Energy Storage - 
Energy storage is generally used in applications were there is a need for (or supply of) non-steady state power. We have performed many trade studies to determine the optimum energy storage systems with one fundamental undeniable conclusion being quite certain: it depends.
We have looked at batteries with standard and exotic chemistries, flywheels of medium and high speed, capacitors (ultra and otherwise), inductors (cryogenic and room temperature), and Superconducting Magnetic Energy Store (SMES). The best energy storage device depends remarkably upon the specific application. For any specific energy storage design, the range of parameters is so great that few additional generalizations are possible. These parameters include initial cost, operating cost, cycle life, recharge rate, discharge rate, maximum stored energy, size and weight.