Capacity factors of solar photovoltaic energy facilities in California, annual mean and variability

• Main Authors: Boretti Alberto, Castelletto Stefania, Al-Kouz Wael, Nayfeh Jamal
• Format: Article
• Language: English
• Published: EDP Sciences 2020-01-01
• Series: E3S Web of Conferences
• Online Access: https://www.e3s-conferences.org/articles/e3sconf/pdf/2020/41/e3sconf_icsree2020_02004.pdf

The capacity factors of the largest solar photovoltaic (PV) energy facilities of California are computed, based on a low-frequency monthly statistic that is covering the last few years. While the best-performing facilities achieve annual capacity factors of about 32-33%, the average annual capacity factor is less than 30%, at about 26-27%. The scattered information on costs suggests a cost penalty of 35% for a capacity factor gain of 10%. Higher frequency data of 1-minute or less for every facility connected to the same grid and the grid average energy supply are needed to define the energy storage indispensable to cover a given demand. The individual facility energy production requires to account for a cost associated with an energy storage allowance to every producer of intermittent and unpredictable electricity, with this amount inversely proportional to the annual average capacity factor and directly proportional to the standard deviation of the high-frequency capacity factors.