Hydrogen powered trains are in the news at the moment. They are being promoted as a means of making railways less dependent on carbon as a fuel. The idea is that the unwanted electricity from wind generation can be electrolysed and used as fuel in fuel cells. The system is being trialled in Germany on a new train, the i-Lint, and in the UK on a converted class 321 multiple unit train dating from the late 1980s.
There are at least four snags.
As for the unwanted hydrogen, there is a simple solution - feed it into the gas grid. This would have to be in defined areas as combustion requires different air:gas volume ratios than are used for natural gas. The hydrogen can then be used for on-site electricity generation in combined heat and power systems, which results in minimal waste of energy.
There are at least four snags.
- The hydrogen has to be compressed and stored in heavy tanks.
- Overall energy efficiency is about 27%.
- Fuel cells have a limited life.
- Cost.
As for the unwanted hydrogen, there is a simple solution - feed it into the gas grid. This would have to be in defined areas as combustion requires different air:gas volume ratios than are used for natural gas. The hydrogen can then be used for on-site electricity generation in combined heat and power systems, which results in minimal waste of energy.
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