For each case scenario, calculate (1) the total cost of the project, (2) whether the project would pay for its investment costs and, if so, (3) how long the payback would take, and (4) the annual energy/resource cost savings. Express your answer in years and months. You must show all of your work to get credit. Case #1 (10 pts) Replacing Inefficient Refrigerators. Office headquarters wants to replace 2, 15 year old refrigerators with one Energy Star larger unit. Based on the average watts as the constant electricity use and the other facts provided, what is the total cost for the upgrade? What is the annual energy cost savings? What is the project payback period? Show your calculations for total electricity costs currently and proposed and payback period. Cost of electricity $0.19/kWh Current Appliances: 2 Amana 14 cu ft. refrigerator/freez ers 203 Watts Average electric use/appliance/hour Proposed Replacement: 1 Amana 24 cu. Ft. Energy Star frost free refrigerator 75 Watts $1,399 $0 Average electric use/appliance/hour Appliance cost Installation cost Case #2 (20 pts) Replacing Inefficient Toilets Green Real Estate in Michigan wants to update its 1970s era, 50-unit apartment building with new water-saving tank toilets. Each of the 25 west units has 2-full bathrooms and has 4 occupants and each of the east units has one bathroom and 2 occupants. Assume the national average of 6.20 flushes per person per day. Based on the average flush rate and the other facts provided, what is the total cost for the upgrade? What is the annual water cost savings? What is the project payback period? Show your calculations for everything. Cost of water Flushers/person/day $12.04/kgal 6.20 Current Fixtures 1970s era gravity-fed flush toilets 5.6 gals Average water use/fixture/per flush Proposed Replacements: Kohler WaterSense labeled toilets 1.28 gals $389.00 $10 Average water use/fixture/per flush Fixture cost Installation cost/toilet Case #3 (20 pts) Switching to LED Street lighting Bitsy Corporation wants to replace all of its 32,000 High Pressure Sodium street lights on its 15 Hawaii campuses with energy efficient LED street lights. Based on the average watts over an 8-hour daily operation time and the other facts provided, what is the total cost for the upgrade? What is the annual energy cost savings? What is the project payback period? Show your calculations for total electricity costs currently and proposed. Cost of electricity $0.431/kWh Current Appliances: 32,000 HPS Street lights 150 Watts Average electric use/server/hour Proposed Replacement: Average electric use/server/hour Cost/light Installation cost/light 32,000 SP90 LED Streetlights 36 Watts $80 $1450
