[bulldoa]

> It's a problem with a thousand solutions. It's just a matter of getting costs down and production up

Can you source this? I heard of molten salt, gravity storage etc... but I have not read any paper stating we can scale those solution to 50% or even 20% of our current grid usage

[beat]

Have you read a paper saying we can't scale those solutions? Can you think of a rational reason they can't be scaled?

The problem isn't "can't". Storing energy is trivial. The problem is cost. How much storage is required, and how much will it cost to build it, and how much will that make the total cost of a new energy system?

All this "can't" stuff is, frankly, reactionary bullshit by some very emotional people who are rather in love with the idea of nuclear energy. That's why you never see hard numbers attached to it.

[manfredo]

Storing energy is not at all trivial. You want hard numbers? Here are the hard numbers. California's largest energy storage facility, still under construction, is set to have 300MWh of capacity. By comparison, the Diablo Canyon nuclear plant generates 300MWh of electricity every ten minutes. The largest energy storage facility in the world, still under construction in Utah, is set to store between 1-2 GWh of energy. This is still less than what the plant generates every hour.

Electricity to gas conversion has terrible efficiency. 30-40% for the electrolysis and Sabatier process, and then ~50% efficient for the gas combustion engine. Net efficiency is in the 20-25% range. Hydroelectric storage is geographically dependent. Most of the US is in flat terrain.

California said they would do solar and wind plus storage. Then they realized storage was not possible, and they used fossil fuels instead. Similarly, Germany closed down their nuclear plants, saying they'll build intermittent renewables plus storage. And then they ended up building fossil fuel plants when they realized storage could not fulfill the base load they lost from closing nuclear plants.

[labawi]

Why not store hydrogen? Estimated round-trip efficiency is approximately 40%. Storage in underground caverns / mines.

If most of the energy consumption is supplied directly, the storage part need not be overly efficient as long as it can cover the slack. 40% seems good enough. Even 20% is workable, if need be, just need to over-provision enough PV / wind and the over-provisioning itself significantly reduces needed storage.

If combined with capacious long-distance electrical grid (e.g. HV DC), load scheduling, high-uptime offshore wind, some PV in deserts, maybe thermo-electric solar, some batteries for rapid load following, etc, we really can supply enough power even with 0 coal, gas and nuclear power plants, and it wouldn't even bankrupt us. All we need is will. The technology is already sufficient and with improvements it won't be even that hard.

[opo]

Trying to rely only on intermittent power sources has huge storage requirements due to weather along with daily/seasonal variation. If grid energy storage was a simple problem it would have been done decades ago.

For example, one estimate is that for Germany to rely on solar and wind would require about 6,000 pumped storage plants which is 183 times their current capacity:

>...Based on German hourly feed-in and consumption data for electric power, this paper studies the storage and buffering needs resulting from the volatility of wind and solar energy. It shows that joint buffers for wind and solar energy require less storage capacity than would be necessary to buffer wind or solar energy alone. The storage requirement of over 6,000 pumped storage plants, which is 183 times Germany’s current capacity, would nevertheless be huge.

https://www.econstor.eu/bitstream/10419/144985/1/cesifo1_wp5...

[tekknik]

Land use becomes a real problem with some solutions, so yes it can be a “can’t”

[labawi]

You don't need to use solutions that don't work or scale. You only need to have those that do, and there are.

They just cost more than market rates.