Back in 2015 Google came up with the rather bright idea of using its mapping data to provide home owners with estimates for rooftop solar power yields. The service, dubbed Project Sunroof, has since grown to cover every US state and as of today, is available in Germany too.

Project Sunroof first kicked off in a handful of US cities and offered homeowners a way to assess the solar potential of their roofs. Fitting out a rooftop with solar panels isn't a cheap exercise, but Project Sunroof is Google's way of giving homeowners an idea of how much energy savings they can expect following that initial investment.

It takes aerial images from Google Maps and mixes them with 3D modeling of the roof, along with data on sun position, weather patterns and shade from nearby objects like trees and buildings. It then calculates how many hours of usable sunlight hits the roof, and estimates the possible energy production. Then, based on current solar pricing, it gives an estimate of the cost and savings if the user does go ahead.

To bring the service to Germany, the first time it has been available outside the US, Google partnered up with local energy provider E.ON and software company Tetraeder. It already covers around seven million German buildings including urban areas like Munich and Berlin, and by the end of this month the online tool will cover around 40 percent of German homes.

Source: Google