Sol-ion, Europe’s largest PV energy conversion and storage project, moves into field trial phase

The trials will be used to assess the performance of the technology, its economic viability, the added value of energy storage in an on-grid system and the benefits to stakeholders. ‘The key to the success of the Sol-ion project is the way that all the individual partners, both from industry and from the research institutes, have come together in close collaboration to function as a seamless team. So rather than each partner providing a separate element – batteries, energy conversion and system management – and then bringing them together, we have focused right from the very start on the delivery of a comprehensive, fully-integrated, optimized solution’ says Michael Lippert, Marketing Manager of Saft’s Energy Storage activities. ‘We are very excited to be moving into the field trial phase as this will provide invaluable practical experience and feedback that will help refine our approach as we move a step closer towards making PV energy storage kits commercially available.’

Currently, the majority of grid-connected PV systems do not include energy storage and the electricity produced is fed into the grid directly, in real time. The advantage of the Sol-ion energy conversion and storage concept is that solar energy can be ‘time-shifted’ to periods of peak demand or when there is no sun, allowing self-consumption or grid support. The field trials will demonstrate the benefits to the environment and to stakeholders of storing PV energy. One key benefit will be to reduce the impact of intermittent injection to power grids, thus allowing a higher penetration of PV energy in the electricity mix.

The Sol-ion kit has been developed to accommodate PV energy production of 5 kWp (peak) with a battery rated from 5 to 15 kWh and a nominal voltage of 170 V to 350 V. Li-ion is the only technology that meets the project’s need for 20-year battery life in demanding environmental conditions. The energy conversion and system management systems are designed to handle four system functions: multidirectional energy flows; self-consumption; grid support; back-up. They are also intended to handle requirements for demand side management such as control over storage and loads using smart metering, and integration within future smart grids that will need to handle demand response and dynamic pricing. The Sol-ion battery is based on Saft’s high energy Li-ion modules, with a nominal voltage of 48 V and 2.2 kWh capacity. These compact, maintenance-free modules feature an advanced and robust industrial design, and they can easily be connected in series or parallel to create the desired voltage and capacity for each installation. Saft’s Li-ion technology has already proven an impressive 97% energy efficiency in a recent 2 years field demonstration in residential PV systems in Guadeloupe.