Comment by SoftTalker
2 days ago
"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.
With multiple dams you can release water early at one point in the system and have zero impact on users below the second dam.
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.
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.