From Charles Purkess, ITM Power
It is unfortunate that David Strahan concluded his article on hydrogen as a fuel by returning to the arguments of the 20th century, focusing on comparing the efficiency of batteries with hydrogen. He completely overlooked the stark reality of the 21st-century global climate challenge and economics, not to mention the acute energy and fuel-supply issues for the UK (29 November 2008, p 40).
Matching energy generation to demand is difficult for many of the renewable energy resources now being installed. The key to effective and economic utilisation of the output from such renewable resources has to be through energy storage.
Much of our present use of hydrocarbons is directed to transport applications, and if the stored energy could be provided in the form of an environmentally neutral chemical fuel suitable for reuse in the existing transport sector it would be of great national importance. The best available answer is hydrogen.
From R. Gammon, Bryte Energy
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As the world moves towards low-carbon energy systems, an increasing proportion of primary energy will need to be generated from highly variable wind, solar and other renewable sources, as well as relatively inflexible generators like nuclear and “clean coal” plants.
To provide a buffer during excess electricity production, the electrolysis of water to produce hydrogen will play an important role. It’s a process that generates a fuel as a by-product of grid balancing, rather than presenting an added burden to the energy system.
However, the low “round-trip efficiency” of converting electricity to hydrogen and back again means it is not the preferred option for the storage of grid electricity, which might be better achieved with flow cells such as the vanadium battery (11 October 2008, p 30). Hydrogen’s main role in a low-carbon energy system is in the transfer of energy from the power generation to the transport sector.
Loughborough, Leicestershire, UK
Wendens Ambo, Essex, UK
