Waste of space
Doesn't it make you angry when there's work to be done and people are being lazy?
There is over a kilowatt of energy hitting our rooftops and yet most of them insulate it out. While people are working all over the world to develop renewable energy production, our roofs are quite simply laying around in the sunshine and doing nothing. There's no excuse.
An editor of a top journal asked us for something that would grab attention, so we had a good long look at our roofs and we started to get angry about it. We shouted "lazy, lazy, lazy!" and "must work harder!" and "underachiever!"
It didn't help. The roof looked back at us and carried on sunbathing. In the end we just said "waste of space" and left it at that.