Home » Case Studies » How RTE is using Li-ion energy storage to build grid flexibility
Greater flexibility will enable RTE to adapt to the changing power landscape, optimize its assets and maximize use of renewable energy. Because wind and solar farms are often located at the edge of the grid, energy can be lost when transmission lines do not have enough capacity to carry their full output.
Rather than upgrading the grid, RTE is using the RINGO project to explore the innovative approach of using digitally controlled energy storage to absorb and release energy simultaneously at different sites located up and downstream of grid bottlenecks. This way, renewable energy can be managed by RTE’s pilot system and thereby delivered, overcoming locations of limited peak transmission capacity. This will not interfere with competitive energy trading markets, providing flexibility without breaching RTE’s regulatory requirements.
Ringo project goals :
The RINGO project calls for deep charge and discharge cycles of up to 70 percent of the energy storage capacity. This is challenging as batteries age more quickly when used for deep cycling.
An additional requirement after the first three years is for the batteries to provide grid services such as frequency regulation. This requires shallow and frequent cycling as well as the ability to respond within milliseconds. Therefore, the ESS needs to be flexible to adapt to changing charge and discharge patterns and potentially stack multiple different services at once.
Saft and its consortium partner Schneider Electric are delivering a turnkey system with 12 of Saft’s Intensium® Max 20 High Energy 1500V containers, six inverters and four high-voltage transformers. Each container provides 2.5 MWh energy storage and 1.2 MW power with control, thermal management, and safety systems in a standard 20-foot shipping container. These are designed as building blocks to create large-scale installations up to 100 MW and provide best-in-class performance across energy density, energy efficiency, lifetime and performance. They are manufactured at Saft’s plant in Bordeaux, France.
To size the ESS, Saft carried out extensive modelling of different operational scenarios. Special attention was given to the system’s energy efficiency, considering AC/DC conversion efficiency, thermal behaviour, cooling and heating efficiency and auxiliary energy consumption. In addition, Saft provided an exhaustive environment and life cycle assessment study, enabling RTE to evaluate the global environmental performance of the RINGO project.
Flexibility is also supported by the modular nature of the ESS as RTE could move some or all the ESS containers to other locations if needed.
Key benefits :