1. Energy Efficiency Reducing the amount lost—also known as increasing efficiency—is as important to our energy future as finding new sources because gigantic amounts of energy are lost every minute of every day in conversions.

7. Energy Conversion Devices

8. Energy Conversion Devices

21. Energy Conversion Devices and Useful Energy

28. Efficiencies of common energy conversion devices

34. Conservation of Energy Chemical Energy in Fuel Electricity (Useful Energy) Waste Heat Total Energy In = Total Energy Out 100% Use Energy Input = 35% Use Energy Output

37. Overall Efficiency of a Light Bulb

40. Cost Comparison between LEDs, CFLs and Incandescent light bulbs $652.50 $159.75 $95.95 Total cost for 50k hours $52.50 $19.75 $35.95 Equivalent 50k hours bulb expense 42 5 1 Bulbs needed for 50k hours use $600 $140 $60 Cost of electricity (@ 0.20per KWh) 3000 700 300 KWh of electricity used over 50,000 hours $1.25 $3.95 $35.95 Cost per bulb 60 14 6 Watts per bulb (equiv. 60 watts) 1,200 hours 10,000 hours 50,000 hours Light bulb projected lifespan Incandescent CFL LED