A traditional (incandescent) 60 Watt light bulb has a brightness of about 700-800 lumens. Incandescent bulbs are being phased out in many countries due to their low energy efficiency. The same brightness can be obtained using more efficient light sources, such as a 14 Watt CFL (Compact Fluorescent Light) bulb or an 8 Watt LED (light-emitting diode). For the rest of this exercise consider a light fixture with 3 lights that is in use an average of 4 hours per day. a) How much energy is used by this light fixture in the course of one year when using regular light bulbs, CFLs, or LEDs, respectively? Express your answers both in Joules and in kWh (kiloWatt hours).
b) The average Massachusetts residential electricity rate is 22.85 cents per kWh. How much money is saved in the above case when replacing the regular light bulbs with CFL or with LED bulbs, respectively? [1]
c) According to the US Energy Information Administration, about 0.92 pounds of CO2 are emitted to produce 1 kWh of energy. How much CO2 is saved per year when replacing the bulbs as described above (for both CFL and LED)?