Back-contact technology emerges as preferred choice in offshore PV as LONGi secures 400 MW contract with Shanghai Electric Power

LONGi has signed a contract to supply 400 MW of photovoltaic modules for an offshore wind–solar hybrid project operated by Shanghai Electric Power Co., Ltd., marking a major step in the deployment of back-contact (BC) solar technology in marine environments. The supply commenced ahead of schedule in October 2025.  

BC technology becomes standard in offshore PV

The contract confirms that BC modules are the chosen technology for Shanghai’s first 1 GW (AC capacity) co-located offshore wind and solar project. Module selection criteria emphasised high power generation per square metre, robustness in harsh sea conditions and cost reductions in support structures and foundations. By adopting BC modules alone for the PV component, the project signals a shift in the offshore sector from traditional module technologies to higher‐density, marine‐optimised solutions.  

Performance advantages of BC modules in marine settings

LONGi’s BC modules deliver around 40 W more power compared with equivalent sized TOPCon modules, according to the company’s data. This differential translates into lower area usage and reduced balance-of-system costs, especially relevant where sea‐surface area is at a premium and installation windows are constrained. Offshore test-beds in Yantai and Sanmen validated the performance of BC modules under salt‐spray, humidity and elevated temperature conditions, providing empirical reference for module selection in marine PV applications.  

Implications for the solar market and supply chain

Offshore PV projects bring heightened technical and commercial demands: limited land or sea area, harsher operating environments, tighter structural and support-foundation constraints. The technology choice thus becomes strategic rather than simply cost-per-watt driven. By securing the contract and positioning BC modules as the preferred solution in this scenario, LONGi strengthens its value proposition for developers and EPCs in offshore and other high-complexity solar markets. The move underscores the evolving module selection criteria in the solar industry, where environment-specific technology optimisation and lifecycle cost considerations are increasingly decisive.

Europe begins scaling offshore PV through pilot projects and regulatory recognition

In Europe the development of offshore solar photovoltaics is still at an early stage but shows measurable progress. The European Commission’s 2025 Recommendation on offshore renewable energy encourages Member States to design support schemes that include innovative technologies such as offshore floating solar. The EU-funded EU-SCORES project is currently validating offshore solar through a 2.6 MW grid-connected system off the Belgian coast, demonstrating technical feasibility in North Sea conditions. Industry analyses also note rapid growth in floating-PV activity across Europe, with more than 100 MW of new projects announced in countries including Italy and the Netherlands in 2024. Together these developments suggest that offshore PV is becoming an additional deployment pathway for the European solar sector, particularly in regions with limited land availability and where synergies with offshore wind and existing marine infrastructure can be leveraged.

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