Using Wind and Solar to Reliably Meet Electricity Demand

An important aspect of power system planning is ensuring that adequate generation capacity exists to meet electricity demand during all hours of the year. Mechanical failures, planned maintenance, or lack of on-demand generating resources (especially for variable renewable resources) may leave a power system with insufficient capacity to meet demand. Grid planners project future peak demand patterns and estimate the relative contribution of each generator towards achieving a reliable supply of energy. When generating during peak demand periods, variable renewable energy (VRE) such as wind or solar PV provides capacity value to the system. By providing capacity value, VRE can help to defer capital investments in traditional generation and transmission infrastructure.