Why Cool Roofs?


SECRETARY OF ENERGY STEVEN CHU: The reason we wanted the Department of Energy to take the lead in cool roofs is to demonstrate that this really saves money. If you have a roof and it’s black, it’s absorbing energy from the sun and it’s getting hot. And it increases air conditioning bills; it does a lot of things. If you have a white or a reflective roof that scatters back the visible radiation, of course it reduces your energy consumption, but one of the amazing things about it is it also reflects that energy back into space. There is very little greenhouse gas effect for visible light. It’s – the heat light is being trapped by the carbon dioxide and the water vapor and other gases. And so it helps keep the Earth cool in that way, as well. It’s not only your home that’s being cooled; the Earth is being kept cool.

The department is installing cool roofs whenever financially possible, which means whenever there’s a new roof, whenever there’s a re-roof, let’s do some analysis: By putting a cool roof on there, are you going to save money over the lifetime of the roof? And if you are, put in a cool roof. I’m utterly convinced in most of the cases you will actually save money. Don’t re-roof with a blacktop roof just because that’s a roof you’re used to. As we transition to cleaner sources of energy, the cleanest source of energy is the energy you don’t use and you don’t have to generate, but in a way that doesn’t impact your lifestyle..