It's a demonstration project by Vienna's University of Natural Resources and Life Sciences (BOKU), to show how a green roof can be combined with solar panels while preserving the feel of a garden.

Thinking of installing solar panels on your roof? Here's a free tool that can help you save thousands and avoid scams first appeared on The Cool Down.

Opinions expressed by Forbes Contributors are their own. Daniela De Lorenzo is a Oslo-based reporter covering sustainability. Solar power is the cheapest source of clean energy currently on the ...

More information: Hou Jiang et al, Roofing Highways With Solar Panels Substantially Reduces Carbon Emissions and Traffic ...