Energy conservation is often a matter of good maintenance and housekeeping. Sometimes it's a matter of good sound construction techniques or wise landscaping (for shading). The Department of Energy has a great site, (geared towards homeowners, but useful for hotel owners too) called Energy Savers that will give you lots of ideas about where and how you can save energy. Here is a short list of energy conservation tips you can use at your hotel.
In addition to traditional conservation of energy techniques, there are other steps you can take. Capture the heat by-product and use it to heat water or air. Visit the Department of Energy's site on Energy Efficiency and Renewable Energy for more ideas. Another informative site is Waste Reduction in Energy Conservation.
Energy conservation is good business because it saves money, helping your bottom line.