Green Hydrogen - Hydrogen – A Green Future is not Blue

 The Hydrogen Case

 

Confusingly for a colourless gas, the convention is to use colours for hydrogen produced by different processes. Firstly, as mentioned, the existing grey hydrogen. Secondly, we have blue hydrogen, which would also be produced from natural gas, but with theoretically limited emissions as production would be combined with the much hyped technology of carbon capture and storage (CCS). Finally: green hydrogen, which is produced from the electrolysis of water using renewable electricity such that the net carbon emission is definitely close to zero.

So why are we not immediately switching from fossil fuels to blue or green hydrogen? This is because using hydrogen as an energy source also has numerous disadvantages. First of all, for applications like mobility and heating, the required changes to the existing infrastructure will take a long time, cost a lot of money, and it’s not clear to investors how big the actual market will be. Secondly, applications of hydrogen tend to have quite low efficiency compared to competing technologies; the many energy conversions required along the hydrogen supply chain make for rather low overall system efficiency. For example, hydrogen boilers for residential heating and hydrogen fuel cell cars are considerably less energy efficient than their electricity based competitors such as heat pumps and electric vehicles.

Both these disadvantages are compounded when looking at blue hydrogen because CCS is still largely technically unproven and definitely an expensive proposition. Huge CCS capacity would be required for a wide implementation of blue hydrogen and that simply does not exist (and it is hard to see how it can). Ultimately, the blue hydrogen case seems circular and self-defeating; using natural gas to produce hydrogen, which in turn is replacing fossil fuels like natural gas - and at a higher cost. We thus do not believe in the blue hydrogen case. That said, there is a big lobbying effort by some industries, most notably the oil and gas giants, to push blue hydrogen as a way to enable a smooth transition to green hydrogen in the longer term. To us this sounds a bit like vowing to only drink beer at the weekends before you give up alcohol for good.