Producing hydrogen from variable renewable electricity (VRE) could be the ‘missing link’ in the unfolding transition to a decarbonised global energy system, a newly released report argues.
Published by the International Renewable Energy Agency (Irena), the study explores the production of hydrogen from renewables using electrolysers – devices that split water into hydrogen and oxygen using electricity.
The authors suggest that such a solution could channel large amounts of renewable energy from the power sector into sectors such as freight transport, buildings and industrial heating, for which electrification, and decarbonisation, would otherwise be difficult.
In fact, Irena notes that there is currently no economically viable option to reduce the carbon emissions produced by around one-third of the energy sector.
“Combustible fuels remain critical to transport and industrial practices from aviation to refining, where electrification is not suitable. This could make hydrogen from renewable energy the missing link in the transformation of the global energy system.”
Titled ‘Hydrogen from Renewable Power’ the report states that the global energy system will have to undergo a profound transformation from fossil fuels to renewable energy to achieve targets set out in the Paris climate agreement.
In the process, the role of VRE is expected to grow materially, while electricity’s share of total energy consumed by end-users is likely to increase to 40% in 2050, from about half that level in 2015.
Electrolysers could help integrate VRA into power systems, as their electricity consumption can be adjusted to follow wind and solar power generation, making hydrogen a source of storage for renewable electricity. “Thus, they offer a flexible load and can also provide grid balancing services (upwards and downwards frequency regulation) whilst operating at optimal capacity to meet demand for hydrogen from industry and the transport sector or for gas-grid injection.”
The clean hydrogen produced, meanwhile, could be deployed in decarbonising a range of energy end-uses, including transportation using fuel-cell electric vehicles (FCEVs).
The report describes FCEVs as complementary to battery electric vehicles (BEVs), owing to the fact that the vehicls are able to overcome some of the current limitations of batteries, such as weight, driving range and refuelling times.
The authors believe that FCEVs have near-term potential in truck and bus markets, but also highlight commercial fuel-cell deployments in the rail sector, as well as research and demonstration programmes in the marine and aviation sectors.
“FCEVs provide a low-carbon mobility option when the hydrogen is produced from renewable energy sources and offer driving performance comparable to conventional vehicles,” the report adds.
Hydrogen, which is currently mostly produced using natural gas, is also widely used in several industrial sectors, such as in refineries, ammonia production and bulk chemicals. “Hydrogen from renewables could replace fossil fuel-based feedstocks in high-emission applications.”
Likewise, the report suggests that hydrogen from renewable sources could be injected into existing natural gas grids, up to certain thresholds, to reduce natural gas consumption and emissions heating buildings.
The authors argue that “the technologies are ready”, but that policy support will be necessary to achieve the scaling-up necessary to ensure the economic viability of hydrogen as a long-term enabler of the energy transition.
“The role of hydrogen from renewables has to be viewed as part of the broader global energy transition. This means integrating hydrogen into decarbonisation scenarios and giving it due consideration as an option in energy system models,” the report concludes.