Question 10.3: Consider a home with a total of 10 incandescent lamps rated ......
Consider a home with a total of 10 incandescent lamps rated at 60 \ W. Determine, the energy-saving potential if these lamps are replaced with (i) 13 \ W CFLs and (ii) 7 W LED lamps. The lifespan of the incandescent lamp, CFL, and LED lamp is, respectively, 1,300, 8,000, and 30,000 \ h. Perform the analysis using the lifespan of the LED lamps. Determine the best lamps to use, CFLs or LED lamps, if the costs of the incandescent lamp, CFL, and LED lamp are \$0.30, \$1.50, and \$10, respectively. Assume the cost of electricity is \$0.10/kWh and perform a simple payback analysis.
Incandescent lamps: Over the lifespan of 30,000 \ h, 230 incandescent lamps are needed. The energy cost for using incandescent lamps over 30,000 \ h would be
kWh=230*60*1300*\frac{1}{1000}*0.10=\$1794Thus, the total cost for using incandescent lamps is \$1794 + \$0.30 * 230 = \$1863.
CFLs: Over the lifespan of 30,000 \ h, about 38 CFLs are needed. The energy cost for using CFLs over 30,000 \ h would be
kWh=38*13*8000*\frac{1}{1000}*0.10=\$395Thus, the total cost for using CFLs is $395 + $1.50 * 38 = $452.
LED lamps: Over the lifespan of 30,000 h, about 10 LEDs are needed. The energy cost for using LEDs over 30,000 h would be
kWh=10*7*30,000*\frac{1}{1000}*0.10=\$210Thus, the total cost for using LED lamps is \$210 + \$10 * 10 = \$310.
Therefore, LEDs would be the best option to replace the incandescent lamps even though they are significantly more expensive than the CFLs.