Storage technologies are becoming increasingly important in order to compensate fluctuating energy from variable renewable energy sources, particularly from wind- and solar power generation. These two sustainable forms of energy have a so-called stochastic energy flow, that means the predictability of the amount of energy generated as a result of local weather development cannot be determined in advance and is relatively inaccurately predictable by weather forecasts. Consequently, energy storage technologies of various kinds are becoming progressively more significant to ensure network stability.
Additionally, the trend towards decentralized energy supply is increasing. Whether with island solutions (see Fig. West Coast Power Energy Efficient House) or network solutions, decentralized energy supply systems require appropriately sized energy storage units. These storage units perform in a bidirectional way and hence fulfill a dual function:
- Absorption, intermediate storage and distribution of the energy produced for own consumption as well as for its sale at correspondingly high purchase prices (power exchange)
- Storage of surplus useful energy in the occurrence of an overcapacity thus has a stabilizing effect on the power transmission network and therefore is in the interest of the network operators. In addition, it is cost-optimizing (reduced energy purchase price may be lower than production cost)