In this preliminary study, a system has been identified by which the large amounts of lowgrade waste energy in the primary pollution control system gas :stream can be utilized for comfort heating in nearby communities. Energy is stored in the form of hot water, contained in conventional, insulated steel tanks, enabling a morel' efficient utilization of the constant energy source by the cyclical energy demand. Less expensive energy storage means (heated ponds, aquifers), when they become fully characterized, will allow even more cost-competitive systems. Extensive design tradeoff studies have been performed for the example site, Intalco Aluminum Corporation and the surrounding communities of Ferndale and Bellingham, Washington. These tradeoff studies indicate that a heating demand equivalent to 12,000 single-family residences can be supplied by the energy from the Intalco site. Using a .30-year payback criterion (consistent with utility planning practice), the average cost of energy supplied over the system useful life is predicted at one-third the average cost of fossil fuel