Concentrated Solar Thermal Power
Here is a logical application of solar power that lets it work at night.
This is really just a sophisticated version of something that people use all the time in passive solar power: a heat sink. It has a lot of potential despite the cost quibbles. Remember that cost is only an issue when there are multiple options and enough cash moving around. Lower those ceilings and people will use what remains possible -- and this tech, unlike batteries, doesn't require rare earths or fiddly parts. It uses water and mirrors, which we're not going to run out of.
This is really just a sophisticated version of something that people use all the time in passive solar power: a heat sink. It has a lot of potential despite the cost quibbles. Remember that cost is only an issue when there are multiple options and enough cash moving around. Lower those ceilings and people will use what remains possible -- and this tech, unlike batteries, doesn't require rare earths or fiddly parts. It uses water and mirrors, which we're not going to run out of.