Combined long-term and short-term access storage for sustainable energy system

Although popular renewable energy sources based on solar or wind energy conversion are renewable, environmentally friendly and increasingly competitive in terms of cost, their intermittent availability results in problems. The output of power depends on the given solar radiation or wind speed, and the load following characteristics are poor. Local and wide area storage systems are discussed as a solution. The proposed concept consists of a stochastic source that is coupled via a DC bus with multilevel access storage and a grid interface. The multilevel access storage is a combination of long-term and short-term access storage that allows to compensate for the intermittent availability of power over a wide range of time constants. It is discussed how the coordinated operation of source and multilevel access storage can support the large-scale integration of renewable distributed sources into a sustainable energy system