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Comment by tomasphan | Hacker News Reader

I love renewables, but the problem with solar is the lack of inertia (literally). Big spinning masses like steam turbines have an easier time staying on network frequency. Wind turbines better than solar of course so I hope we continue to have diversity there.

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Batteries paired with the right inverters solve this fully. Buys you enough time for powering up backup power in the form of a good old steam turbine (gas or coal powered). No need to keep spinning if they aren't needed.

The good news is that batteries are deployed at almost the same scale as solar now on grids world wide. They can respond in more or less real-time to huge fluctuations in supply and demand and smooth out peaks and dips in those.

The other thing that massive synchronous machines provide is fault current handling. A turbine hall can eat 10x rated current for several cycles. Semiconductor junctions cannot tolerate anything remotely close to this.

Thankfully, synchronous condensers, flywheels and other fossil-free technologies exist.

Thankfully this is one of the easiest limitations to get around technically. Grid forming inverters and inertia markets make this pretty straightforward to solve IMO. Storage is the key thing we need to solve

This is interesting. They can't make AC inverters more reliable than spinning motors? I thought the problem was more about supply not matching demand quickly enough.

Wind has the same problem, because the actual generator is not spinning at line frequency. It has a rectifier plus inverter.

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