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AC-Batteries - Prototyping and testing of a flexible energy storage for stand-alone pv systems


Project summary
The objectives of the project are to design, build and test a novel battery concept for the storage of electrical energy in stand-alone PV systems: the AC battery. The proposed AC battery unit is composed of a conventional DC lead acid battery and a bi-directional inverter for charging and discharging at 230 VAC. The unit will include additional control and communication functions for enhanced battery management.
Modular structuring of a stand-alone PV system (SAPV) on the basis of ACbatteries and AC-modules will have a number of significant advantages for the system design procedure, the system installation as well as the maintenance of the system. The most notable advantages of the AC-battery concept will be:
- straightforward installation;
- highly flexible expandability;
- enhancement in battery lifetime;
- improved reliability of the system.
Furthermore, because of the 230 V interface the AC battery concept can have a strong impact on user acceptation for electrification by stand-alone PV. The balance of system costs for an AC battery system have to be competitive with those for a conventional stand-alone PV systems of similar performance. Additionally, accordingly to the improvement in battery life the AC battery concept will have a positive effect on the environmental balance of SAPV
The research will start with the development of a programme of requirements and design specifications by the participants, on basis of their respective competency and know-how. This includes identification of the relevant productmarket combinations, consumer demands, as well as technical requirements. These design specifications will be the input for the technical development of a prototype. In parallel with the development of the first prototypes test procedures for the evaluation of these units will be designed. 2 prototypes will be manufactured, tested at the partners facilities and optimised for the field test. After successful testing, about 50 prototypes will be manufactured for testing in 5 pilot systems. The pilot systems will be closely monitored for about one and a half year. Monitoring results and data-analysis as well as user response will be evaluated. Conclusions will be drawn with respect to the overall performance of the AC battery concept. Specific suggestions for improvements and considerations for future industrial design will be made.
The result of the project will be a strong basis for a new industrial product. It is anticipated that the results will point towards further improvements and optimisation of the AC battery. After the end of the project a foreseeable period of one year of additional development and industrial design will be needed to create a fully reliable, user-friendly and market-ready product.

Funding Scheme

CSC - Cost-sharing contracts


Kanaalweg 16 G

Participants (3)

Accumulatorenfabrik Sonnenschein GmbH
63654 Büdingen
Intervolt BV
1101 AJ Amsterdam
Trama TecnoAmbiental SL
46,Carrer Ripolles
08026 Barcelona