Good morning,
We are trying to design a PV system for a data center facility in Miami Beach, FL. At first, for Scenario #1, we included the original building demand in kWh resulting in annual energy usage of 2,897,040 kWh, and computing a simple payback period of 9.8 years and a discounted payback period of 14.0 years.
As we wanted to further analyze the financial metrics should the data center load decrease substantially due to migration of equipment to other nearby facilities, we developed Scenario #2 and reduced the original building demand to 10% of the original values, resulting in annual energy usage of 289,704 kWh. However, upon running the calculations, the simple payback period rises to 14.1 years, and the discounted payback period yields NaN (Not a Number).
If the building demand is lower, and the system production actually exceeds the demand values in some instances, why are the simple and discounted payback periods affected so abruptly? Both scenarios yield positive net savings with the system, and we cannot find any major discrepancies in the cash flow tab values to explain the financial losses over the payback period resulting in a negative net present value for Scenario #2.
Can you please help?
Thank you,
JB