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paulfdietz OP t1_j5cgzp4 wrote

Reply to comment by sweenman22 in Eye-popping new cost estimates released for NuScale small modular reactor by paulfdietz

That's what the storage is for.

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Columbus43219 t1_j5cjdot wrote

Don't bother. They're thinking of powering a city, not a house. I want to go completely off grid at my house too, not gonna happen because my wife thinks the panels are ugly.

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paulfdietz OP t1_j5cku85 wrote

Why is storage not valid for powering a city?

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kkngs t1_j5clhek wrote

Exactly what storage are you referring to?

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paulfdietz OP t1_j5cm5zz wrote

Pumped hydro, pumped thermal ("Brayton battery"), various kinds of chemical batteries, hydrogen. For example.

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prometheus2508 t1_j5cs6qk wrote

Pumped hydro currently has enough storage to supply...1 hour of the US electricity demand.

Getting more pumped hydro means building dams and flooding valleys - an ecological disaster.

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paulfdietz OP t1_j5csu19 wrote

The existing capacity is not relevant, because as long as most power is coming from burning fossil fuels such storage is pointless.

Pumped hydro would be installed off river. It does not require flooding any significant watercourses. The area flooded would be small compared to the area used by other human activities.

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prometheus2508 t1_j5cu09d wrote

Lol do the math and get back to me. Ep = mgh

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paulfdietz OP t1_j5cvka2 wrote

To supply six hours of storage for 600 GW of power with a vertical displacement of 100 meters and water depth of 10 meters, you'd need upper and lower reservoirs with total area of about 3000 km^2. That's a tiny fraction (about 0.03%) of the land area of the United States.

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MasterDew5 t1_j5eli76 wrote

Where are you going to find 750,000 ac. to build a 10 meter deep reservoir with a 100 meter fall? Plus this is using 100% efficiency. When in practice you are lucky to get over 60%. Look up Raccoon Mtn in Tennessee.

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prometheus2508 t1_j5cvtvs wrote

That's a unit calculation. How many 600 GW units do we need?

I've done the math myself, that's why I know it's bullshit.

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paulfdietz OP t1_j5d45nt wrote

600 GW is roughly the average power used by the US grid.

EDIT: more like 470 GW. Ballpark.

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prometheus2508 t1_j5d4gio wrote

600GJ PER SECOND is the average power used by the US electrical grid?!

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paulfdietz OP t1_j5d71un wrote

Average power being put onto the grid, yes, around that.

World average rate of primary energy consumption is around 18,000 GW. This includes thermal input to all sectors: transportation, industry, commercial and not just fuel used for electricity production.

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Columbus43219 t1_j5cut5l wrote

I don't think it's there yet at capacity. The change over would be disruptive and that's a political third rail.

I really wish I could find it, but there was this old video of a guy giving a roadmap plan for cities to use less electricity with no loss of quality of life. He got down to things like how the motors in elevators are so inefficient because of how they get produced. And that's because of how ALL motors get produced to be the standards that we use. (bad paraphrase by me of course)

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