Recent press coverage of BP’s partnership with Aberdeen, where BP will become the planning and technical adviser on the “net zero vision” for Aberdeen 2045, together with the AREG chairwomen’s EV article on ‘A hydrogen future on the horizon’, raised concerns in my mind relating to over-selling hydrogen.
Aberdeen’s commitment to a net zero future is to to be applauded but I’m of the opinion that the hydrogen push has to be questioned on technical and economic grounds.
Much is made of the city’s hydrogen bus initiative. The low carbon alternative to the hydrogen bus would be the battery bus. The hydrogen bus fleet in Aberdeen uses electrolysers to generate hydrogen. Electrolysis combined with a hydrogen fuel cell is, give or take, half as power efficient as a battery, so hydrogen will cost twice as much for each km travelled. Furthermore, the electrolysis facility will require a wind farm double the size of that required by a battery. Not true say the hydrogen proponents; a battery bus will be heavier because of range limitations. Range requires a heavier battery reducing the operational efficiency of the battery bus. That is true but why do you need a long range for an urban bus? Inner city Aberdeen bus routes are less than 20 – 30 km and depot charging facilities could be supported by supplementary charging at the start and end points of the city routes. An urban bus does not require a high range battery. Furthermore, battery power densities are continually improving which only reinforces the case for me that battery buses will inevitably be the better cost option for the Aberdeen commuter. Coventry recently came to that conclusion and has ordered a fleet of double decker battery buses.
Aberdeen also seems set to trial the use of hydrogen for domestic heating. Using hydrogen for domestic heating is very inefficient compared to heating households using heat pumps. A domestic heat pump will use on average 3 -4 times less energy than hydrogen. On that basis hydrogen for heating does not stack up. Again not true say the hydrogen proponents; hydrogen can be readily deployed cost effectively through the existing gas distribution system. When the energy production (four times larger for hydrogen than heat pumps), electrolyser or reformer with CCS, hydrogen compression, treatment, storage, distribution and boiler conversion costs are combined, I fail to see how hydrogen for domestic heating can have a life cycle cost better than a heat pump.
The UK needs low carbon hydrogen for its use a chemical precursor for production of fertilisers and other very useful chemicals. That is where our low carbon hydrogen focus should be.
I’ll leave safety issues for another time.
Finally, a recent technical paper in the reputable journal Environmental Innovation and Societal Transitions has scientifically demonstrated that there is an anti-electrification pro hydrogen bias. The paper – Heating in Great Britain: An incumbent discourse coalition resists an electrifying future – concluded ‘Incumbents are over-selling ‘green-gas’ to policy makers in order to protect their interests and detract from the importance and value of electrification.’
AREG please take note.
Tom Baxter is visiting professor of chemical engineering at Strathclyde University and a retired technical director at Genesis Oil and Gas Consultants
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