hackertourist writes "A novel type of electricity storage was recently added to the New York power grid. The unit, supplied by Beacon Power, uses flywheels to store energy. This system is intended to replace gas turbines in supplying short-term peaks in power demand (also known as frequency regulation). It can supply up to 20 MW, using 200 flywheels." If you can't afford a 200-flywheel system, you can always get a racetrack-ready Porsche 911 GT3 R Hybrid, which has a single energy-storage flywheel that can give you a 160 HP burst of power when you need a little extra oomph.