Power-to-X, an essential concept for the success of the energy transition.

The excess electrical power can be converted into other forms of energy for storage and reconversion. Direct current electrolysis can be used to produce hydrogen which, in turn, can be converted to methane (CH4) by methanation. Another possibility is to convert hydrogen, as well as CO2, into methanol. Both of these fuels can be stored and used again to generate electricity, hours to months later. This means that large amounts of energy can be stored for long periods of time, which is ideal for seasonal storage. This could be particularly useful for systems with high renewable penetration, as many regions exhibit significant seasonal variability in solar, wind and hydroelectric generation. Dedicated battery storage on the network is not generally considered a power-to-X concept.