They also fail catastrophically if they snap. The biggest thing holding back flywheel storage is the danger of spinning something really really big, really really fast. Like if a flywheel that powers a building fails, and it can due to material weakness, it will take out the entire building. On a household scale, you don't want shrapnel flying around at more than 10000 RPM. For safety they're buried underground, and have other safety features to stop safely but that increases cost. I think they're mostly used for grid regulation.
I think they're mainly for short term regulatory storage, since they can be charged and discharged quickly. I don't think anyone wants to store an entire city's power in flywheels.
They also fail catastrophically if they snap. The biggest thing holding back flywheel storage is the danger of spinning something really really big, really really fast. Like if a flywheel that powers a building fails, and it can due to material weakness, it will take out the entire building. On a household scale, you don't want shrapnel flying around at more than 10000 RPM. For safety they're buried underground, and have other safety features to stop safely but that increases cost. I think they're mostly used for grid regulation.
Flywheels are for grid level storage, which is the primary problem holding back renewable sustainables.
Still a lot less effective than just building a pellet reactor.
I think they're mainly for short term regulatory storage, since they can be charged and discharged quickly. I don't think anyone wants to store an entire city's power in flywheels.