Photo: A typical modern flywheel doesn't even look like a wheel! It consists of a spinning carbon-fiber cylinder mounted inside a very sturdy container, which is designed to stop any high-speed fragments if the rotor should break. Flywheels like this have an electric motor and/or generatorattached, which stores the. Flywheels are relatively simple technology withlots of plus points compared to rivals such as rechargeable batteries: in terms of initial cost and ongoingmaintenance, they work out cheaper, last. In the 1950s, flywheel-powered buses, known as, were used in () and () and there is ongoing research to make flywheel systems that are smaller, lighter, cheaper and have a greater capacity. It is hoped that flywheel systems can replace conventional chemical batteries for mobile applications, such as for electric vehicles. Proposed flywh.