When Madison set out in 2004 to become what Mayor David Cieslewicz called a “green capital city,” not one municipal property had yet taken advantage of solar hot water. Four years later, each of Madison’s 11 firehouses is equipped with a solar hot water system, serving anywhere from 45 percent to 60 percent of the buildings’ collective hot water loads and offsetting 205 tons of carbon dioxide (CO2) emissions each year. It’s fair to say that no other city in the country has been as aggressive or as successful as Madison in incorporating solar water heating into its municipal buildings.