Land use of solar prevents it ever getting really cheap. According to the UK solar power portal [1]: "If solar covered one percent of the UK it would meet the country’s entire power demand".
> just build twice as much solar capacity
This would increase the land use from 1% to 2%. That's a huge amount of the country to give over to power production.
It's a reasonable fraction of total roof area, I believe.
But the real problem with the UK and solar is not nighttime but seasonality. No, we need to keep going with the wind buildout and not drop the tidal energy programme.
The UK has a lot of unused land on a percentage basis.
Granted, half of that will be in Scotland and ideally your solar would be further south, but even then, you're probably talking about switching less than 5% of the arable land to solar.
