What are the requirements for energy storage power supply

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.

As a consequence, to guarantee a safe and stable energy supply, faster and larger energy availability in the system is needed. This survey paper aims at providing an overview of the role of energy storage systems (ESS) to ensure the energy supply in future energy grids.

DC connection The majority of energy storage systems are based on DC systems (e.g., batteries, supercapacitors, fuel cells). For this reason, connecting in parallel at DC level more storage technologies allows to save an AC/DC conversion stage, and thus improve the system efficiency and reduce costs.

Requirements: Energy shall be available in the short and long term to compensate any mismatch between energy production and consumption. Ideally, during over-production the energy shall be stored, to be re-used during over-consumption conditions. Proposed solutions shall be implemented at very large-scale.

In principle the energy can be stored indefi nitely as long as the cooling system is operational, but longer storage times are limited by the energy demand of the refrigeration system. Large SMES systems with more than 10 MW power are mainly used in particle detectors for high-energy physics experiments and nuclear fusion.

The advantages of such testing setup are clear: the energy storage systems can be tested under realistic conditions, taking into account the grid complexity. This is particularly important when dynamic studies are involved.