Storing solar power for the night isn't hard. It has been possible to do so for decades with concentrated solar power (CSP). You heath up salt directly with the

Storing solar power for the night isn't hard. It has been possible to do so for decades with concentrated solar power (CSP). You heath up salt directly with the sun. The hot salt can then drive steam turbines at night. CSP has been dying for years however because Photovoltaics are cheaper. However, this is largely due to regulation. Solutions are picked based on price per kWh. CSP cannot compete on that with Solar cells. However today government have started modifying regulation so that a premium price is paid to those which can deliver power at night. CSP projects then become competitive since unlike solar cells they can deliver power at night. In the past CSP projects delivered power the whole day. Now they are increasingly only delivering power at night, thus getting the premium price. This goes to show that to get desired development in renewable energy it is crucial to get regulation right. Until now, regulation has not properly rewarded projects which can deliver power on demand. However once that is in place, thermal and cryogenic storage of power will become competitive and be built.