"Under baseline conditions, the greenhouse gas (GHG) emissions are around one-quarter that of the currently dominant process for hydrogen production, steam methane reforming (SMR). However, sensitivity analysis shows that GHG emissions may be comparable to SMR under reasonably anticipated conditions. "
I think this type of analysis fails to project the future. GHG emissions from solar cell production will decline as the inputs and processes used to make them begin to use renewable energy.
Green hydrogen decouples H2 generation from hydrocarbons, and industrial uses of H2 will be critical in decoupling more processes and industries from fossil fuels. That's the whole point.
The other part of the abstract suggests that grid energy will be required to buffer intermittent renewables. This argument assumes that it is not possible to design H2 electrolyzers that can rapidly adapt to a change in electrical input, which is simply a relatively straightforward engineering challenge.
I find it hard to believe that the authors of this paper didn't already know all of this.
"Under baseline conditions, the greenhouse gas (GHG) emissions are around one-quarter that of the currently dominant process for hydrogen production, steam methane reforming (SMR). However, sensitivity analysis shows that GHG emissions may be comparable to SMR under reasonably anticipated conditions. "
https://pubs.rsc.org/en/content/articlelanding/2021/ee/d1ee0...