Photovoltaics on Private Homes: GreenSketch AI Analysis Reveals 45 Billion Euros in Untapped Savings Potential on German Residential Rooftops

Munich - Germany's photovoltaic market is under growing pressure despite enormous economic potential. GreenSketch, the AI platform of Australian solar distributor OSW Group, has now published a new rooftop analysis providing comprehensive economic data for all German districts for the first time - revealing how large the gap between what is technically feasible and what has actually been installed on private homes still is.

To mark its market entry in Germany, GreenSketch is presenting the "German Rooftop Valuation Report", which according to the company is the first analysis to assess all 28 million private home rooftops in Germany individually using artificial intelligence. At the same time, the company is introducing its AI platform, which combines rooftop analysis, system design, lead generation and quote creation in a single system.

AI Assesses 28 Million Rooftops Individually: 45 Billion Euros in Annual Potential Untapped

At its market launch, GreenSketch presented the "German Rooftop Valuation Report" at an evening event ahead of Intersolar Europe 2026 at Villa Flora in Munich. According to the company, this is the first analysis to have assessed all 28 million private home rooftops in Germany individually using artificial intelligence. The key finding: an annual electricity cost savings potential of 45.43 billion euros remains largely untapped, as only 4.1 million German homeowners currently have a photovoltaic system installed.

The national average household could save around 1,620 euros per year - with an average investment of 12,167 euros and a payback period of approximately 8.44 years. The 20-year return is stated at 19,030 euros per household, with an internal rate of return (IRR) of 11.5 percent. All calculations are based on an optimised configuration of 10.34 kWp photovoltaics and 9.6 kWh battery storage; government subsidies are not included.

Methodologically, the report differs from simulation-based studies. According to the company, AI agent Emily analysed each rooftop individually on the basis of satellite imagery, AI-assisted 3D building reconstruction and geographic information systems. More than 87 percent of buildings were reconstructed as 3D models from 2D images in order to capture roof pitch, orientation and shading with address-level precision.

Bavaria Leads on Solar Returns - Berlin at the Bottom with Nearly 6,000 Euros Gap

The study reveals a pronounced regional performance divide. Bavaria leads in all five evaluated metrics: with an average annual saving of 1,696 euros, a payback period of 8 years and a 20-year return of 20,504 euros. Kempten (Allgäu) achieves the highest 20-year return of any German district at 21,719 euros.

Berlin ranks last: 1,388 euros in annual savings, a payback period of 10.10 years and a 20-year return of 14,555 euros - nearly 6,000 euros less than in Bavaria. Weak results are also found in the northern coastal regions and city-states. Nevertheless, even the weakest locations show positive returns - solar energy is worthwhile across Germany, according to the analysis.

Decline in Rooftop Installations Meets Regulatory Upheaval - GreenSketch Bets on Data Transparency

Installation figures for private rooftop systems fell by 21 percent in the first quarter of 2026 according to BSW Solar - even though Germany can only reach its target of 215 GW by 2030 with significantly greater momentum. The draft EEG 2027 also proposes abolishing the fixed feed-in tariff for new installations below 25 kW and capping grid feed-in from smaller systems at 50 percent of installed capacity - effectively making battery storage an economic prerequisite.

"Precisely because the framework conditions are changing, homeowners and installers need reliable data on what a roof is actually worth," says Christian Seidemann, Lead CSM DACH at GreenSketch. "For the first time, this report delivers address-level valuations for all of Germany and shows that rooftop systems pay off even without subsidies."

GreenSketch describes itself as a free end-to-end platform that combines rooftop analysis, system design, lead generation and quote creation in a single system. Homeowners can calculate their savings potential in 60 seconds and are then forwarded directly as a qualified lead to a suitable installer. The report was produced in collaboration with GoodWe and LONGi Solar and was independently reviewed by expert assessors according to the company. GreenSketch will be present at Intersolar Europe 2026 at stand A3520.

Source: IWR Online, 24 Jun 2026