Nice!

I didn’t agree that you threw wind and hydro in the same bag as solar, but that seems a detail relative to the gem of your article.

The flywheel is a humble but brilliant, relatively clean method of storing energy of course.

Solar is the key to survival, that is the extraterrestrial primary energy source of all things, so the only one truly safe to use.

One day we might have a solar powered world grid which would remove energy storage requirements, but until then, we need some seriously capable energy storage facilities to keep the energy flowing where the sun isn’t shining.

I had forgotten all about flywheels until your article (most of my thinking life, of around 50 years to date).

It is actually really important to make sure we don’t fall into the fatal trap of powering significant flywheels from anything except solar though.

The gyroscopic forces of significant flywheel energy processing would absolutely have an accumulative effect on the rotation, and thus also the orbit of Earth.

The energy being processed coming from the external power source of the sun should have no net effect.

However the energy coming from within Earth, due to the energy being used having to translate to a reduction of total rotating mass, would translate to gyroscopic forces acting against the natural motion of Earth, slowing its rotation, widening its orbit around the sun.

It would not be long before we would be on a trajectory moving away from the sun, with no means of correcting.

If in doubt, check out the reason we add more leap seconds to nuclear clocks with each passing year.

We are already slowing down, which means we are already changing trajectory.

It could even be we could arrange gyros like those of your article in such a way as to correct, but again, only if our energy source is external, in other words, the sun.