Solar collection systems mounted on the roofs of commercial and municipal buildings continue to grow in popularity around the country for building tenants and the financial institutions positioned to provide the lease financing for this environmentally friendly energy solution. The benefits of leasing transactions for roof-mounted systems are growing because installation costs are becoming more attractive, due in part to various state rebate programs and the increasing cost of electrical energy. The Cost Factor As of 2006, the average industrial price for electricity in the United States was 6.16 cents per kilowatt hour, with some states, such as Hawaii and Washington, D.C., coming in at almost 18 cents per kilowatt hour, according to the Energy Information Administration.