green roofs and solar panels

As green roofs and solar panels may often compete for the same rooftop space, there is also some
debate as to which technology best solves the city’s energy problems. Theoretical knowledge of photovoltaic
(PV) semi-conductors suggests that these two technologies actually work best in tandem.19 It is
well-known that PVs work more efficiently when the ambient temperatures are lowered to below 25°C

which in many cases can only be done cost-effectively through greenery. Similarly, PVs provide some shade which expands the available plant palette and ameliorates the growing and soil conditions.
Research into this symbiotic relationship is early and ongoing. Apart from combined weight constraints,there is little preventing solar panels being installed on frames above a green roof. In fact, combing the routine inspections for both technologies may also provide a saving than if only one of the technologies were used.