I need two extrapolated Xcel spreadsheet calculations

General information for the business: We sell an install LED lighting in the commercial sector
Description of excel work: When we currently do a proposal for a client the results from an Excel spreadsheet show 1/. Reduction in Carbon Footprint 2/. Payback period in terms of when the investment in the LEDs breaks even and 3/. The energy reduction per year in %. All these calculations are based on the client's existing electricity price per kilowatt Hour. I want to able to show these calculations taking into account that energy prices will rise by a %tage each year which in turn will reduce their payback period.

In addition, should a potential client not invest in installing LEDs, I want to be able to show him how much money he would have saved on a periodic contact basis, say every 3 months calculated daily.
Extra notes: I currently have Excel spreadsheets for the initial calculations