1. Thermal Heat Transfer in Solar Panels Tech Topic Krista Miller 03/06/2007

2. Permeation of Glass Where does Heat Transfer Occur? Into Thermal Fluid Power in Panel

3. Permeation EmissivitySolar Absorption AET Solar AE32.08.96 Black Majik.07-.10.95-.98 Morning Star.09-.15.92-.96 Different types of Low-E coatings have been designed to allow for high solar gain, moderate solar gain, or low solar gain. In our case, high solar gain!

4. Power into Panel Efficiency = intercept + slope (Ti-To)/(Io) Where intercept & slope are given as panel specifications, Ti is temperature in the panels, To is outside temperature, and Io is the solar radiation (based on location & day). Multiplying this times the solar radiation (in watts) will give you total Watts out of the system – the harnessable energy. For any specific solar panel, one can graph efficiency using the equation:

5. Power into Panel (Graphs)

7. Thermal Capacity of Fluid In order to calculate how much thermal energy you can store in a specific fluid, Specific Heat * Density * Meters^3 per gallon * flow rate * Minutes per second = Power per Degree Celsius J * kg * m^3 * gal * min = Watts kgC m^3 gal min sec C

8. In Conclusion Heat transfer needs to be taken into account when selecting solar panels Heat is transferred: through glass / surface, into panel, into fluid Specifications are your friend!

9. Sources http://www.lyondell.com/html/products/ markets/coolants/technical_information/ www.wikipedia.org http://aetsolar.com/ http://www.off- grid.net/index.php?p=483 Summary of SRCC certified solar collector… System Ratings