Long duration energy storage will be put to use in Germany’s grid, with RedT, a UK-headquartered maker of flow energy storage ‘machines’, announcing an initial 80MWh deployment to the country.

Through a two-phase deal brokered with developer Energy System Management – a subsidiary of WWF Solar – RedT will deliver 1,066 of its Gen 3 tank units to form two 40MWh grid-scale projects in the first phase. The second phase is a much bigger deal, comprising a further 690MWh of projects.

The battery storage systems, based on vanadium redox flow technology in which energy is stored as liquid electrolyte in tanks, will provide Secondary Control Reserve (SCR), aka Automated Frequency Response Reserve, to the grids of Austria and Germany. Unlike the better-known Primary Control Reserve, which is fast-acting frequency response delivered within minutes or less of receiving a signal from the grid and essentially provides short bursts of power, SCR requires four hours minimum energy capacities and longer periods of energy delivery.

In Germany, the market for energy storage systems to provide grid services is more mature than many others, RedT CEO Scott McGregor told Energy-Storage.news today, referencing some 8GWh of SCR capacity already online, for which he said “there are very good revenue streams,” for providing the service.

In many other early stage grid storage markets such as the UK and Australia, the majority of large battery systems are intended to provide just a few minutes of energy storage to balance control voltage. Systems providing SCR are paid for the available power and energy they can discharge onto the grid – or draw from the grid to charge.

“It’s not really storing renewables on the grid,” McGregor said of the shorter frequency response projects of the UK and Australia, whereas “the secondary market in Germany is a full blown four hour market so it will use the full four hours of the system.”