Comment by chupasaurus
2 days ago
The only thing that turns in this conversation is Earth and solar output in December would slightly differ.
2 days ago
The only thing that turns in this conversation is Earth and solar output in December would slightly differ.
This is where energy mixes and economics come into play.
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.
"Dams provide most parts of the globe a lot of seasonal storage"
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.
There are contracts around how much water needs to flow downstream, so they can't just hold it back like that. California and Arizona both have allocations that they pull from the river downstream of the dam. Mexico too in theory I think, although I don't know if they actually get their allocation any more.
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.
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Hydro generation is pretty geographically limited, but pumped storage only requires two reservoirs vertically separated. If you allow building one of the two reservoirs then there are millions of potential locations.
https://re100.eng.anu.edu.au/global/
It’s not universal, smaller dams don’t have nearly as much storage as large ones but they also produce vastly less power. At the other end the Great Lakes are effectively storing years worth of electricity, and have significant flexibility in delivery.
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...
Because the primary purpose of the Hoover Dam isn’t power generation it’s water management.
0.05% of the world's population live north of the arctic circle. Solar panels don't work for them, but their diesel generators are not a significant portion of the world's CO2.