On a crisp January morning, the slanting winter sunlight falls across a row of Victorian terraces in north London. At first glance, these brick-built homes look as they have for decades—weathered, modest, quintessentially British. But peer upward, and you’ll notice something distinctly futuristic. Where once there were only sooty chimney pots and mossy slates, sleek photovoltaic (PV) panels now glimmer.