points by bluGill 2 days ago | 0 comments
> we still need a rotating chunk of steel to stabilise the grid
No we don't. Battery systems can stabilize the grid. You need inverters that are designed for this, but it isn't hard to make an inverter that will set then grid frequency and force it correct. You want most inverters to follow the source, but something needs to set it.
Most rotating steel isn't setting grid frequency either, an induction motor follows the frequency of the grid, and generates power if it is rotating faster than the grid frequency. (this is much more complex, but close enough for a quick comment).
[–] Roark66 2 days ago
[–] mphillips 1 day ago
As I write this from South Australia, our grid (up to 3GW of demand, ~2 million people) is more than entirely powered by rooftop solar alone (https://explore.openelectricity.org.au/energy/sa1/?range=1d&...). The only synchronous generation, gas turbines , is providing just under 4%.
This is a regular event outside of the winter months, and has been for some years now. South Australia has a mixture of solar, wind, and gas generation, with some large batteries as storage.
[–] Stevvo 2 days ago
The Canary islands do not have space for a lot solar. There is some empty desert on Fuerteventura, but the other islands all flat ground is already used.
>No we don't. Battery systems can stabilize the grid. You need inverters that are designed for this, but it isn't hard to make an inverter that will set then grid frequency and force it correct.
I know in theory we don't, but in practice there is no such real grid anywhere in the world that would run on large percentage of solar. So it seems we do.
I'm talking about real grid as something that powers at least thousands of households. Not a compound with a dozen buildings.
Take Canary Islands for example. They are an ideal environment to setup a 90% solar and battery grid. They have a great climate and size well suited to this. But they still run thermal plants.
Why? Because no one has successfully showed a largish scale frequency regulation/stabilisation with inverters.
See a writeup about the Texas outage a year or two ago to understand how fragile grids with too large percentage of semiconductor sources are compared with rotating masses.