MOVE ON Energy GmbH, based in Lobstädt, Germany, specializes in the planning and realization of solar power plants and is currently involved in the development of Europe's largest solar park, the Witznitz Solar Park near Leipzig, Germany. The project, which started in 2022, now boasts a fully operational capacity of 650 megawatts. For this significant endeavor, MOVE ON Energy selected Delta as its inverter supplier.
From open-cast lignite mine to solar park
The Witznitz Solar Park was constructed on a former open-cast lignite mine with limited agricultural use, making it one of Germany’s largest conversion projects in the energy transition. This project exemplifies the successful transformation of a coal mining region into a hub for sustainable energy generation. It- is the first solar park of this size to be connected directly to the 380 kV grid. The ground-breaking ceremony for this solar park took place in June 2022. According to MOVE ON Energy GmbH, up to 500 workers were simultaneously involved in the construction work at peak times. The plant spans 500 hectares – an area equivalent to 700 football fields – across the municipalities of Neukieritzsch, the town of Böhlen and the town of Rötha.
A project of gigantic proportions
The total area of the Witznitz Solar Park spans 500 hectares, comparable in size to Hamburg Airport. This immense scale is matched by impressive technical specifications: approximately 1.1 million solar modules and around 3,500 Delta PV inverters (M125HV model) collectively generate 650 megawatts of DC green electricity. This output is sufficient to power industrial operations and a substantial number of homes. Specifically, the solar energy produced can supply the annual electricity needs of 200,000 households of four, highlighting the plant's substantial contribution to renewable energy. Moreover, the project is projected to reduce carbon emissions by over 250,000 tons annually, significantly decreasing its environmental footprint. The solar park's 1.1 million modules were delivered on nearly 30,000 pallets. According to MOVE ON Energy GmbH, the park generates approximately 35 percent of the output of the nearby Lippendorf power plant. The installation includes around 7,500 module tables, which, if laid end-to-end, would span 440 kilometers—equivalent to the entire length of the A5 motorway. Additionally, the DC cables used for connecting the modules extend approximately 550 kilometers, and 207 transformer stations have been installed to support the infrastructure.
A strong partner for a successful project
MOVE ON opted for Delta to cover the needs of around 3,500 inverters at the site. “We chose Delta for this major project because with Delta, we were able to obtain the system certificate for the extra-high voltage and in parallel for the high voltage,” explains Wolfgang Pielmaier, Technical Director and Co-Partner of MOVE ON Energy. “But of course also because of the technical features of the individual inverters, so that we were able to create a perfectly coordinated situation with the inverters.
“The M125HV PV inverter is ideally suited for this project,” says Hansu Chae, PV Sales Manager at Delta Electronics, EMEA. “They are designed for the 1500 volt DC and 600 volt AC system and come with an MPP tracker for up to 20 DC strings (module strings), which enables us to design very long tables with these inverters,” says Chae. The inverters are also certified in accordance with VDE-AR-N 4120/4130 for extra-high voltage, which is important because the energy park feeds into the highest voltage level - 380 kilovolts.
The robust housing of the inverters comes with an IP65 protection rating, making it suitable for harsh environments. The intelligent cooling system with replaceable fan modules enables operation at temperatures of up to +60 degrees. The M125HV inverters stand out in particular due to their high peak efficiency of 99.1 percent. This is a particular highlight for comparable projects, as Andreas Hoischen, Senior Director and Head of Photovoltaic Inverter Solutions Delta EMEA, reports: “These inverters do not require any maintenance work as they are actively ventilated. This means that the inverters can deliver full power even at high temperatures and do not have to undergo a so-called de-rating. “
Key features of the system include string monitoring, arc fault detection, reverse polarity protection, and anti-PID functionality. In addition, it is also equipped with replaceable Type 2 AC and DC surge protection devices. For straightforward commissioning and parameter configuration, the inverter integrates a Bluetooth® interface, allowing local management via the DeltaSolar App. Additionally, the inverter offers RS485 ports, digital inputs, dry contacts, and a 12 VDC power supply for easy remote maintenance.
A solar park of superlatives
With a team of over 10,000 engineers in development and more than 25 years of experience in the photovoltaic industry, Delta was well-equipped to deliver the services needed for the project. This included appointing a dedicated project manager for the plant. “Projects of this size are something extraordinary for Delta and we are very proud to be able to be involved in this project as a supplier", explains Andreas Hoischen.
The solar plant is engineered to produce a peak of 650 GWh of electricity annually. The energy collected in the module field is gathered by 207 PV transformer stations, with each station connecting twelve to eighteen inverters. The generated electricity is then transmitted to an overhead line at the site through a purpose-built transformer station, which includes two 110 kilovolt transformers and two 380 kilovolt transformers. The Witznitz Solar Park as a whole produces a total of 0.6 TWhof electricity per year. This could be enough to supply private households in Leipzig. However, it should be emphasized that the electricity from the plant was not used for private households, but instead sold by an insurance company as an investor to one of the world's largest oil and gas companies. This company wants to use the solar power to profitably transition to a net-zero emissions energy business by 2050.
A power plant combined with a green oasis
The solar park also brings ecological benefits. Various nesting boxes have been installed for birds and bats, and rock piles, deadwood, and small ponds have been introduced in open areas. Beyond electricity production, efforts to enhance local biodiversity include cultivating nearly 23 kilometers of field hedges, serving as privacy screens and breeding grounds, along with creating flowering meadows. According to MOVE ON Energy, the perimeter fences around the areas with PV modules are designed to allow small animals, such as hedgehogs, hares, and foxes, to pass through. Additionally, open corridors between the fenced areas provide pathways for deer and other large animals, which are bordered by hedges to facilitate safe passage.
“We at Delta are proud to have worked with MOVE ON Energy on this project and to have supplied a key technology for further progress in the energy transition with our power electronics. Every day, more than 500 of our employees in Germany alone contribute to the development of intelligent, environmentally friendly energy solutions,” concludes Andreas Hoischen.