Dalian flow battery energy storage station is the largest and most powerful worldwide

The 100 megawatt Dalian Flow Battery Energy Storage Peak-shaving Power Station was connected to the grid in Dalian China on Thursday. It will be put into service in mid-October, sources in the Chinese Academy of Sciences have stated.

The energy storage project has the technical support of Professor LI Xianfeng’s group from the Dalian Institute of Chemical Physics (DICP) attached to the Chinese Academy of Sciences. The company that built the system and integrated it into the grid was Rongke Power Co. Ltd.

It can serve thousands

The Dalian Flow Battery Power Station project was approved by the Chinese Energy Administration in 2016. This is the first national, large-scale, chemical energy storage demonstration project approved so far. It will eventually produce 200 megawatts (MW)/ 800 megawatt-hour (MWh) of electricity.

Based on China’s 2 kWh per capita electricity consumption, the first phase of on-grid delivery will be focused on 100 MW/400MWh, which can deliver electricity in a continuous flow to 200,000 residents. This would reduce pressure on the power supply during peak periods and improve the power supply reliability in the southern areas of Dalian.

How the station helps

Energy storage technology can help power systems achieve the strain and response capability that is required after large-scale access to the power grid. It can also be an important part of facilitating the use of renewable energy. This is key to helping China reach its carbon peak, and carbon neutrality goals. But those energy goals a dependent on being able to access energy when there are variations in the wind and sunlight.

The Dalian Flow Battery Energy Storage Peak-shaving Power Station, which is based on the vanadium flow battery energy storage technology developed by the DICP, will serve as Dalian’s “power bank”. It will play a key role in “peak cutting and valley filling” across the main power system. This will help Dalian make use of renewable energy, such as wind and solar energy.

Using Vanadium

During the grid load valley period, renewable energy sources will be used to charge the stations batteries by converting electrical energy into chemical energy which then stored in the batteries. At some point when the energy use on the grid reaches peak power, the chemical energy is then converted back into electricity and delivered to the users.

The power station uses vanadium ions of various valence states. Chemical energy and electrical energy are converted back and forth through a redox reaction of the ions, in positive and negative electrolytes. This allows for large-scale storage and then the release of electrical energy.

The benefits

There is a long list of benefits to this technology, as related by the DICP, and shows promise in large-scale energy storage applications. The process is safe, has good reliability, large output power and storage capacity, long life, good cost performance and use of recyclable electrolytes and environmentally friendly.

There is the additional benefit that this technology can work with conventional thermal power, nuclear power and other power sources, providing for those times of intermittent power and offsetting peak usage and frequency for the power system as well as improving flexibility.