If you are buying a solar energy system, make sure your panels can be easily adjusted. As seasons change, so does the angle of the sun. Your panels will need to be adjusted every three months or so. Make sure that you know how to do this or talk to your contractor about seasonal maintenance.
University of Maine Cooperative Extension discusses how to seal leaks in your home.
Look into solar powered appliances. There are a number of products that are available that are powered by solar energy. One of the most popular is the solar powered water heaters. Just having one appliance run by solar energy can save you hundreds of dollars each year in energy costs.