Economic Comparison of Solar Racking Options to Decarbonize Florida Power & Light’s System

Abstract

With the continued decline of the cost of solar photovoltaics, the importance of optimizing this resource in decarbonization efforts is increasing. In this thesis, we compare different solar racking options to minimize total system cost. We focus this analysis on the flat, tracking, and fixed racking options. We then estimate the Threshold Cost Ratio between each option and Tracking Solar, which dominates utility-scale solar projects in the U.S. For this analysis, we use the Florida Power & Light (FPL) system as a case study, basing our study exclusively on publicly available information. Using the LCOE and a Capacity Expansion Model to compare the different racking options, we conclude that Flat Solar would be preferred to Tracking solar if its cost was 72-77% of the cost of Tracking Solar or lower. For Fixed Solar, this ratio is between 79-84%. Utilities can then use these ratios by estimating the expected Cost Ratio and comparing it to the Threshold Cost Ratio. For example, if FPL estimated that Flat Solar cost 70% of the cost of Tracking Solar per WDC, this analysis indicates that it should mostly build Flat Solar, but if it cost more than 77%, Tracking Solar would be preferred. In addition to lowering costs, evaluating other racking options can significantly reduce the total land needed for decarbonizing FPL since Tracking Solar is the racking option that needs the most land per unit of energy produced.