Sunday 23 August 2020

Green hydrogen - seems completely pointless.

From Forbes:

In the long-term, 'blue' hydrogen is seen as an intermediate step towards the cleanest form of H2, 'green' hydrogen — so called because its production emits little or even zero carbon.

'Green' hydrogen can be produced by separating hydrogen from water via electrolysis, though other technologies are emerging. When the electricity used to perform the process comes from renewable sources, green hydrogen becomes truly zero carbon.


It will surely be far more efficient to use the electricity (whether from renewables or not) to power things directly than to use the electricity to split water into hydrogen and oxygen first and then power things by burning hydrogen again. And a lot less dangerous.

And there are plenty of other ways of storing electricity (particularly important if you intend to rely on 'renewables') which are a lot cheaper and safer. Like pumping water uphill or pressurising air.

So who is behind this nonsense?

Last month, the EU set out a renewable hydrogen strategy, sketching a roadmap for how the world’s largest trading bloc intends to develop hydrogen production and usage through 2050. Also last month, the German government announced it would invest €9 billion ($10.7 billion) in its own national hydrogen strategy.

Now, the U.K.’s Hydrogen Taskforce, a coalition of companies and industry bodies, has called on the government to recognize hydrogen as a key component for a “green recovery” from Britain’s historic recession.


The usual corporatists, in other words.

17 comments:

Piotr Wasik said...

This guy (Robert Zubrin, a Mars fanatic) also writes https://www.thenewatlantis.com/publications/the-hydrogen-hoax that it leaks through all gaskets therefore cars would pose an explosion risk in any garage, and it brittles and weakens metal in pipes and containers, and it costs a lot of energy to compress it (but then why not recover the energy from compressed hydrogen before it is burned). He sounds knowledgeable, but energy and material engineering is not my field.

Mark Wadsworth said...

PW, thanks, that's an excellent article which explains it all properly.

Bayard said...

So, "green hydrogen", like so many other green things, is just a new and efficient way of transferring public money into private pockets.

Derek said...

Rentiers like the "hydrogen economy" because it relies on centralised production and distribution of fuel. The production is said to be too difficult (or perhaps dangerous, or amybe expensive) for the general public to do it themselves. Which gives the rentiers a nice little monopoly, similar to the current "hydrocarbon economy" with plenty of opportunity to extract rent.

Of course they are much less happy with the alternative "rooftop solar electric vehicle" economy which decentralises energy production and takes away their ability to charge rent for energy. So they are pushing governments to go down the hydrogen route, in order to maintain their current "rent extraction" model.

In my opinion.

Lola said...

There is a project to make 'green' petrol. F1 are behind it.
I think the idea is to use off peak electricity or wind power, or something.

Mark Wadsworth said...

B, yes.

D, good points.

L, that's different, F1 is just doing stuff for the sake of doing it, they aren't asking the government to give them control over energy supplies. Plus I'd be happy putting their petrol in my cars, I'd be a bit nervous about filing it hydrogen.

benj said...

@MW

1 Hydrogen isn't as dangerous as you might think.
2 There aren't enough places for pumped hydro in the UK to flatten out the differences in demand and supply for renewables.
3 The efficiency of electrolysis and pumped hydro are about the same.
4 The costs of EV's(including subsidies) and ICE are about the same in the UK. If direct air capture/seawater capture technologies can be scaled up, combined with H2, a 70p per litre synfuel has been projected. Seeing as that's CO2 neutral, no fuel duties.
5 30 million EV are going to need charging. Off street, on street, public chargers etc. Who knows what the cost of this will be, except its going to be massive. We've already infrastructure for liquid fuels, whether that's synfuels, or compressed H2 for fuel cells.

Mark Wadsworth said...

B,

1. Hmm.

2. You can do pumped water, compressed air, lifting weights. The latter two can be done anywhere on fairly small scales.

3. Maybe.

4. The actual cost of ICE is hugely lower than EV. It is the fuel duties which levels this. Tax-free petrol actually only costs about 40p/litre.

Fuel duties have the huge benefit of being rent-for-road space and simpler to administer than road pricing (they come to much the same thing). EVs use just as much road space as proper cars.

5. That is surmountable. A new EV car costs (say) £30,000, an EV charging point costs (maybe) £1,000.

I did the numbers, we'd have to increase generating capacity by a third or a half to produce enough electricity for everybody to drive EV (and charge them overnight). That's the sticking point. And for it to make any sense, the electricity would have to be from renewables.

George Carty said...

If you're going to use rooftop solar panels to charge electric cars, wouldn't they need to be on the roofs of workplaces rather than homes, because that is where the cars would be parked during most daylight hours?

Mark Wadsworth said...

GC, first calculate the area of panels needed to charge one car...

Mark Wadsworth said...

GC, thankfully, somebody has calculated this. It is a lot of panels.

George Carty said...

I was making the point in response to Derek.

Mark, I get the idea that you're an EV-sceptic, given that you said "EVs use just as much road space as proper cars": am I right, and if so what is your rationale?

Still think EVs are a much better idea than hydrogen cars though: the problem with hydrogen isn't just safety: there's also the fact that hydrogen's minuscule molecules make it extremely difficult to make leak-proof pipework. Plus while hydrogen has excellent energy per unit mass (which makes it good for space rockets) it has terrible energy per unit volume.

I'm guessing F1 invested in "green petrol" largely as a way to get the environmentalists off their backs. It wasn't too difficult given that F1's fuel consumption is tiny compared to that consumed by people driving to and from work (or at least it was before Covid-19 got most of us working from home...)

Mark Wadsworth said...

GC, aha, it was a good point anyway. If your job is in a single storey warehouse, there might actually be enough roof space for everybody to charge their cars. But not a viable option for most people.

I'm not "EV sceptic". I don't like them, but each to his own. Forget about this whole "MMGW" nonsense for now. What is good about fuel duty is that it is like road pricing, at a minimum of intrusion and admin hassle. Road use is something worth taxing, however the vehicle is powered. (Fuel duties have loads of positives, and I say that as somebody with three cars).

As to safety, Benj reckons hydrogen is not that dangerous. It sounds crazy to me.

Bayard said...

Mark, there's lots to like about electric vehicles, the performance for starters - full torque from standstill.

"GC, thankfully, somebody has calculated this. It is a lot of panels."

Those figures are for the US, where they drive a lot more than we do in the UK. They also assume that the car is used to drive to work, which is usually not the case in cities, where most people live. It also assumes that you have grid-connected panels, which, now that the feed-in tariffs have gone, will also be increasingly not the case.


Derek said...

I was just pointing out why rentiers might prefer solar-generated methanol or hydrogen to electricity. Sure, there are other issues with solar panels but that's for another day.

Mark Wadsworth said...

B, read the linked article. It is based on US drivers doing 14,000 miles a year, which is more than the average UK driver, but in the same ball park.

As to "full torque from standstill", I am not a speed freak. The accelerating is part of the fun, so I have ten seconds of fun doing 0-to-60 and the EV driver only has two seconds of fun.

D, solar panels are great in the right context.

Physiocrat said...

There is a mad scheme for hydrogen powered trains. Overall thermal efficiency is about the same as a steam locomotive burning light oil, which cost about one-third and can haul any old carriages which happen to be lying around.