Green hydrogen : hype or hope ?
Green hydrogen has been touted as the answer to a range of clean energy problems in a net-zero grid , from heating homes to fuel for peak power plants .
By Rachael Burnett
But some experts have warned this was hype and its true scope would be limited to replacing the 9mt / year of grey hydrogen used by industries in the EU . Grey hydrogen is produced with fossil fuels , while the green version is produced by electrolysis using renewable power sources .
The EU recently boosted its previous green hydrogen target of 40 GW by 2030 with an additional 10mt / year domestic production and 10mt / year imports . The president of the EU executive , Ursula von der Leyen , also announced a EUR 3bn “ European Hydrogen Bank ” to help fund its development .
While some have welcomed this news as bringing necessary support to a vital component of the energy transition , others have criticised it as misplaced hype spurred on by lobby groups underpinned by fossil fuel companies .
“ I don ’ t think green hydrogen is the answer to any problem other than decarbonising grey hydrogen , which is used to make fertiliser , petrochemicals and some industrial processes ,” says David Cebon , professor of mechanical engineering at the University of Cambridge and founding member of the Hydrogen Science Coalition , a group of independent academics , scientists and engineers .
“ It ’ s all grey hydrogen and that needs to be turned green straight away . There should be strong policy to do this .” Using green hydrogen to decarbonise steel manufacture was another possible market . “ The reason there ’ s so much hype around green hydrogen is the fossil
22 fuel industry , it ’ s pushing hydrogen ,” Cebon says . “ Green hydrogen has become not the means to the end but the end itself . The energy transition strategy used to be : ‘ we ’ ve got to decarbonise our energy system ’ but now it ’ s become : ‘ we ’ ve got to make 40 GW of green hydrogen by 2030 ’.”
“ But most people are talking about hydrogen as a fuel for which it has poor characteristics . For heating it ’ s extremely inefficient and very expensive , it ’ s not good for trucking and doesn ’ t make any sense at all for peaker plants ,” Cebon says , pointing out that converting electricity into hydrogen and then using it for power generation “ throws away ” 70-80 % of its energy content .
Other forms of storage should be developed , such as pumped hydropower , batteries and liquid nitrogen , he adds . “ You pay to generate energy and if you throw away 70 % of it then it costs three times more .” He estimates the UK would need 40 times its current offshore wind capacity to power a hydrogen system for domestic heating , compared with six times more for electric heat pumps .
Injecting hydrogen into the gas grid was also not effective because it has a lower energy content than natural gas , “ meaning if you inject 20 % hydrogen you would only reduce CO2 emissions by 6 %”, he says . “ It hardly helps and requires a vast amount of hydrogen to be generated , you could achieve that same 6 % reduction in emissions by running boilers more efficiently .”
Montel Magazine 3 – 2022