Large scale hydrogen manufacture is being considered using renewable energy. H21 project. The hydrogen gas will replace methane in the national gas network, just as methane replaced town gas during the 60s and 70s.

So every household will need its burners adjusted for a different fuel - again. I remember it well.

If hydrogen fuel cells were the answer, then that's the way the industry would be going. Instead it's mostly going towards battery electric. Heavy battery packs don't seem prevent electric cars being more energy efficient than petrol or diesel ones. Plus electric cars have regenerative braking, which compensates for any weight penalty. And in a well thought-out design, an electric car has a lot more free space withing the shape, as with Tesla cars - although some other electric cars appear have as much gubbins under the bonnet as a petrol or diesel one!

Edited by Sofa Spud on 09/06/2020 at 17:35

......surplus electricity from wind turbines and solar panels (they should be on every big warehouse in the country) to make hydrogen.

What would you use the hydrogen for?

Cars, e.g.Hyundai Nexo.

Grid scale battery storage is what we need.

Hydrogen would be more compact and convenient - and far less polluting than batteries. No need for all those expensive materials obtained at great cost from abroad to make them, no need for expensive recycling when they wear out and no need to carry a heavy power-sapping battery underneath the car.

Instead you need an industrial quality tank and pipeline in thh car to withstand the pressures. And catalysts to oxidise it in a fuel cell. (VERY expensive materials)

And if stored as a liquid, your tank will naturally empty itself through evaporation over 2-3 days...

And if stored as a gas, a much smaller range...

I agree regenerative braking is a big plus for EVs, but I would contend that hydrogen refuelling is a lot safer than any old - or young - Tom Dick or Harriet grabbing a hose and squirting almost explosive fluid into a large can via an unsealed connection.

I don't understand why, instead of paying millions to renewable energy producers to stop their windmills, we are not using surplus electricity from wind turbines and solar panels (they should be on every big warehouse in the country) to make hydrogen.

What would you use the hydrogen for?

Grid scale battery storage is what we need.

One of the gas companies over here (West Australia) is experimenting with using solar electricity to produce hydrogen and are then injecting it into their gas mains. It seems to be safe enough - I haven't heard of anyone's house blowing up. Whether it is cost effective is yet to be seen.

When we changed over from town gas which contained hydrogen, carbon monoxide and small amounts of methane, to natural gas from the North Sea, which is almost all methane, every domestic cooker, boiler and gas fire had to be converted with different burners: hydrogen flame fronts move much faster than methane, so large percentages of hydrogen could cause problems in appliances designed for natural gas.

I don't understand why, instead of paying millions to renewable energy producers to stop their windmills, we are not using surplus electricity from wind turbines and solar panels (they should be on every big warehouse in the country) to make hydrogen.

What would you use the hydrogen for?

Grid scale battery storage is what we need.

One of the gas companies over here (West Australia) is experimenting with using solar electricity to produce hydrogen and are then injecting it into their gas mains. It seems to be safe enough - I haven't heard of anyone's house blowing up. Whether it is cost effective is yet to be seen.

As it's a trial, I doubt if it's currently of the scale that would be possibly unsafe, given I would suspect a LOT of (expensive) safety precautions have been taken.

Besides, Australia is mostly open space - imagine putting yet more gas lines (and ones that are much more dangerous than natural gas) under the UK's already congested land.

But again, it's the sheer amount of water and electrivity needed to produce it that is staggering - we already have too much fields of PV and landscapes despoiled with wind turbines (pitcuresque windmills they ain't), especially when (as I said earlier) such areas should be either farmed or left for their natural beauty.

PV panels of roofs are fine, but obviously cannot be used to generate much hydrogen onb most as they are too small, and they need to use sea water, not (already scarce) fresh water, meaning that only coastal of increadibly wet areas could have production plants.

Producing hydrogen from water requires massive amounts of electricity. But very little water - 11% by weight is hydrogen, the rest oxygen.

To produce 1kg of hydrogen (which has approx 33KWh of energy) uses approx 42KWh of electricity. So producing hydrogen is approx 75% efficient. This excludes compression, transport and losses in storage.

A fuel cell is approx 50% efficient. This is better than an ICE at around 30%, but much worse than an electric motor which is over 90% efficient in converting stored power into motion.

In summary - taking electricity and converting it to hydrogen to use in a fuel cell to make more electricity wastes over 60% of the electrical energy. The definition of insanity???

Thanks for that link, John - amazingly informative (and entertainingly delivered) for this non-scientist! Notably, it addresses Terry W's arguments on efficiency in a well-balanced and pragmatic way, I thought.