Compute NPV of savings

Your assignment is to take two of the measures and compute the net present value of the savings associated with each of them, computing in a number of ways. 1) First, consider the cashflow where the savings remains constant from 2009 to present with an interest rate of 5% 2) Next, consider a cashflow where the savings were eroded by behavioral or other changes over time. Consider a 10% erosion each year. 3) Next, consider a cashflow in which the savings are computed according to the prevailing electric and gas rates for each year. This is a little more complicated but start with the historic prices for electricity and natural gas in 2009. That will allow you to compute the kWh and BTU savings for each measure (which may be somewhat different from the table). Then use the prevailing rates in the subsequent years to create a cashflow and compute the net present value of that flow. The Energy Information Administration1 and the Idaho Public Utilities Commission2 are good places to look for this information. 

NO PPT IS REQUIRED. ONLY THE CALCULATION WITH LINKED EXCEL S REQUIRED.