Energy storage to power system

Various application domains are considered. Energy storage is one of the hot points of research in electrical power engineering as it is essential in power systems. It can improve power system stability, shorten energy generation environmental influence, enhance system efficiency, and also raise renewable energy source penetrations.

Energy storage systems allow energy consumption to be separated in time from the production of energy, whether it be electrical or thermal energy. The storing of electricity typically occurs in chemical (e.g., lead acid batteries or lithium-ion batteries, to name just two of the best known) or mechanical means (e.g., pumped hydro storage).

With the advancement of new energy storage technol-ogies, e.g. chemical batteries and flywheels, in recent years, they have been applied in power systems and their total installed capacity is increasing very fast. The large-scale development of REG and the application of new ESSs in power system are the two backgrounds of this book.

As a consequence, the electrical grid sees much higher power variability than in the past, challenging its frequency and voltage regulation. Energy storage systems will be fundamental for ensuring the energy supply and the voltage power quality to customers.

The so-called battery “charges” when power is used to pump water from a lower reservoir to a higher reservoir. The energy storage system “discharges” power when water, pulled by gravity, is released back to the lower-elevation reservoir and passes through a turbine along the way.

The main objectives of introducing energy storage to a power utility are to improve the system load factor, achieve peak shaving, provide system reserve and effectively minimise the overall cost of energy production. Constraints of various systems must also be satisfied for both charge and discharge storage regimes.