Most clean technology does not fail in the lab or on the balance sheet, but on the roof, the wall, the driveway or in the living room. Brilliantly conceived, expertly engineered – but pitifully ugly, uninspiring products. This is not vanity. It is a market failure hiding in plain sight. I have been watching it play out for nearly two decades, starting with Plumen. Back in 2007, the lighting industry had a real problem: how do you get people to switch from incandescent bulbs to energy-efficient ones?