As more and more people will live in big cities, by placing Power Plants on the rooftops you don't have to fly it in from the other side of the world, you are able to grow it on the location itself.
De plus en plus de gens vont vivre dans des grandes villes. En installant des Power Plants sur les toits, nous ne devrons plus les exporter de l'autre bout du monde, nous pourrons les cultiver sur place.