Integrating Solar PV in Utility System Operations.

摘要

Deployment of solar photovoltaic (PV) power generation is growing rapidly in the United States. Utilities and system operators are increasingly conducting studies of the impact of PV on operations, including assessments of short-term variability and uncertainty. Consideration of the complex issues surrounding sub-hourly variability and forecasting of PV power output has still been somewhat limited because of the difficulty of creating realistic sub-hourly PV datasets and forecast errors for future scenarios with increased PV production. How utility operations should be changed to more economically integrate large amounts of solar PV power is an open question currently being considered by many utilities. This study develops a systematic framework for estimating the increase in operating costs due to uncertainty and variability in renewable resources, uses the framework to quantify the integration costs associated with sub-hourly solar power variability and uncertainty, and shows how changes in system operations may affect these costs. Toward this end, we present a statistical method for estimating the required balancing reserves to maintain system reliability along with a model for commitment and dispatch of the portfolio of thermal and renewable resources at different stages of system operations. We estimate the costs of sub-hourly solar variability, short-term forecast errors, and day-ahead (DA) forecast errors as the difference in production costs between a case with realistic PV (i.e., subhourly solar variability and uncertainty are fully included in the modeling) and a case with well behaved PV (i.e., PV is assumed to have no sub-hourly variability and can be perfectly forecasted). In addition, we highlight current practices that allow utilities to compensate for the issues encountered at the sub-hourly time frame with increased levels of PV penetration.