Integrated storage solution for large-scale consumers

23 households, 145 kW PV power, one central electrical storage unit and several thermal storage units: In a flagship project in the German city of Weinsberg, KACO new energy shows that it is possible to provide complete energy coverage using photovoltaics.


Solar energy 24/7 – emergency power supply included

The motor for the power distribution is a bidirectional battery inverter by KACO new energy. This AC coupled unit charges and discharges the central lithium ion battery of 150 kWh capacity which is used as a buffer to store the solar power not used directly. Because of its enormous efficiency and very short reaction times, this battery inverter ensures uninterrupted electricity supply to the households, including stable, off-grid functioning for the whole estate in the event the public grid fails.

Serving the grid

In local networks, this inverter enables a higher level of photovoltaic penetration and affords the operators greater planning security. Consolidation of the load and generation profiles – peak shifting and peak shaving – keeps the cost of grid expansion to a minimum.

Thermal storage

Solar power which is not directed to electrical appliances is transferred to the thermal storage system: On the one hand it runs a 35 kWel heat pump which loads a 20,000 litre buffer storage unit. On top of that, 18 decentralised smaller water storage units are positioned on the individual buildings and heated directly to cover the daily warm water requirements.

Energy management

KACO new energy developed an energy management system which controls all of the electrical and thermal components for the residential complex. By perfectly matching the instant needs with long-term use patterns, this energy management system achieves an ideal balance between direct usage and both storage technologies. This means nothing less than maximum self-use.

Comprehensive monitoring

A complete measuring and monitoring system registers all of the electrical and thermal energy flows in the estate. The regular analysis of this data serves to continually optimise the energy management.

As a result, 97 percent of the electrical and about half of the heat requirements of the model estate are covered by decentralised generation and storage of electricity. Furthermore, our simulation shows that 100 percent coverage of the heat requirements is just a question of insulation.

Areas of application

All components and control instruments of the model development can be transferred to projects of almost any size: from large commercial and public buildings such as hotels, swimming pools and municipal facilities, right up to new housing estates and apartment buildings.

Which application are you thinking about? Discuss it with us. Email us at sales(at) or call +49 7132 3818-333.


Play video for a clear, concise description of the concept.

Further information





Fraunhofer ISE

Ministry for the Environment, Climate Protection and the Energy Sector Baden-Württemberg