Toward a Comprehensive Economic Comparison Framework for Solar Projects: A Case Study of Utility and Residential Scales

The growing demand for clean energy transitions has become increasingly significant, with solar energy emerging as one of the most prominent clean energy resources contributing to this effort. However, there remains limited knowledge regarding the economic feasibility of solar project development across different geographic locations and scales. This study introduces a comprehensive economic analysis framework to assess the economic viability of residential- and utility-scale solar projects, using California, Tennessee, and Texas as case studies. The economic assessment is conducted through a cost–benefit analysis that adopts a full life-cycle approach, encompassing phases from permitting to demolition for both scales of solar projects. We found that utility-scale solar projects generally offer more favorable investment return ratios (IRRs) compared to residential projects, with IRRs of 0.57 to 0.61 for California, 0.63 to 0.80 for Texas, and 0.11 to 0.52 for Tennessee. Moreover, utility-scale solar projects in Texas were found to exhibit the earliest breakeven point, reaching financial viability by the seventh year. Furthermore, the incorporation of energy storage solutions, such as battery energy storage systems (BESSs), is shown to be essential for improving the efficiency of residential solar energy usage, with efficiency gains of up to 50%. Finally, region-specific strategies, including net-metering policies, electricity retail market structures, and the promotion of solar adoption, play a crucial role in enhancing the financial viability of solar projects for both residential and utility scales.