Other
U.s. Department of Energy: Photovoltaics
This site has an overview of PV technology, impact, system application and design. Information is provided on how to select the best solar system for various needs.
State Energy Conservation Office-Texas
State Energy Conservation Office: Learning About Photovoltaic Systems [Pdf]
Explains how photovoltaic systems work and how Texas homeowners are using them. Discusses how a homeowner can use solar energy and still be on the electricity grid system.
Georgia State University
Georgia State University: Hyper Physics: Heat Engine Cycle
The heat engine cycle is defined and discussed. So pressure-volume diagrams are introduced and their use in depicting the cycles of a heat engine is demonstrated. Informative graphics are accompanied by reason-filled explanations.