Oh yeah! Wouldn't it be great if all homeowners were able to use the municipal water supply system to heat their homes in winter (with a heat exchanger) and cool their homes in the summer. Instead of putting solar arrays on your roof, why not just use the earth itself as a giant solar collector...or perhaps I should say 'absorber'. There are a few local governments in Canada (where I live) that don't meter any individual's water useage, simply charging everyone the same flat fee. And I've heard of some people taking advantage of this by using their tap water as the 'ground source' heat medium. They remove and concentrate the heat from the water (about 50 degrees farenheit year round) with an exchanger in winter and then send it back out through the sewer system - no wasted heat going up the chimney!