Japan's New Energy and Industrial Technology Development Organization (NEDO); the Ministry for Economics, Labour and Transport of Niedersachsen of the Federal Republic of Germany; EWE-Verband, an association managing the electric power supply to 17 districts and four cities in Niedersachsen, and EEW Holding have agreed to jointly implement a demonstration project on a large-scale hybrid battery system. The demonstration project will be launched in Niedersachsen, which has been actively introducing renewable energy, particularly large-scale wind power, in recent years. The project aims to build a large-scale hybrid battery system using lithium-ion batteries and NAS batteries that can stabilise the distribution grid, and thereby control the electric power supply and demand balance, by charging and discharging storage batteries. Another aim is to establish a new business model for electricity trading using the battery system. Germany aims to shift more than 80 per cent of its domestic electric power demand to renewable energy by 2050 under its Energiewende energy transition policy by actively introducing renewable energy resources such as wind and solar power. Niedersachsen, a state in north western Germany, is the country's largest wind energy provider as of 2015. The demonstration project will be carried out over a three-year period from April 2017 to March 2020 in Varel, Niedersachsen, to build a large-scale hybrid battery system that can stabilise the distribution grid, and thereby control the electric power supply and demand balance, by charging and discharging storage batteries. Another aim is to establish a new business model for electricity trading using the system. Moreover, the project plans to collaborate with Germany's ‘enera’ project