The business model behind a hybrid plant which uses solar PV, combined heat and power systems and battery storage at a commercial facility in Germany, could be adapted and scaled up elsewhere, according to General Electric (GE), one of the project’s partners.

The US company has collaborated on the project at a facility operated in Berlin by GE Power Conversion, a GE subsidiary, with solar technology provider Belectric, which contributed the 600kW rooftop solar array and Jenbacher, supplier of the plant’s 400kW combined heat and power (CHP) system.

The thinking behind the project has been to balance the different technologies – renewable and conventional with the system’s energy management controls. As well as powering the GE Power Conversion operations, the system can feed excess power back into the grid.

The final piece of the system’s main trinity of components is a 200kWh battery. At times when there is low energy consumption onsite but the hybrid system’s power output is high, the battery charges. The energy management controls then use it to discharge as necessary to meet demand anywhere else in the hybrid network. If the battery is completely full and the rest of the network does not need it, the storage can feed excess into the grid.

Additionally, Belectric’s executive chairman Bernhard Beck pointed out that the 600kW PV system is the world’s first to operate at 1,500 volts, meaning that less power electronics were necessary to wire in the system, reducing deployment costs. The array consists of 345 rows of 20 thin-film modules, which according to Beck still leaves room to expand it.

Developed by energy efficiency service provider Kofler Energies and BLS Energieplan, a GE-run planning office, a launch event was held for the system this week.

As well as solar and now energy storage, CHP plants are being considered an ever-more important and complementary part of distributed networks in Germany. Juggling the various energy demands of communities and businesses could be assisted by balancing the variable output of  A proposed amendment to the country’s Combine Heat and Power Generation Act (KWKG) could see Germany generating 25% of its power from CHP by 2025.

Meanwhile, the commercial rooftop segment is one that is spoken of with increasing potential for solar, especially in maturing markets such as Germany where falling feed-in tariffs (FiTs) have made large-scale ground mounted solar a less attractive proposition on a commercial basis than before. Similarly, the consensus from Japan when PV Tech visited PV Expo in Tokyo at the end of February seemed to be that commercial (and residential) rooftops will enjoy the lion's share of attention from the industry in the next few years as grid constraints and other factors have also moved that country's PV market on from large-scale.

In the US and UK, similar attempts are being made to boost the commercial rooftop segment, with SolarCity recently telling PV Tech's sister site PV Tech Storage that installing energy storage could give a strong boost to the cost-competitiveness of commercial PV in North America, where many commercial electricity users have hefty time of use charges and peak demand charges applied to their rates.