Corsica, the birthplace of Napoleon Bonaparte, is an island off the coast of France that is no stranger to renewable energy. An island does not have many choices for a viable source of energy like underwater power cables from the mainland or its own power generating plant, but some sort of fuel will need to be delivered by boat to power it. Renewable energy makes sense.
In an earlier program, in 2012, a hydrogen-based storage solution made of an electrolyzer, hydrogen and oxygen reserves, and a fuel cell was implemented in their 560 kWc photovoltaic power plant.
This hydrogen storage system functions by a state-of-charge control method. The control system verifies the state of charge (SOC) of the batteries and then sends commands to the electrolyzer or the fuel cell by way of DC/DC converters. When the state of charge of the batteries is high, the system activates the electrolyzer by sending a command to the buck converter (to lower the energy level). The excess energy is converted into stored hydrogen.
When the state of charge of the batteries is low the control system activates the fuel cell via the boost converter (which increases the energy level). The energy of the stocked hydrogen thereby converted appears as electrical energy which is sent to the DC bus to supply loads or to recharge the batteries.
Lithium Ion storage
Hydrogen storage is a nice potential idea, but my opinion is that there is much more experimentation and testing that needs to be done to mature a hydrogen system for widely accepted storage use. I believe that the primary storage energy system technology available today is the well matured Lithium Ion cell.
The Langa group is financing and building the new solar power plants that will have a nominal solar power of 1 MWp and a storage capacity of 1 MWh, each plant will produce more than 1,300 MWh per year, in compliance with the CRE specifications.
Schneider Electric and Saft partnered to meet Langa’s requirements on those two projects. The consortium proposed a solution including the design, supply and installation of the equipment, management system, and the maintenance services.
The combination of the photovoltaic power generation plus a viable storage system optimizes the integration of variable solar energy into the island electric grid. Energy produced during day times when sun supplies most of its energy will be stored in batteries, and redistributed in the evening, during peak times and after sunset. The two photovoltaic plants will generate enough energy to meet the electricity needs of more than 400 Corsican homes per year.
A French consortium for a global solution
Schneider Electric will implement its solutions dedicated to storage and solar energy: PV Box for solar power conversion, ES Box for battery power conversion, Energy Management System (EMS) for global equipment management and control of Saft batteries, project engineering and services to guarantee the system performance.
They are also in charge of the interconnection between the various components of the plants, and with the electric distribution network.
For each project, Saft will deploy its energy storage solution Intensium Max+ 20E. This integrated solution is fully developed and manufactured by Saft, and composed of a lithium-ion (Li-ion) battery of around 1 MWh in a 20 foot container.
The container also includes the thermal and safety management systems, as well as the operational battery management through a BMS (Battery Management System), the interface with the Schneider Electric control system.
The two installations will be grid connected by the end of the year.
Energy storage systems are absolutely critical for continued growth of renewable energies: they will allow the integration of energy production into the distribution grid in an optimized and consistent manner.
1 Modelling and Simulation of a Hydrogen Based, Photovoltaic/Wind Energy System , M. Doumbia, K. Agbossou, E. Granger