With the commissioning of the new substation, ENERPARC, WT Energiesysteme, and Siemens—in collaboration with the municipality of Ahausen—are laying the groundwork for reliably feeding electricity generated at the neighboring solar park into the public grid in the future. With a capacity of 64 megawatts peak, the solar park will supply clean electricity to approximately 18,000 four-person households. In addition, ENERPARC is planning a battery storage system that will be able to temporarily store the solar power generated in the future.
ENERPARC, WT Energiesysteme, and Siemens jointly built the substation. As the general contractor, WT Energiesysteme was responsible for the planning, construction, and commissioning of the facility. ENERPARC acted as the client’s representative, financed the project, and will operate both the substation and the solar park as part of its own portfolio over the long term.
A technological highlight of the substation is the modern switchgear designed for voltages up to 40 kilovolts. It uses “Clean Air” as an insulating medium—a climate-friendly solution based on natural air components. In addition to its high operational safety, the facility is characterized by its reliability and fire safety. Integrated sensors continuously provide data on the facility’s status and enable real-time digital monitoring of the substation via the Electrification X IoT platform.
The Ahausen project thus not only creates the conditions for connecting a 64-MWp solar park to the grid. At the same time, the project demonstrates how innovative switchgear technology, modern grid infrastructure, and renewable energy generation can be successfully integrated.
The municipality of Ahausen supported the project from the very beginning. The grid operator Avacon also played a constructive role in the planning, permitting, and connection processes, ensuring swift implementation.
Stefan Müller, COO of ENERPARC AG: “The energy transition requires not only renewable generation capacity but also the necessary infrastructure. With the substation in Ahausen, we are creating the conditions to safely integrate large amounts of clean electricity into the grid. At the same time, the project demonstrates how the energy transition can be successfully implemented at the local level when municipalities, grid operators, and industry work together toward a common goal.”
In addition to solar parks, ENERPARC develops, builds, and operates other infrastructure facilities for the energy transition. These include substations and large-scale battery storage systems. With the Ahausen site, the company is adding its 37th substation to its German portfolio.
Dietmar Tietz, Managing Director of WT Energiesysteme GmbH: “As the first customer worldwide, we are using the new 8DAB 40 blue GIS in a substation for renewable energy. We don’t wait until innovations have become the market standard before putting them to use. We want to test new technologies early on under real-world conditions and apply the experience gained directly to future projects. Our customers benefit from this through a technological edge and the assurance of relying on solutions that have been proven in practice.”
Christoph Menger, Head of the Electrification & Automation Business Unit Germany, Siemens AG: “The demands on modern energy infrastructures are growing rapidly. The grid is the decisive factor for the success of the energy transition. With the 8DAB 40 - blue GIS, which is also in use here in Ahausen, we not only offer an F-gas-free switchgear system but also combine sustainability, security of supply, and digital transparency. In doing so, we create real added value for our customers worldwide while also making an important contribution to a climate-friendly, resilient, and digital energy supply.”
Christian Meyer, Minister of Energy and Climate Protection for Lower Saxony: “Renewable energies, grids, and storage systems contribute significantly to local economic growth and lower electricity prices in Lower Saxony—the No. 1 state for the energy transition—as well as to phasing out expensive imports of fossil fuels.”
Key project data:
Solar park with a capacity of 64 MWp covering an area of approximately 59 hectares
Green electricity for approximately 18,000 households
New substation serving as the grid connection point for the solar park
World’s first integration of the Siemens 8DAB 40 blue GIS in a substation for renewable energy
F-gas-free technology based on Clean Air
Planned expansion to include a battery storage system with a capacity of up to 50 MW
About ENERPARC
ENERPARC AG, headquartered in Hamburg, is one of the largest developers, builders, and operators of large-scale photovoltaic plants in Europe. The company covers the entire solar value chain—from project development through financing and construction to long-term operation and electricity sales. Since its founding in 2008, ENERPARC has installed more than 1,000 solar parks worldwide with a capacity of approximately 6.6 gigawatts-peak. Today, the group’s own installed portfolio comprises 760 solar parks with a capacity of over 5 gigawatts-peak, 32 large-scale battery storage systems with a capacity of approximately 500 megawatt-hours, and 37 substations.
About WT Energiesysteme
WT Energiesysteme GmbH is an established builder of substations in Germany. The company carries out complex projects in the high- and extra-high-voltage sectors, managing them from planning through implementation to commissioning and service. With extensive experience gained from over 250 projects, WT Energiesysteme applies its proven expertise specifically to the extra-high-voltage level, thereby actively driving the further development of power grids and the integration of renewable energy.
About Siemens
Siemens AG (Berlin and Munich) is a leading technology company focused on the fields of industry, infrastructure, mobility, and healthcare. The company’s mission is to develop technology that improves everyday life for everyone. By connecting the physical and digital worlds, it enables customers to accelerate their digital and sustainable transformation. This makes factories more efficient, cities more livable, and transportation more sustainable. As a leader in industrial artificial intelligence, Siemens leverages its extensive expertise to apply AI—including generative AI—to real-world applications and develops AI solutions for customers across all industries that deliver real added value. Siemens is the majority owner of the publicly traded company Siemens Healthineers, a global leader in medical technology that is pioneering advancements in healthcare. For everyone. Everywhere. Sustainably. In fiscal year 2025, which ended on September 30, 2025, the Siemens Group generated revenue of 78.9 billion euros and net income of 10.4 billion euros. As of September 30, 2025, the company employed approximately 318,000 people worldwide on a continuing operations basis.
In the photo, from left to right: Dietmar Tietz, Minister Christian Meyer, Stefan Müller, Christoph Menger; Copyright: ENERPARC AG