Saft, Conergy and Tenesol have launched SOLION, a Franco-German project to develop an integrated energy storage system able to be produced on an industrial scale for decentralized on-grid, residential PV systems. This project will introduce large lithium-ion batteries into PV systems on the largest scale yet tested in Europe.
|Example of residential PV system with energy storage. Click to enlarge.|
Saft is responsible for the design and the manufacturing of the storage system. The storage function (battery) design will be based on Li-ion battery modules which will be connected in series to obtain the energy and voltage required by the application.
Each module will include an electronic board for data acquisition (voltage, temperature, ..) and cell balancing in order to optimize the battery life time and to allow charge/discharge control, state of charge measurement, etc.
This electronic board will be connected to the system management which will pilot the battery. The interfaces will be developed both with Tenesol and Conergy. Saft will deliver the batteries both to Conergy and to Tenesol, who will produce the other components and will assembly the SOLION product (battery + inverter + system management).
The role of energy storage in an on-grid application—such as that of a residence with solar panels connected to the grid—is to store excess PV energy until it is needed. Effectively, energy storage will ‘time-shift’ PV energy produced during the day, peaking at noon, to make it available on demand. This will both maximize local consumption and enhance the efficiency of the PV system. Surplus energy can also be fed back into the grid, for which the owner of the PV system would be remunerated at a higher tariff.
Energy storage will also increase security of supply while making individual consumers less dependant on the grid and help to boost the development of energy self-sufficient houses and buildings and contribute to the continuous growth of PV as part of the global energy mix, according to the partners.
The main benefit of on-grid energy storage for utilities is that it will reduce the peak load on their grid while at the same time making PV a source of predictable, dispatchable power that they can call on when needed. Reduced grid losses ie the energy lost by transporting power from a centralized generator to the point of use will result in some energy savings. Savings due to reduced consumption in PV powered households are anticipated to be 10 to 20%.
Seventy-five systems will be deployed—25 in Germany and 50 in France. These trials will validate the performance of the system, its economic viability, the added value of energy storage in an on-grid PV system and the benefits for stakeholders.
Conergy AG is a leading solar enterprise in Europe and with over 70,000 solar systems installed also a global market leader in the field of solar system integration. Tenesol, created in 1983 is one of the first PV system manufacturer and integrator in France. The company, today a joint-venture (50/50) of EDF and Total, is addressing markets worldwide mainly in grid connected applications but also for off-grid in developing countries regarding professional applications and rural electrification.
SOLION has been recognized by the Eureka/Eurogia and Tenerrdis programs, and is supported by the French Ministry of Economy Finance and Employment (DGE) and the German Ministry of Environment (BMU). A German utility (E-ON), three German research institutes (ISEA, ISET & ZSW) and one French research institute (INES-CEA) are associated with this project.