With the increasing growth of global power demand and the rapid development of renewable energy, the security of the power grid becomes more and more important. Power failure or shortage will have a negative impact on any economy. Energy storage system(ESS) is considered an effective solution to make any grid more reliable and more flexible.
ESS compensates for the shortcomings of intermittent and instability of solar power and wind power. It stores energy generated irregularly and intermittently by solar/wind power generation systems. Through charging and discharging methods, it quickly responds to frequency-regulated and voltage adjustment commands, stabilizes renewable energy output, minimizes output fluctuation, improves power quality, deals with grid stability problems caused by large-scale renewable energy grid connection, improves grid stability.
By charging at off peak loads and discharging at peak loads ESS provides peak cut/shift and reliable and fast frequency response to the grid. It relieves the impact of peak load on the power grid, reduces the investment cost of upgrading the power grid and the energy loss during transmission and distribution. The overal operation efficiency of electricity equipments is improved.
As electricity is stored during off peak period but used during peak hours, ESS can balance the load demand and reduce electricity costs. When the grid fails, as an emergency power supply ESS can ensure normal power supply.