One tends to think of batteries as the obvious storage devices, with the batteries being recharged when power is produced and discharged when it is needed.. But there is an alternative. Natural gas, or strictly speaking, synthetic natural gas in other words, artificially produced methane/butane. Surplus electricity can be converted into natural gas which is then burned to heat homes or fire electricity generators. Via the Sabatier reaction, hydrogen, generated by the electrolysis of water, is combined with carbon dioxide at high temperatures and pressures to produce methane.
From the Wikipedia article:
The Sabatier reaction or Sabatier process was discovered by the French chemist Paul Sabatier in the 1910s. It involves the reaction of hydrogen with carbon dioxide at elevated temperatures (optimally 300–400 °C) and pressures in the presence of a nickel catalyst to produce methane and water. Optionally, ruthenium on alumina (aluminium oxide) makes a more efficient catalyst. It is described by the following exothermic reaction:
- CO2 + 4 H2 → CH4 + 2 H2O + energy
- ∆H = −165.0 kJ/mol
- (some initial energy/heat is required to start the reaction)
As the cost of solar power falls, we are going to see more and more 'natural gas' and LPG produced from renewable power. Even without that, batteries are in any case falling in cost, and will become ubiquitous in electrical grids. The need for storage will not stop the renewables revolution.