A recent small housing development near here has built in solar panels on all the roofs. However, they are upmarket properties, not run of the mill 'affordable' properties, so I think we are a long way away from that yet. My son has had solar panels for some years, having bought them when the feed in tariffs were at their highest. He has been very pleased with them. However, this year he has had a problem with the bit of kit that converts the current from DC to AC, and is still waiting for a new one to be supplied and fitted. He has lost the advantage of practically all the summer weather - effectively several hundred pounds worth. So, they are not without their potential problems.