Hydrogen

I was interested to read this morning that our government is proposing to spend £500m on using hydrogen as a fuel. 

I don't know over what period this sum is to be spent or what proportion of this sum is new money - that is to say money diverted from some other project to this one - although with announcements of this sort one usually finds on inspection that around the half the headline sum - in this case £500m - was already being spent, was already committed anyway. The wonders of self-promotion.

The good thing about hydrogen as a fuel is that when you burn it you get just heat and water. No greenhouse gases.

The bad thing about hydrogen is that it is not just lying around, under the ground or anywhere else. But it can be extracted from natural gas and from other hydrocarbons, be they of geological or biological origin. This all sounds rather expensive and inefficient - and leaves you with carbon dioxide which needs to somehow be captured and stored. However, hydrogen can also be extracted from water if you fire enough energy at the water - something that a giant solar mirror might manage. Or more conventionally with electrolysis, but using electricity generated by solar panels or windmills, rather than by burning charcoal, natural gas, coal or oil. Which all sounds just perfect. Your solar power station produces clean hydrogen from water. You bottle the stuff up to fuel motor cars and domestic boilers. Maybe much better than the alternative of pumping the electricity into large batteries. The cars and the boilers then turn the hydrogen back into energy and water - and do their business. Not a greenhouse gas to be seen anywhere.

So maybe there is something in it, accessibly introduced at reference 1. But I am glad it is not me that has to decide how much it is worth betting on this one as part of our effort to save the planet from the effects of burning too much carbon.

PS: along the way I learn that if you mix very hot steam with carbon monoxide, you cook up a mixture of hydrogen and carbon dioxide. The former being useful and the latter being a lot less toxic than its precursor, carbon monoxide.

Reference 1: https://www.energy.gov/eere/fuelcells/hydrogen-production-processes.

Reference 2: https://psmv4.blogspot.com/2020/07/a-black-error.html. A previous outing for charcoal.