Real estate investors key driver in rooftop PV systems

Wüest Partner's "Renewables Report Germany 2025" indicates that renewable sources supplied 61% of net electricity in Germany in H1 2025 – a 3.2% increase since 2023. 

Construction site - Wuest Partner

Rooftop photovoltaic (PV) systems are highlighted as a crucial driver of this transition, with real estate investors playing a vital role.
The report notes overall good progress in renewables expansion, though with variations. While wind power remains the largest source, it's falling short of targets. Solar energy, however, saw a record 17.3 gigawatt increase in 2024. The EEG's mandate for at least half of future PV installations to be rooftop systems makes them both a regulatory and economic necessity, significantly boosting their importance for real estate. 
The report identifies a multi-billion euro investment potential for real estate funds in rooftop PV. The upcoming Site Development Act (StoFöG) is expected to allow institutional investors to invest up to 15% of assets in project companies and complementary infrastructure like storage or charging stations. This alone represents over €15 bn for open-ended real estate funds.
However, challenges persist, including grid overload, slow expansion, policy uncertainty regarding feed-in tariffs, and more frequent periods of negative electricity prices. The share of building-integrated solar installations dropped below 50% in 2025. Without sufficient storage, revenue loss is a risk as electricity is often produced when the market value is low.
Despite these hurdles, the potential remains vast. GARBE estimates 360 million m2 of unused industrial and logistics rooftop space in Germany, with a technical potential of about 36 gigawatts. 
Thomas Lehmann MRICS, partner at Wüest Partner, commented: "Those who leave available roof space unused are foregoing predictable additional returns, CO₂ reduction, and increased property value. The framework conditions are good enough; we just need to get started. For investors with a real estate background, a thorough examination of the energy market before entering the market is becoming increasingly important."
Despite the obstacles, rooftop PV investments remain economically appealing. Maximising direct consumption is key to boosting cash flow. PV systems also serve as a strategic ESG tool, reducing carbon footprints and improving tenant loyalty.