LONGi supplies nearly 30,000 back contact modules for 18.7 MWp Söhnstetten solar park in Germany

An 18.7 MWp solar park in Söhnstetten, Baden-Württemberg, has been officially inaugurated following its grid connection earlier this year. The project uses 29,016 LONGi Hi-MO X10 bifacial solar modules based on the company's HPBC 2.0 back contact technology. Developed and constructed by ingenia projects GmbH & Co. KG, the 15-hectare installation is expected to generate approximately 21 million kilowatt-hours (kWh) of electricity annually, equivalent to the annual consumption of around 6,000 four-person households.

The Söhnstetten solar park was constructed during 2025 and 2026 and connected to the grid in the second quarter of 2026. Operated by Solarpark Söhnstetten GmbH & Co. KG, the installation is expected to avoid approximately 8,000 tonnes of CO₂ emissions annually.

“Söhnstetten is a good example of what modern solar technology can deliver on the ground. The project will generate a substantial amount of electricity for the region over the coming decades. As Germany expands its solar capacity, we need to pay closer attention to how much energy each installation can produce on the land available. This is where we see a clear advantage for our back contact technology, and it is an important part of our strategy for the German market,” said Gerald Müller, Vice General Manager DACH at LONGi Solar (DG).

LONGi Hi-MO X10 combines high efficiency with long-term reliability

The solar park is equipped with LONGi Hi-MO X10 bifacial modules, each rated at 645 Wp and offering a module efficiency of 23.9%. The modules use LONGi's second-generation Hybrid Passivated Back Contact (HPBC 2.0) technology, which places the electrical contacts on the rear of the solar cells. This design eliminates front-side metal grid shading and increases the active surface area available for sunlight absorption.

The integrated Shading Optimizer improves current management under partial shading, reducing power losses and limiting excessive hotspot temperatures. In comparative testing by the China Photovoltaic Product Quality Inspection Centre (CPVT), LONGi Hi-MO X10 modules demonstrated approximately 72% lower shading-related power loss than conventional TOPCon modules under the tested conditions.

Designed for long-term outdoor operation, the bifacial dual-glass modules are rated to withstand static snow loads of up to 5,400 Pa and wind suction loads of up to 2,400 Pa. LONGi provides a 15-year product warranty and a 30-year performance warranty, with defined minimum power output levels throughout the warranty period.

Project developed and constructed by ingenia projects

The Söhnstetten solar park was developed and constructed by ingenia projects GmbH & Co. KG as project developer and general contractor. The installation covers approximately 15 hectares of fenced land.