Studies have shown that hotels use 195 gallons of water per average overnight guest. This is nearly twice the rate of water use compared to the use per person in a home setting. Many hotels are located in areas that are naturally water stressed. Reducing the amount of water used per overnight guest is important for both environmental and economic reasons.
For this assignment, you will calculate the costs associated with using conventional showerheads at the Xavier Hotel, and compare that to the costs of using low-flow showerheads instead.  
1.All 450 of the guestrooms in the Xavier Hotel have six 75-watt incandescent lightbulbs. Each occupied guestroom uses the lights for six hours. With occupancy at 67%, how much does the Xavier Hotel spend per day on electricity to light its occupied guestrooms? Assume that electricity costs $0.18 per kWh.
Follow these steps to work through this calculation:

Number of guestrooms × Occupancy = Number of occupied guestrooms
Lightbulbs per room × Watts per bulb × Hours used per day / 1000 = kWh used per guestroom per day
Number of occupied guestrooms × kWh used per guestroom per day = kWh used per day by all occupied guestrooms
kWh used per day by all occupied guestrooms × Cost of electricity per kWh = Cost to light all occupied guestrooms

2.The Xavier Hotel is considering replacing the six incandescent lightbulbs in each guestroom with six 12-watt LED lightbulbs. Each occupied guestroom would still use the lights for six hours, and the occupancy would still be 67%. How much would the Xavier Hotel spend per day on electricity to light its occupied guestrooms, if it switched to LED lightbulbs? Assume that electricity costs $0.18 per kWh.
Follow these steps to work through this calculation:

Number of guestrooms × Occupancy = Number of occupied guestrooms
Lightbulbs per room × Watts per bulb × Hours used per day / 1000 = kWh used per guestroom per day
Number of occupied guestrooms × kWh used per guestroom per day = kWh used per day by all occupied guestrooms
kWh used per day by all occupied guestrooms × Cost of electricity per kWh = Cost to light all occupied guestrooms

3.How much does the Xavier Hotel spend per year on electricity to light its occupied guestrooms with incandescent lightbulbs?
Follow these steps to work through this calculation:

Cost to light all occupied guestrooms with incandescent lightbulbs per day × 365 days = Cost to light all occupied guestrooms with incandescent lightbulbs for one year

4.How much would the Xavier Hotel spend per year on electricity to light its occupied guestrooms if it switched to LED lightbulbs?
Follow these steps to work through this calculation:

Cost to light all occupied guestrooms with LED lightbulbs per day × 365 days = Cost to light all occupied guestrooms with LED lightbulbs for one year

5.How much electricity (in kWh) would the hotel save per year if it switched all of its guestrooms to LED lightbulbs?  
Follow these steps to work through this calculation:

kWh used per day by all occupied guestrooms with incandescent lightbulbs – kWh used per day by all occupied guestrooms with LED lightbulbs = kWh saved per day by using LED lightbulbs
kWh saved per day by using LED lightbulbs × 365 days = kWh saved per year by using LED lightbulbs

6.How much money would the hotel save per year if it switched all of its guestrooms to LED lightbulbs? Assume that electricity costs $0.18 per kWh.
Follow these steps to work through this calculation:

kWh saved per year by using LED lightbulbs × Cost of electricity per kWh = Money saved per year by using LED lightbulbs