Determine which features electricity storage systems on power grids in the French overseas departments would have to offer to more easily integrate wind and photovoltaic energy production



Integrating renewables into isolated island grids like those found in the French overseas departments presents a major challenge. And yet renewables are the key to providing these island communities with greater energy independence and lower energy bills. Grid operators do not currently have the tools they need to cope with more than 20% or 30% of energy from intermittent sources like wind turbines or photovoltaic solar panels. Sometimes they must make difficult choices like cutting renewables producers off from the grid. The Enerstock project focused on finding technical solutions to allow grid operators to better integrate renewables into the energy supply. The goal was to determine the feasibility of a hydraulic pump/turbine storage system, both with and without a battery. The system would of course have to provide a range of smart-grid features—renewable production forecasting and management, demand-response, and frequency support capabilities—to facilitate better renewables integration.


The Enerstock project determined how to optimally combine pumped storage hydro power (PSP) and lithiumion technologies to meet storage system specifications for isolated island grids.



The Enerstock project began with research to analyze the technologies selected and determine their suitability. PSP and Li-ion were deemed optimal. France-based hydraulic turbine manufacturer Mecamidi and Artelia, a hydraulic engineering firm, helped design the plant and choose the most appropriate components. Lithium-ion battery manufacturer SAFT, also based in France, determined the optimal operating conditions for the batteries. Additional clarifi cation of the costs and constraints of such systems further underscored the relevance of the Enerstock project. Simulations were completed to identify the features that would have the greatest impact on intermittent renewables integration. The results were used to develop specifications for government RFPs for wind and photovoltaic generation systems offering storage possibilities for isolated island grids. Studies were also completed to determine the optimal conditions for island grids, both for a medium-power PSP coupled with renewable energy production and for the lithium-ion battery system. Tests carried out on reduced-scale models provided valuable feedback. A preliminary design for a demonstrator PSP on Réunion was assessed under the project and presented to the French national energy agency, ADEME. It will pave the way for other centralized storage projects in the French overseas departments with the broader goal of raising the minimum enewable energy penetration rate allowed by law, currently 30% in the overseas departments.


Quadran is in the process of commissioning its first wind power generation and storage facility in Guadeloupe and is developing photovoltaic solutions that include storage. The Enerstock project will pave the way for a France-based energy storage industry, with the medium-term goal of several megawatts’ capacity.


In the longer term, the project partners— manufacturers and grid operators in France—will leverage the storage solution and know-how developed under the project to off er new products and services to island grids worldwide. The regulatory environment will also help drive growth in the French overseas departments, with substantial financial incentives for electricity storage systems that were passed into law in 2014. This regulatory shift will spur the emergence of private storage equipment run by grid operators, starting in 2016.


The project mobilized around ten people amid strong revenue growth at Quadran. The results of the project will be leveraged by all Quadran business units addressing needs in isolated island communities. The electricity-storage projects resulting from Enerstock will also generate revenue for the islands where they are being built.


This project is co-certified by the poles of competitiveness S2E2 and Capenergies.



The French Single Interministerial Fund, ERDF, the Centre Regional Council, the Loiret General Council, and the Orléans Val de Loire Intermunicipal Authority.