I See Electromagnetic Fields!
- Mar 28, 2020
Rotating mass is good to overcome the inrush.
But it is bad also because slow to respond. An inverter + battery can correct in ms.
More the mass, slower the response. So it is good for base power plants. But fast reaction power plants need fast response.
If you have a rotating generator, the RPM (for at least some types) corresponds to 60 Hz line frequency.
When you throw a big load on it, it pushes out current but starts to slow down. So governor gives the diesel more fuel, or valve lets more water into turbine.
For a pelton wheel (a type of high head turbine), nozzles spray stream of water through the air against buckets. Adjustable nozzle can control flow while still producing same velocity.
I'm less clear on how low head turbine vary their water consumption with load. Water flowing through blades seems like almost fixed displacement.
For pumped hydro, need variable volume of pumping (which could be multiple pumps turned on or off.) With lots of PV, would want pumps running and varying their volume to match excess production.
Of course the grid has multiple rotating generators, and they have to be in sync. At least some are excited by the grid and push power into it. Not sure how close GT PV inverters behave to that.
The grid generally didn't have a problem, if not overloaded, before PV. It seemed to be able to handle load variations. Shouldn't be that different with PV, except more rapid swings as a cloud moves over L.A. with PV on all roofs.