For years engineers have been working on a viable energy storage system for solar panels. Such a technology will enable solar power to be time shifted, allowing grid connected systems to self-consume the energy they produce as well as feeding some power into the electricity grid.
PV energy storage will make solar technology a more efficient and cost-effective renewable energy resource, says Benoit Rolland, managing director of Tenesol. System operators will benefit from a self-sufficient power source, rather than buying it back from the electricity supplier they feed into. It will also make the solar industry more stable and less reliant on government incentives.
The start of something new
In 2008, Tenesol, together with several leading associations from France and Germany, set out to create a new technology in energy storage for grid connected PV systems. The solution provides energy conversion and system management. Its functions include multidirectional energy flows, self-consumption, grid support and back-up.
Following one of the largest field tests ever undertaken in Europe, the 9 million project has now delivered a working system that can be mass produced.
The solution can be retrofitted to residential and small commercial systems. It can accommodate PV energy production of up to 5 kWp for more than 20 years. The system uses lithium-ion batteries rated from eight to 13 kWh with a nominal voltage of 190 V to 290 V. The batteries are compact and highly energy efficient, and in a recent two year field test reached an impressive 97 percent efficiency.
Cost saving
The new storage system could save operators up to 9.5 cents for each kWh of solar energy they consume instead of feeding into the grid.
When you look at Germany, specifically, electricity is very expensive, explains Engin Yaman, general manager of Tenesol Germany. It is our job to educate customers about self-consumption. Solar energy is not only an environmentally responsible choice but also a financially attractive one.
Less FIT reliant
Shifting the solar industrys focus from government incentives and feed-in-tariffs will help bring the industrys many benefits back into the spotlight Self-consumption will improve the stability and longevity of the global solar market.
The first generation of solar systems was grid connected, explains Yaman. We believe the second generation will be all about decentralised systems that allow for self-consumption. The industry as a whole has come to the conclusion that the best way to move ahead with solar is to have companies, industries and indeed households consume the energy they produce themselves.
The energy storage project has been recognized by the Eureka/Eurogia and Tenerrdis EU programs, and is supported by French and German government associations, as well as research institutes from both countries.
