Step 2 - Develop Net Present Value economic analysis Use the spreadsheet you have developed to evaluate the Net Present Value of the economic case below. Each element of what is listed below must be entered at the appropriate location on the spreadsheet. 1. An energy conservation option has a first cost of $55,000. It requires $500 per year in maintenance and saves $7,500 in utilities. 2. The option will last 15 years with no salvage value. The following interest rates apply: energy cost escalation of 5% annually maintenance cost escalation of 2% annually salary escalation of 3% annually 3. The discount rate for the NPV analysis is 7% and is compounded daily. 4. The energy conservation option is in a building with 20 occupants who have an average personnel cost of $75,000 annually. Assume initially that the investment has no impact on worker productivity