The research is in – green roofs and rooftop solar work even better together.
A solar array combined with a green roof produces more electricity and can filter a significant amount stormwater, says a recent Sydney-based study attracting global media attention.
We hosted a webinar with the study’s research team and participants University of Technology Sydney, Lendlease and Junglefy.
Hear these passionate researchers talk about the project and how roofs like these can help make our cities more resilient in a changing climate.
Solar panels work best on cooler green rooftops
The study found:
- Surface temperatures were up to 20°C lower on the green roof in summer.
- Temperatures inside the building with the green roof were up to 7°C cooler in summer and 5°C cooler in autumn.
- Solar panels work best when temperatures are up to 25°C – not higher
- Over the 8-month study, solar panels on the green roof produced 3.6% more electricity than those on the neighbouring rooftop. This provides an extra $2,595 worth of renewable electricity.
- The green roof reduced stormwater runoff by more than 600 litres a second, reducing the impacts of flooding during more intense storm events.
A few creepy, crawly and feathered surprises
The study also found some unexpected creatures thrived on the roof, including native blue banded bees and lychee metallic shield bugs. Insect life increased 7-fold and bird life increased 4-fold.
This project was a partnership between Lendlease, UTS and Junglefy. The City of Sydney funded the research portion of the project through an innovation grant.
Published 25 October 2021, updated 13 October 2023
