"Once we have better batteries for storage, what problem do we have left that requires hydrogen to solve?" Well... also storage. The cheaper it becomes to stor

"Once we have better batteries for storage, what problem do we have left that requires hydrogen to solve?" Well... also storage. The cheaper it becomes to store energy as hydrogen the better. The fact that the overall process is less efficient than battery storage does not mean hydrogen will not be used. The amount of energy that can be stored in batteries is relatively small, and there are only so many viable hydroelectric storage sites. We'll need more than one way to store energy on the grid level. Hydrogen also enables countries to export energy. For instance, quite a few oil-producing countries receive lots of sunshine. Moving away from oil, they could produce hydrogen using solar power and export it elsewhere in the world. That might be less efficient than transporting the electricity directly, but much easier politically: just imagine building a power line from Saudi Arabia to Germany. How many countries would have to collaborate to make it work? Edit: hydrogen can also replace other substances in process engineering. For instance, there are ways to produce steel with hydrogen instead of carbon-based fuels as a reducing agent.