Fears that, when it came to installing rooftop PV, the networks would be strained past endurance, are misplaced, Phil Jones, chief executive of Northern Powergrid, told the Future of Utilities conference. The company had assumed it would only be able to accept a limited number of rooftop systems but that was not the case. Research on panels in practice showed the network could handle a whopping 137% of rooftops – all the houses and lots of garages too. Why was the assumption so far out?