4. A photovoltaic (PV) system on a building reduces the peak demand by 25 kW and reduces the annual electricity demand by 60,000 kWh/yr. The PV system costs $32,775 to install, has no annual maintenance costs, and has an expected lifetime of 30 years. The utility rate structure charges $0.07/kWh and $9/kw per month demand charge. a. What annual savings in utility bills will the PVs deliver? b. What is the internal rate of return (IRR) on the investment with no escalation in utility rates? c. If the annual savings on utility bills increases 6% per year, what is the IRR? 4. A photovoltaic (PV) system on a building reduces the peak demand by 25 kW and reduces the annual electricity demand by 60,000 kWh/yr. The PV system costs $32,775 to install, has no annual maintenance costs, and has an expected lifetime of 30 years. The utility rate structure charges $0.07/kWh and $9/kw per month demand charge. a. What annual savings in utility bills will the PVs deliver? b. What is the internal rate of return (IRR) on the investment with no escalation in utility rates? c. If the annual savings on utility bills increases 6% per year, what is the IRR