A cold battery for wind energy
The EU-funded project 'Grid architecture for wind power production with energy storage through load shifting in refrigerated warehouses' (Night Wind) aimed to use refrigerated warehouses as giant batteries for wind energy. In this way, all electricity produced at night through windmills across Europe would be stored and then released into the electric grid at peak hours during the day. Because wind energy is produced at random times, it makes sense, both energy wise and environmentally, to store it during the night so as to provide steady electricity during daytime peak hours. To achieve its aims, Night Wind investigated the use of existing technology and upgraded it with systems to control temperature in the warehouses. This is especially important in cases of 'island operation' where surplus energy is delivered to the grid and where windmills are located faraway from cold stores. The project team began by researching the economic benefits of storing wind power. It then used powerful simulation tools and worked on the design of control strategies to realise the proposed system. This was followed by design and modelling of infrastructures for island operation of wind energy, including the required software. Night Wind also had to consider preservation of frozen food products already stored in existing cold warehouses and their coexistence with the new proposed use. It studied legal issues such as licenses and food safety laws, as well as technical issues such as possible temperature fluctuations. Actual tests were undertaken in warehouses, focusing on the quality of food as well. While a full control system could not be realised within the timeframe of the project, Night Wind highlighted the potential of the proposal and produced important research for future projects to build on. The positive effects on energy use, reduction of emissions and increased competitiveness of small and medium-sized enterprises (SMEs) in cold storage facilities could be significant if the technology is eventually exploited.