> Right, I think hydro is about as close to at-scale 24/7 always-on generation as you can get with renewables right now.
There are quite some solar-thermal installations of >100MW, which store solar energy in a thermal buffer to later convert this to electrical power, creating an effective 24/7 stable supply of power, weather permitting.
Couple of years ago I tried comparing the cost of a solar thermal plant with PV solar. Claimed advantage of solar thermal is the ability to store energy as molten salt. The cost differential though means it'd be cheaper to use PV Solar to heat phase change materials.
There are quite some solar-thermal installations of >100MW, which store solar energy in a thermal buffer to later convert this to electrical power, creating an effective 24/7 stable supply of power, weather permitting.