Comment by DanielHB

I work with grid storage battery systems (as a software engineer, so no expert on the physics)

> It's interesting, I've heard lots of tales about how we need the spinning mass to stabilise the grid in way which apparently solar, for example, doesn't.

This is false and a common misconception according to a coworker of mine, having a spinning mass to stabilise the grid is one way of keeping frequency stable, but not the only way. In fact batteries are way better than spinning mass at stabilising frequency. The problem with batteries is that they need a lot of software systems to kick in and kick out of the grid and those can be quite complicated and costly to develop, but once they are in place they will stabilise the grid way better than a giant flywheel.

This is so commonly misunderstood that apparently Australia (where my coworker used to work) had some rules at the central electricity provider agency to enforce certain minimum amounts of spinning mass in the grid. So it seems it can also be a matter of regulations not catching up with technology.