2. The Need Prevent food from spoiling Reduce food-borne diseases Store crops for sale at a later date Store vaccines

3. Varieties There are two different types of solar refrigerators. Type 1 Developed by NASA, uses solar panels to power a normal refrigerator. Type 2 Developed by Emily Cummins, uses evaporation to cool items.

4. How It Works Type 1 Uses the sun’s energy to create free electrons and holes in a semiconductor material causing current. This current is used to power a normal refrigerator. Coolant is compressed, cools, condenses, expands, and vaporizes cooling the coils. Solar Cells are expensive.

5. How It Works Type 2 Consists of cylinder inside another with water soaked organic material in-between. Outer cylinder is composed of any material with holes to let the sun through. Inner cylinder is made of metal. As organic material heats up the water evaporates, removing heat from the metal cylinder. CHEAP!!! SIMPLE!!!

6. How It Works

7. Needs/Abilities Type 1 Can cool contents to 38 degrees Fahrenheit Can use stored power to maintain temperature for a week without sunlight Needs 5 hours of sunlight per day Type 2 No moving parts Can cool contents to 43 degrees Fahrenheit Needs lots of sun to work CHEAP!!!!

8. Who Needs Them? Places that do not have a ready supply of electricity Poorer Countries Research Stations Street Vender Food Carts Hunting Lodges

9. Works Cited http://www.solarpowerwindenergy.org/2009/02/04/st udent-invents-solar-powered-fridge-for-developing- countries/ http://www.solarpowerwindenergy.org/2009/02/04/st udent-invents-solar-powered-fridge-for-developing- countries/ http://home.howstuffworks.com/solar-powered- refrigerator1.htm http://home.howstuffworks.com/solar-powered- refrigerator1.htm