South Australia, which generated 60% of its electricity with renewables last year, is installing synchronous condensers to provide some kind of grid stabilisation. (The current conservative government is aiming for net 100% renewables by 2030 and 500% by 2050.)
Technical question: my understanding is that the frequency of an electrical grid is literally related to the RPM of turbines providing power, and that over/under frequency are related to supply and demand.
https://www.brighthubengineering.com/power-plants/45640-grid...
If we hypothetically had a grid that was 100% solar, presumably there'd no longer be any spinning turbines. At that point, would the grid frequency be completely synthetic? How would supply/demand impact the frequency in that case?
Edit: partially answered here ("smart inverters):
https://www.energy.gov/eere/solar/solar-integration-inverter...