It will get dirty, and the efficiency will likely drop. But white roofing material can help to lower temps in heat islands: https://www.google.com/amp/s/www.b

It will get dirty, and the efficiency will likely drop. But white roofing material can help to lower temps in heat islands: https://www.google.com/amp/s/www.businessinsider.com/new-york-city-painted-6-million-square-feet-of-rooftop-white-2018-8%3Famp https://www.google.com/amp/s/www.businessinsider.com/new-yor...