political at all. They are free to invest their money in Apple, or entertainment, or health care, or real estate, or art.

I'm sure you have some savings. Can the government tell you where to invest it?

Utilities are bound to the energy sector, but private investors are not. Even public utilities need to sell bonds to private investors.

 

[member 656954]

others like you

Waaa? You mean someone who does strategy work with energy regulators and assesses investment targets for private equity firms for a living? Then sure, others like me

 

[anorlunda]

Waaa? You mean someone who does strategy work with energy regulators and assesses investment targets for private equity firms for a living? Then sure, others like me

Apologies. I should not have implied more than was warranted. Are you saying that is your active profession?

The point that I meant to make is that public opinion, and the popularity of different energy schemes don't matter much to private investors. Regulators can make tough regulations, but the result may just be to scare private investors away from the energy sector.

 

[chemisttree]

Does 20% hydrogen cause only 20% of the hydrogen embrittlement in those cast iron distribution lines? Wouldn’t this idea only hasten end of life for susceptible metal components throughout the distribution network?

 

[mfb]

which is around 7 per cent of the annual CO2 tonnage churned out by the burning of fossil fuel around the world.

These 7% are offset by our food production which binds as much CO2 as we exhale again. The burning of fossil fuels is not balanced.

 

[member 656954]

Apologies. I should not have implied more than was warranted. Are you saying that is your active profession?

LOL, your comment did seem a little direct, @anorlunda, but I take your point regards opinion. And yes, this is my active profession.

 

[member 656954]

Does 20% hydrogen cause only 20% of the hydrogen embrittlement in those cast iron distribution lines? Wouldn’t this idea only hasten end of life for susceptible metal components throughout the distribution network?

The embrittlement is not as linear as that, as it depends on pressure and structural irregularities, but hydrogen will increase the failure rate over non-hydrogen in operation. NREL released this excellent summary of hydrogen in gas pipeline distribution studies, including a conclusion that hydrogen concentrations up to 28% may safely be used with properly serviced existing domestic appliances.

 

[tech99]

Can I thank everyone for the replies and discussion on Hydrogen Injection which has turned out to be a complex issue. I was hoping it would avoid building new electricity stations to supply electric cars, because there are issues about the technology and also the effect on habitats.

 

[Genava]

These 7% are offset by our food production which binds as much CO2 as we exhale again. The burning of fossil fuels is not balanced.

Thank you. That's the difference between someone understanding the basics about the carbon cycle and someone who doesn't.

 

[bigfooted]

The embrittlement is not as linear as that, as it depends on pressure and structural irregularities, but hydrogen will increase the failure rate over non-hydrogen in operation. NREL released this excellent summary of hydrogen in gas pipeline distribution studies, including a conclusion that hydrogen concentrations up to 28% may safely be used with properly serviced existing domestic appliances.

Domestic boilers have to be tested under extreme conditions (well, more extreme than what they would encounter in their lifetime) before they are released on the market. One of the tests is a light-back safety test where a mixture of 23% H2 +77% CH4 (mole-fraction) is used. So all domestic boilers on the European market passed this test. Very old or very different appliances (certain gas turbines) are the limiting factor for widening the fuel flexibility of the gas network, and they may need to be banned when changing the gas composition on the network.

That's why I think the 'electrify everything' trend is a better investment than gas+hydrogen, because the moment we have a price on carbon is the moment the exodus from gas for domestic use starts in earnest.

Well, a lot of electricity comes from gas or coal power plants, so unless you exempt power plants from carbon tax, the electricity price will also go up. Also, a complete switch from gas to electric is not possible without upgrading the entire network up to the fuse box and this will certainly have an impact on the electricity price.
Anyway, if we want to decarbonize, we need to get rid of natural gas completely and adding hydrogen to the gas network is a nice intermediate solution: the gas lines do not need to be replaced (at least not in the UK and in the Netherlands, don't have information about other countries) and many appliances can handle the larger hydrogen concentrations. With this experience, the next step will be to switch to 100% hydrogen on the gas lines, as proposed in e.g. the H21 Leeds city gate project as well as the Hy4Heat program in the UK. Hydrogen production technologies will be more mature and hydrogen prices will drop when more hydrogen will be available.
All in all I think the 'electrify everything' trend might not be a better investment than a combined electric + hydrogen network.

 

[member 656954]

hydrogen prices will drop when more hydrogen will be available

Do you happen to have any articles or studies that predict this, @bigfooted? I'm struggling to find any that don't cost out to be at least the gas price...or more.

 

[gmax137]

With this experience, the next step will be to switch to 100% hydrogen on the gas lines, as proposed in e.g. the H21 Leeds city gate project as well as the Hy4Heat program in the UK. Hydrogen production technologies will be more mature and hydrogen prices will drop when more hydrogen will be available.

Where is this hydrogen coming from? How much are we talking about?

Please Check my arithmetic:

google says UK natural gas consumption is about 7.6 billion ft3 per day
at 1000 Btu/ft3
and 3413000 Btu/MW-hr
I get
93,000 MW
That's a lot of windmills.

 

[member 656954]

Where is this hydrogen coming from? How much are we talking about?

That is the big question, @gmax137. With efficiency losses, creating hydrogen from renewable sources is more than "a lot of windmills".

The UK generated 75.2 TWh of electricity from gas in Q1 2019, while renewable electricity (RE) generation was 31.1 TWh in the same period, but solar and wind was only 23.6% of that. Gas accounted for 41.5% of total generation in the period (coal was only 3.5%, a record low), which shows how large the generation gap is, and that does not account for the efficiency loss creating the hydrogen. It is also not all energy used in the UK - just electricity!

Still RE is increasing, year-on-year, and was up 9.2% on the same period in 2018, but we clearly have a long way to go.

 

[Rive]

...we clearly have a long way to go.

Not really. Not clearly, at least. The whole Hydrogen generation came from the idea of taking the surplus RE as 'free'. Just this 'free' alone is a serious misconception, but it gets even worse when it is paired with the 'long way to go'.
It is a known problem that with the improving penetration of intermittent RE the grid is more and more strained, and system operators are more and more frequently forced to reject taking in more wind, even if it costs them money (look up 'curtailment'). This also means that above a point the new wind capacity is actually reducing the capacity factor of the whole installed capacity, messing up any investment/return calculations.
Hard to say where is actually the point when new capacity is no longer advantageous anymore, but California and Germany already clearly closing to that point.

 

[member 656954]

Not really. Not clearly, at least.

Not sure you're saying what I think you are saying, @Rive. RE provided about 11.0% of total UK energy consumption in 2018, and for me, at least, 89% is a long way to go

I understand the rest of your post (including curtailment), and agree with it. The hydrogen economy concept makes no sense to me.

 

[Nik_2213]

I'm old enough to remember 'Town Gas', which was a very nasty CO + H2 mix. IIRC, there was an art to crafting joints and connections that so-slippery H2 would not get through in quantity. Then I used H2 for GC instruments, again met that so-slippery molecule. Ninja-fu Helium was worse for containment, but essentially harmless...

As a ~20% blend, H2 may be some-what more dangerous than pure methane. The 'Flash-over' danger will be less than that infamous ~50% Town Gas mix, but explosion shock fronts would be faster than pure methane. Will ~20% allow catalytic ignition ? I missed being able to wave a 'Cerium' ceramic-coated wand over burner to light it...

 

[reiver]

I work in renewable energy for a company that is testing this approach - issues such as grid connections for offshore wind farms are part of the reason for interest - it is one of the trickiest elements to ensure that there is a grid connection available with the capacity that you need and that you have permisison to connect to it.

Another reason for interest is ctually exploring the concept using in-house utilities knowledge of cost bases and network infrastructure - in Europe, many of the transmission networks are owned by companies also involved in generation). The view is largely of what utilities can do to avoid curtailment.

The 20% H2 value is largely predicated on the modern domestic boilers needing no change to be able to burn this fuel, so adding the 20% H2 would not require any significant infrastructural changes (and these would incur significant costs).

RE would always focus on electricity generation and the way that RE is going, merchant price is becoming the mechanism i.e. if there is low demand for electricity, it can't be sold and you don't get paid for curtailment for power that hasn't been sold already (curtailment tends to be agreeing to come off grid having contractually promised/agreed to provide power - CCGTs (gas plants) get paid for curtailment in the same manner). But if the wind is blowing anyway, is there a way to sell the excess potential electricity? This electricity has low marginal cost so is the "free" electricity that everyone is talking about. So these H2 trials are more to see that it can be done and if there are any unexpected problems and to do so at very low cost.

[Moderator: paragraph breaks added for readability.]

 

[Christopher L]

At least here in the USA, many (most?) gas pipes are steel. Using Hydrogen in them brings up the problem of making the steel pipes brittle, leading to fractures... and a pure Hydrogen flame is invisible! (no incandescent Carbon to generate visible light.)

https://scholar.google.com/scholar?...+in+steel&hl=en&as_sdt=0&as_vis=1&oi=scholart

Not saying it can't be done, just that there are a lot 'unmentioned circumstances.'

Cheers,
Tom

"H2S plays a multiple role in increasing hydrogen permeation of passivated steel in slightly acidic environments. It increases the rates of iron corrosion and proton discharge and poisons the hydrogen evolution reaction on the depassivated surface, thereby permitting a large fraction of hydrogen atoms to enter the metal."

The Role of  H 2 S  in the Corrosion and Hydrogen Embrittlement of Steel
B. J. Berkowitz and H. H. Horowitz

© 1982 ECS - The Electrochemical Society
Journal of The Electrochemical Society, Volume 129, Number 3

https://iopscience.iop.org/article/10.1149/1.2123882/meta