Power/energy: Solar energy: Four sites demonstrate potential: An office building in Florida, a warehouse in New Hampshire, a gymnasium in Iowa, and a laundry in California exploit sun power

For all the discussion of solar alternatives to fossil fuels, there has been little hard data on performance. Such data is beginning to emerge from operating solar-energy systems installed under the National Solar Heating and Cooling Demonstration Program. I he findings for four systems are particularly interesting because they represent a range of possibilities- hot water, space heating, space cooling — at both newly constructed and retrofitted installations — and include both active and passive designs operating at a broad sweep of sites: in New Hampshire, Florida, California, and Iowa.