- overprovisioning because it's still cheap enough
- peak shaving with battery storage
- dynamic demand applications, powered by hours of "free" energy, taking them outside the peak demand: car charging, heat and cold buffers (aluminum smeltering, ice buffers for A/C), and lots more that will prop up
- mix of sources. Solar+wind is more reliable than either solar or wind.
- geothermal
- interconnected grids. The wind is always blowing somewhere.
- Renewables+batteries are already cheap enough for a few hours storage
- Flow batteries can go overnight to weeks
- Synthetic fuels (i.e. hydrogen, or synthetic hydrocarbons made with green hydrogen & CO2 captured from the air) can be stored indefinitely and transported globally
https://www.energy.gov/eere/water/pumped-storage-hydropower
It is also popular in Europe.
Currently the shortfall is dispatched with conventional sources (mostly gas, coal and nuclear similar amounts). Battery prices continue to fall. Also new large storage facilities are coming online, such as compressed air which promise tens of Gigawatt-hours of storage at prices below battery. So that's the long term plan.
Aluminum smelters do everything in their power to avoid a situation where they lose power for more than a few hours and their pots freeze.
So you can dispatch for a few hours, but it adds enormous operational complexity if you can’t depend on 24x7 power.
In that case, even if storage of electricity is expensive. At some it will be cheaper than burning fossil. Nobody really knows how new nuclear competes with storage.
If there is no price on CO2 (and now other regulations that limit fossil), then renewables just have to compete with fossil on price.
We know we cannot yet store energy from wind and solar. So they are fine as contributors to the grid, but cannot really take the "power anytime" burden. Yet they are installed in huge numbers. What happens after a "critical mass" is installed?
Is it:
- Power companies are gaming the current environment, where marginal renewables are cheap, and take preference over fuel-driven plants (fossil or nuclear)?
- Is it a long bet on storage becoming cheap enough that renewables+storage (batteries?) are viable?
- Something else?