This web page from American Solar Energy Society (ASES) covers topics including:
- Solar Hot Water Heating
- Solar Electric Systems
- Energy Efficiency Basics
- Wind System Basics
- Ground Source Heat and Cooling Basics
National Renewable Energy Lab (NREL) covers PV, concentrating solar, passive solar, solar water heating, and other topics.
An overview of leases, loans and PPAs from U.S. Department of Energy and Clean Energy States Alliance.