Image by Anne Lund from Wikipedia reproduced and modified under GNU 1.2 |
Don't get me wrong, hydrogen is a wonderful element - literally the number one. There is a specific irony in my use of that image because, of course, hydrogen is the fuel of that vast nuclear reactor that keeps us alive - and, for that matter, it's one of the two component elements of the water that is essential for life.
I am also not denying that hydrogen has a useful role in the future green economy. It's often mis-described as an energy source. It's actually an energy store, and as such could be useful as a way of storing away renewable energy. For example, solar energy can be used when the Sun is not shining by producing hydrogen at power stations that is later cleanly burned. It is also a potential fuel for large, specialist vehicles if batteries are not a sensible option, such as long range buses, lorries and possibly aircraft.
However, there are two 'green energy' applications of hydrogen that are still mentioned but that have serious problems.
One is in cars. The Grand Tour presenters (formerly of Top Gear) have frequently praised hydrogen as a petrol replacement, in opposition to electric cars. But for me it has three issues. One is it's even less safe to handle and live with than petrol. A second that it has lower energy density than petrol, so you get less range for the same tank size. But the biggest one is that hydrogen ties us to fuel stations. We already have a much bigger distribution network for electricity. When, many years ago, I had a Mondex card, the original experimental cashless card, its biggest plus was I could top it up at home - I didn't have to go somewhere to get cash. The same applies to electric cars. Of course they need to be cheaper and with better range, but that will come. But who would want to keep filling stations if we could get away from them?
The other problematic application is using hydrogen as a replacement for gas heating in homes. The idea is that you put hydrogen down the same pipes we currently put natural gas down - so, like electricity, the distribution network is already there to the point of use. Sounds great. But I was always worried that hydrogen, which is better at leaking than natural gas would find far too many ways of escaping... and I'd rather get away from pumping highly flammable substances into the home.
Now, though, there's a second and even more convincing reason - it's not a cheap solution, nor is it even particularly green. This isn't a comment from an alarmist source, it's the outcome of a review of 32 independent studies, reported in Chemistry World. As the original study notes 'it takes about five times more electricity to heat a home with hydrogen than it takes to heat the same home with an efficient heat pump, either individually or as part of a district heating network.' This is not the green future.
This has been a Green Heretic production.
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