Class III
Solar Ovens!
Review of previous class:
New Material
Applications  Energy  Power 
electricity for houses  watt = Joule/second
kilowatthour (kwh) = 3.6 million Joules = 3,413 Btu

kilowatts (kw)
1 Ton = 12,000 Btu/hr 
Heating water  British Thermal Unit (Btu) = 1055 Joules = raise 1 lb of water 1
degree fahrenheit

Therms/hr
watts 
Heating houses 
Therm = 100,000 Btus 1MMBtu = 1 million Btus (10 therms) 1 gallon propane = 91,200 Btu 1 cubic foot natural gas = 1020 Btu 
Therms/hr 
Powering vehicles  gallon of gasoline ~ 34 kwh  1 horsepower = 746 watts 
Output of utility scale wind turbines  megawatthour (mwh)  megawatts (Mw) 
Output of power plants  1 kg coal = 30 MegaJoules  Gigawatts (Gw) 
Powering the human body  calorie = 4.184 Joules; heats one gram of water one degree celsius; dietary calorie is 1000 calories  dietary calories per day 