Enerparc and Naext: Battery Storage Developed for Ground-Mounted Solar Parks

The solar park investor, constructor, and operator Enerparc has developed a battery storage system for night-time power compensation for ground-mounted solar parks in collaboration with the Lower Saxony start-up Naext. According to both companies, the first four "Quadragons" installed at existing Enerparc facilities are running smoothly – thereby concluding the test phase of the storage cubes.

Avoiding Power Losses

The Quadragon addresses one of the central challenges of ground-mounted solar installations. These systems generate electricity when the sun shines – that is, during the day and in large quantities, especially during midday hours. This leads to a high load on the public power grid, so feed-in must sometimes be limited – unused solar power is lost. On the other hand, the installations' own components, such as transformers, require energy at night, which must be drawn from the grid. Therefore, the innovation team at Enerparc has been dealing with battery storage systems for several years now, as the need for them grows in parallel with the expansion of renewable energy systems.

Armin Scherl, Head of Innovations at Enerparc: “When we came into contact with Naext about two years ago, the idea quickly emerged to develop a battery storage system tailored to our needs in the planning and construction of our solar parks. After a year and a half of joint development time, we are very satisfied with the performance of the Quadragon.”

Henning Behn, Co-Founder of Naext GmbH, adds: “Together and with the expertise of the solar park developer, we succeeded in creating a scalable concept. It enables us to integrate our battery storage system into PV parks easily and quickly.”

Modular expandable battery container

The storage unit is the size of a ten-foot container and is easily modular expandable. A special feature: The Quadragon uses second-life car batteries with a total capacity of 600 kWh. The storage unit is connected on the AC side and can thus use the periphery of the solar park to compensate for consumption depending on the connection of the solar park up to medium-voltage or high-voltage level. Additionally, the Quadragon can use its own periphery to charge electric vehicles on the DC side with currently 120 kW and in the future with 240 kW. This double use of existing infrastructure creates an additional profit. Especially for rural areas where ground-mounted solar systems are primarily built, the offer of a fast charging point is interesting. Expensive fast charging stations often do not pay off in such areas.

"The storage of generated solar power is one of the biggest challenges of the energy transition. With the Naext Quadragon, we have solved a problem. Through it, we can cover the own energy needs of our solar parks at night. Likewise, the storage can provide reactive power, which we can feed into the grid for voltage support. The integrated fast charging point for electric cars is an additional side effect that allows us to pass on our own solar power at very favorable conditions in the context of the mobility transition," Scherl continued.