David Cebon, professor of mechanical engineering at Cambridge University.There has been a lot of talk about hydrogen in the past year or two. Advocates for a ‘hydrogen economy’ make claims about how ‘green hydrogen’ (made by electrolysing pure water with renewable electricity) will power future energy systems. The idea is that green hydrogen will be generated at times of day when renewable electricity is cheap (ie when supply is high and demand is low). The hydrogen gas will be stored in underground salt caverns until needed and then either converted back into electricity and injected into the electricity grid or piped around the country to heat buildings and fuel lorries. Over the past year I have researched and written technical blogs on these subjects: on powering lorries, heating buildings and electricity storage, and one bringing together the arguments. Here are my main conclusions: Energy conversion processes required by the green hydrogen economy (electrolysis, compression, storage and fuel cells) are very inefficient: wasting energy as low grade heat. A huge amount of new renewable electricity capacity would be needed to compensate for the wasted energy. The proposed green hydrogen economy is unlikely to be realisable in the UK because of sheer amount of renewable electricity required, the low Technology Readiness Level (TRL) of large scale electrolysis and the undeveloped technology for storing hydrogen in salt caverns. An ‘electron economy’ has a significantly higher likelihood of success, in a much shorter timeframe. For heavy goods vehicles, direct electrification, via batteries and ‘electric roads’, are options with a higher TRL, lower energy consumption, lower carbon emissions and lower costs than hydrogen-powered fuel cell vehicles. Heat pumps are a much better option for heating buildings than hydrogen boilers. Heat pumps are readily available now and have much lower energy consumption, carbon emissions and fuel costs. For electricity storage, green hydrogen is unlikely to be competitive with more efficient alternatives such as cryogenic (liquid air) storage and compressed air storage. Both offer almost equivalent storage capabilities at much lower ‘levelised cost of storage’, and higher TRL. Shifting the energy for lorries and heating buildings to blue hydrogen would result in the UK importing and burning an additional 260 TWh of natural gas per year. This would increase natural gas imports by 50 per cent and increase overall gas consumption by nearly 30 per cent. It would be detrimental to the country’s balance of trade and energy security. The push for hydrogen is likely to delay the international decarbonisation project and undermine efforts to keep the global average temperature less than 1.5 oC or even 2.0 oC above pre-industrial levels.
Green Alliance Blog 11th Feb 2021 read more »
The UK’s first show-homes with heating appliances fuelled entirely by hydrogen are set to open in Gateshead in the spring, in a bid to demonstrate the role hydrogen could play in decarbonising household heating, the Department of Business, Energy and Industrial Strategy (BEIS) announced today. The two semi-detached homes in Low Thornley, which are set to open to the public in April 2021, will use 100 per cent hydrogen for domestic heating and cooking, featuring a range of zero carbon hydrogen appliances including boilers, hobs, cookers, and fires, according to BEIS. Members of the public as well as local school, college, and university students will be able to visit the homes and compare the low carbon appliances to those in their own households, it said. The project, which is being funded through a £250,000 grant from the government’s Hy4Heat innovation programme, as well as £250,000 funding each from gas firms Northern Gas Network and Cadent, forms part of a wider drive to scale up the use of hydrogen on the UK gas grid. In the Prime Minister’s recently launched Ten Point Plan for a Green Industrial Revolution, Boris Johnson announced headline goals to develop the country’s first ‘hydrogen neighbourhood’ in 2023 and the first ‘hydrogen town’ before the end of the decade.
Business Green 16th Feb 2021 read more »
The Gateshead houses will run on tanks of regular hydrogen provided on site, rather than via the local gas grid which still uses fossil fuel gas. The first homes in the world to use green hydrogen through a local gas grid will move ahead in Fife, Scotland by the end of next year.
Guardian 16th Feb 2021 read more »