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Sol Ion Europes Largest PV Energy Conversion And Storage Project Moves Into Field Trial Phase

• Close collaboration between industrial partners Saft, Voltwerk and Tenesol has resulted in the successful development of a prototype integrated energy kit suitable for production on an industrial scale

• EU-backed project is now moving into field trial phase with 75 Sol-ion energy kits being deployed in France and Germany from mid-2010 onwards

Saft, Voltwerk and Tenesol, industrial partners in the EU-backed Sol-ion project, have successfully completed the development phase by creating an integrated energy conversion and storage kit, capable of production on an industrial scale, for decentralized on-grid, residential solar photovoltaic (PV) systems. The project, which commenced in August 2008, is now moving into its test and evaluation phase. This involves the deployment of 75 Sol-ion energy kits for field trials across France and Germany.

The Sol-ion trials will see Li-ion (lithium-ion) batteries used in PV systems on the largest scale ever tested in Europe. 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.

Sol-ion kit

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.


Saft’s technology partners in the Sol-ion project are leading PV systems providers and integrators: Germany’s Voltwerk has installed over 70,000 PV systems; France’s Tenesol supplies integrated PV systems and also manufactures solar panels. E-ON, the German utility, three German research institutes (ISEA, Fraunhofer IWES and ZSW) and INES-CEA, the French research institute, are also associated with this project.

Sol-ion has been recognized by the EU/Eureka/Eurogia programme and has the support of the French Ministry of Economy, Finance and Employment and the German Ministry of Environment.

About Saft

Saft (Euronext: Saft) is a world specialist in the design and manufacture of high-tech batteries for industry. Saft batteries are used in high performance applications, such as industrial infrastructure and processes, transportation, space and defence. Saft is the world’s leading manufacturer of nickel batteries for industrial applications and of primary lithium batteries for a wide range of end markets. The group is also the European leader for specialised advanced technologies for the defence and space industries and world leader in lithium-ion satellite batteries. Saft is also delivering its lithium-ion technology to the emerging applications of clean vehicles and renewable energy storage. With approximately 4,000 employees worldwide, Saft is present in 18 countries. Its 15 manufacturing sites and extensive sales network enable the group to serve its customers worldwide. Saft is listed in the SBF 120 index on the Paris Stock Market.
For more information, visit Saft at www.saftbatteries.com http://www.saftbatteries.com

About Voltwerk electronics GmbH

Voltwerk electronics GmbH is an internationally successful manufacturer of string and central inverters, tracking systems and facility monitoring systems. All its products are developed and manufactured in Germany. Voltwerk‘s award-winning products have been installed worldwide in systems with a total of more than 500 MW of generating capacity. Voltwerk is a provider of innovative solutions and pioneering methods for highly efficient photovoltaic systems. Voltwerk’s success is based on precise knowledge of the markets and intensive collaboration with customers and engineering teams across the world. Voltwerk is represented in Bad Vilbel and Hamburg and has sales and service support in all the major European markets. Voltwerk electronics GmbH currently has nearly 100 employees. For more information visit Voltwerk at www.voltwerk.com.

About Tenesol

A rapidly expanding global player in the field of solar energy (with a turnover of €249 million in 2009, +29%), Tenesol works on behalf of businesses, local authorities and private individuals. For more than 26 years, Tenesol has been engineering, designing, manufacturing, installing and managing solar energy systems including production and consumption of supplied systems (Off-grid sites, general grid supply via direct connection, solar water heating) for its customers around the globe. A benchmark player in its sector, Tenesol currently has a staff of over 1,000 employees across 20 subsidiaries including 2 production facilities. For more information visit Tenesol at www.tenesol.com.