In Vancouver, today's bathwater is tomorrow's central heating

A local energy centre heats homes using warm water from the city's sewers. But not in a gross way.

It's crazy when you think about it. From showering in the morning to draining the pasta for dinner, we each put gallons of hot water down the drain every day.

Mix it all up, and it's enough to keep our sewers flowing at a balmy average of 15C. That's a lot of energy babies being thrown out with our bathwater.

I've always thought there should be a way to re-use that heat, but I suspect the demand for lukewarm sewage-filled radiators is fairly modest. Luckily, there's another way.

Cities in Norway, Japan and even China are pioneering special treatment plants that use heat exchangers to suck precious warmth out of the icky drain water and sending it back to our taps and radiators, without any gross touching or mixing together. Plumb it in the right way, and one of these plants can provide about 70% of a community's heating needs.

So, less waste, lower emissions, and no stray bits of spaghetti in the bidet. Good.

But not quite good enough for the Canadian city of Vancouver, who've taken the opportunity to make sewage processing beautiful and informative, as well as super-efficient. Their heat recovery plant, hooked up to the Olympic Village area is a piece of public art in its own right, with tasteful accent lighting that changes from blue to red as demand goes up and down.

You stay classy, Canada.

Photo: David Dodge, Green Energy Futures