This opinion piece appeared first on the ETH-Zukunftsblog.
Hydrogen as the main energy carrier would delay decarbonization, says Anthony Patt. We should directly replace fossil energy with renewable electricity wherever possible.
Hydrogen for ground transportation and heating is a bad idea
Ambitions to make hydrogen a key energy carrier for a climate friendly future are misguided, says Anthony Patt. Wherever possible, including ground transportation and heating, we should replace fossil fuels with the direct use of renewable electricity.
To save the climate, the world needs to stop using fossil fuels by mid-century. We are finally headed in the right direction. Nearly all new power-sector investment is going into renewable energy sources. Battery electric vehicles (BEVs) are becoming popular. Most new buildings are being built with non-fossil heating systems. The pace of change needs to accelerate, and stronger climate policies are required. Yet one of the most serious threats to all of this is currently masquerading as clean energy’s friend: hydrogen.
The wrong carrier of hope
Hydrogen is an energy carrier, like electricity, not an energy source. We can produce it three ways. Grey hydrogen, currently accounting for nearly all hydrogen used, is obtained from methane, in a process that generates substantial CO2 and fugitive methane emissions. Blue hydrogen is like grey, but with carbon capture and storage to reduce CO2 emissions. Unfortunately, fugitive methane emissions and process inefficiencies lead even blue hydrogen to have higher greenhouse gas emissions than whatever oil and natural gas it might replace.
Green hydrogen is made from water, using renewable electricity for electrolysis. It generates no direct emissions and is the only climate friendly option. The problem with green hydrogen is that, in most cases, using renewable energy directly would be more efficient, less expensive, and demand fewer natural resources and new infrastructure. From a systems perspective these issues are crucial.