Capacity Factors over the Lifetime of Solar Thermal and Photovoltaic Plants

Abstract

The levelized cost of energy (LCOE) encompasses capital costs, operations and maintenance (O&M), and performance over the lifetime of a power plant. This parameter, important to compare renewable energy projects, is computed assuming an annual relative performance deterioration over the lifetime of the plant. The performance deterioration is revised to reflect operating data of the latest solar photovoltaic (PV) and concentrated solar power (CSP) plants. From data for the largest of these plants built in the United States over the last decade, we note a marked initial growth phase in the performance of PV plants likely originating from a refinement of design and improvement in the O&M, followed by a limited decline, and a stable performance in the CSP plants of the simplest and more reliable parabolic trough (PT) design without thermal energy storage (TES). It is therefore suggested to consider an annual performance deterioration 0–0.25% for novel photovoltaic plants, and 0% for novel CSP plants PT without TES. The performance deterioration of the novel CSP plants of the solar tower design or plants with TES cannot be assessed based on the lack of data. The suggested changes slightly reduce the LCOE of solar plants, by thus making them more competitive with wind plants.