The General Services Administration(GSA) is an independent agency of the United States government, established in 1949 to help manage and support the basic functioning of federal agencies. Besides overseeing $66 billion of procurement annually, some key functions of GSA is to provide office space to federal employees, develop government-wide cost-minimizing policies, and other management tasks. GSA contributes to the management of about $500 billion in U.S. federal property, divided chiefly among 8,300 owned and leased buildings.
This is a VERY USEFUL link to see what each state is offering in regards to rebates and incentives for various Green products and services. Please be aware that these rebates and incentives change frequently for various reasons.