Key players in the market are investing in research and development to enhance the efficiency and performance of flywheel energy storage systems. However, factors such as high initial costs and competition from other energy storage technologies pose challenges to. . A flywheel-storage power system uses a flywheel for grid energy storage, (see Flywheel energy storage) and can be a comparatively small storage facility with a peak power of up to 20 MW. Fly wheels store energy in mechanical rotational energy to be then converted into the required power form when required. Unlike electrochemical energy storage. .