Can someone turn down the lake? I'm freezing!

Toronto has come up with an ingenious alternative to conventional air-conditioning for their office buildings and homes downtown. Using their Enwave system, intake pipes stretch out 5km into Lake Ontario to a depth of 83 meters. At this depth, the water is near-freezing (4° C) year-round. It is then piped to the filtration plant where a heat exchanger chills the water in the loop that supplies the air-conditioning for the downtown buildings. The lakewater then continues its journey into the city's drinking water system.

They note that the cooling system reduces energy usage, freeing up megawatts from the Ontario's electrical grid, minimizes ozone-depleting refrigerants and reduces the amount of carbon dioxide entering the air. The company claims they have the capacity to air-condition to 100 office buildings or 8,000 homes, equivalent to 32 million square feet of building space.

It sounds a little complicated as I describe it, but it is much more clear after checking out the explanation at Enwave's site.
(via Slashdot)