1. Thermoelectric Generation by Radiative Cooling of the Earth Adam Vore Stella Kim Jung Hye Lee Jovani Tafoya

2. Overview Need/Purpose Theory Theoretical vs. Actual Data Construction Advantages/Disadvantages Commercial Viability Results/Conclusion

3. Need/Purpose Solar Cells need sunlight Electricity is needed at night Maximizing generated power

4. Theory Atmospheric Window The Atmosphere is clear In the 8-14  m range Most of the radiation of a 300K body is in the “Atmospheric window” Blackbody curve for a body at 300K Governing Equation

5. Theory P Voltage is generated by temperature difference Power is generated by heat flow Governing Equations

6. Theory Heat Flow Governed by Boltzmann radiation law Typical values for T hot and T cold are T hot =15 o C (air temperature) T cold =-50 o C (sky radiometric temperature)

7. Theory 15 o C -60 o C T.E. Generator Photon path 5oC5oC Net Radiation flux out Heat flow

8. Data Performance was better than expected Probably due to Thermoelectric element not covering entire area of emmitter Measurements taken with the following equipment 1 Apogee instruments infrared thermometer for sky temp 1 Vaisala Weather station for air temp 1 Campbell Scientific CR1000 datalogger for voltage measurements

9. Construction Aluminum reflectors Copper Emmiters Foam Insulation Thermoelectric Epoxy Dry ice Voltage meter

10. Advantages ECONOMICAL/ENVIRONMENTAL SUSTAINABLE RESOURCES LESS MAINTENANCE FEE ECO-FRIENDLY

11. Disadvantage LIMITED AREAS LOCATIONS HUMIDITY SEASON

12. Commercial Viability A Football field could generate 50kW For a 1MW powerplant, you’d need 20 football fields At a cost of $2/cm 2 it would cost $66,000,000 per football field Costs would go down with a high level of production Target cost of $30,000 per football field Low maintenance costs (cleaning)

13. Results/Conclusion A football field could power a house (average daily residential use: ) Micro thermoelectric generator can reduce the area required Standard thermoelectric generatormini thermoelectric generator 2.5 mm 2 – 1.2 mm 2 3.6 mm 2 – 38.44 cm 2

14. High start up costs : $50,000 Solar panel : $ 11,500wind turbine: minimum $ 2,000/kW

15. Inexpensive maintenance Cost effective in long-term (Average monthly electricity bill: $95.66) Pays back after 26 yrs

16. Sustainable Environmentally friendly

17. Questions? Please direct all your questions toward Jovani