Li-ion and flow batteries can also provide market oriented services. The best location of the storage should be considered and depends on the service. Energy storage can play an essential role in large scale photovoltaic power plants for complying with the current and future standards (grid codes) or for providing market oriented services.
In addition, considering its medium cyclability requirement, the most recomended technologies would be the ones based on flow and Lithium-Ion batteries. The way to interconnect energy storage within the large scale photovoltaic power plant is an important feature that can affect the price of the overall system.
Energy storage requirements in photovoltaic power plants are reviewed. Li-ion and flywheel technologies are suitable for fulfilling the current grid codes. Supercapacitors will be preferred for providing future services. Li-ion and flow batteries can also provide market oriented services.
When photovoltaic (PV) systems take a larger share of generation capacity i.e. increase in penetration, increasing system flexibility should thus become a priority for policy and decision makers. Electrical energy storage (EES) may provide improvements and services to power systems, so the use of storage will be popular.
Nonetheless, it was also estimated that in 2020 these services could be economically feasible for PV power plants. In contrast, in , the energy storage value of each of these services (firming and time-shift) were studied for a 2.5 MW PV power plant with 4 MW and 3.4 MWh energy storage. In this case, the PV plant is part of a microgrid.
Nevertheless, flywheel energy storage are rarely found in current large scale PV power plants projects. Inertia emulation, fast frequency response and power oscillation damping requirements are strong candidates to be included in the future grid codes.