Limits on cloud-induced fluctuation in photovoltaic generation

The cost and the effect on utility reliability of rapidly changing PV (photovoltaic) generation on a partly-cloudy day were investigated. When cloud shadows move across a PV array, the array´s power output is reduced. It resumes full production when the shadow moves away. The utility must follow these changes with other types of generation. Under certain cloud conditions, these changes can be large and fast. A methodology is presented to assess the cost of such fluctuations in PV generation and their effect on a utility´s ability to serve its load. A case study of one large utility in Kansas is performed using this technique