In another thread, someone said that Earth has all the raw materials it needs (except helium) to support many billions. But in this thread, the same person speaks of insufficiency of lithium. And another worries about rare-earth shortages.
In the other thread, someone was unconcerned about the land area spent on humans and their foods. But in this thread the same person claims that sites for pumped-water storage — even when the ocean is used as the lower reservoir — are too scarce due to land use by humans.
Is there an inconsistency here?
Can
Pumped-storage hydroelectricity handle the energy storage problem? The round-trip efficiency is 85% or more; and the systems can even use sea water.
The only big drawback, IIUC, is the high cost of constructing such systems in unsuitable terrain, but those are one-time costs that can be amortized over decades of use.
~ ~ ~ ~ ~ ~
To what extent do consumer electricity prices vary in time to reflect energy availability? Operating battery chargers and pumps during off-peak hours would reduce the meed for storage.
Most of the good sites for pumped storage are either already in use for hydroelectric power; Or are unavailable due to being occupied by residents who are currently getting a lot more out of the land economically than it could produce as a big battery.
Even if we evicted the current occupants of all suitable sites, it still wouldn't provide sufficient storage to cover the intermittency of 100% wind and solar, except in a handful of places with rugged mountains and low population.
Several posts in this thread seems to think that 100% of power is "intermittent", that a proposal is that ONLY stored power be available at some times. But this is NOT the case.
For starters: Wind often blows even at night, when the sun is not shining! Also, hydroelectric power — dams, which provide 7% of U.S.A.'s electrical power — are OPPOSITE from other renewables, in that the water flow can be shuttered when demand is low. There are other forms of renewable energy — geothermal, waves, tides — which, while not yet in widespread use, do avoid the intermittency problem of wind and solar.
And finally, despite opposition and premature closings, 19% of the U.S.'s electricity still comes from nuclear power, and UIAM a large majority of serious environmentalists see nuclear power as part of any environmentally friendly energy program. Do we need to constantly argue against straw-men? (Or straw-girls like Greta Thunberg?
)
