Energy storage systems (ESS) and microgrids in Brittany islands

Abstract

Sein Island (French Brittany) has an isolated and autonomous network (Fig. 1) that is not connected to the continental electricity grid. It is essential on these islands is to ensure the highest possible degree of robustness and quality-of-service. Currently, power is provided almost solely by diesel generators (gensets) with a high kWh cost and greenhouse gas emissions. Raising the share of renewable energies (RE) in the mix could solve these issues. Thus, 90 kWc of photovoltaic (PV) will be installed in 2017. However, because of renewable energy intermittency, network inertia and gensets features, the deployment of RE may endanger the stability of the power system. To maintain the security of the grid without curtailing PV, Electricité De France has decided to install in 2017 an energy storage system (ESS). A specific simulation tool, developed at EDF R&D, allowed for control algorithm elaboration and ESS sizing. The possibility was shown to completely switch off the gensets and operate the grid solely with the PV and the ESS. The associated issues especially in terms of (i) operation of the ESS and (ii) protection plan are discussed. As a prospect, an experimental validation is planified on our EDF R&D facility of Concept Grid.Fig. 1Single line diagram of Sein Island