The only thing that turns in this conversation is Earth and solar output in December would slightly differ.
Dams provide most parts of the globe a lot of seasonal storage. It takes the same water if they average 10% over the year or 5% over 9 months and 25% over 3. Similarly, locations for wind farms often vary in the season they provide the most power. So the economic maximum around high solar productivity ends up compensating for it’s lower winter output.
Is this true? I think it's the opposite, that dams and pumped hydrostorage of energy works in a few areas where the geography supports it, but (for example) in the plains of the USA it's not really possible.
Why haven't we built a huge solar farm around the Hoover Dam to pump water back up to Lake Mead insted of letting it flow downstream.
Given how oversubscribed the river water already is, how the river flow rate is steadily diminishing due to increasing temperatures, and the politics involved, even a small or temporary additional reduction in downstream flow would encounter huge opposition.
The northeast and northwest has an abundance of water. Managing total water usage is a large problem for the southwest but there’s many opportunities to do things like evaporation reduction.
Looking at the US most of it is family close to large scale hydropower, except Florida, but it’s a little under 7% of annual power nationwide. https://www.eia.gov/todayinenergy/images/2011.06.10/hydro_pa...