Photovoltaics Effective Capacity: Interim Final Report 2

We provide solid evidence, based on more than 8 million data points, that regional photovoltaic (PV) effective capacity is largely unrelated to the region's solar resource. We confirm, however, that effective capacity is strongly related to load-shape characteristics. The load- shape effective-capacity relationship appears to be valid for end-use loads as small as 100 kW, except possibly in thecase of electrically heated buildings. This relationship was used as a tool to produce a U.S. map of PV's effective capacity. The regions of highest effective capacities include (1) the central United States from the northern Great Plains to the metropolitan areas of Chicago and Detroit, down to the lower Mississippi Valley, (2) California and western Arizona, and (3) the northeasternmetropolitan corridor. The features of this map are considerably different from the traditional solar resource maps. They tend to reflect the socio-economic and climatic factors that indirectly drive PV's effective capacity: e.g., commercial air-conditioning, little use of electric heat, and strong summer heat waves. The map provides a new and significant insight to a comprehensive valuation ofthe PV resource. We assembled preliminary evidence showing that end-use load type may be related to PV's effective capacity. Highest effective capacities were found for (nonelectrically heated) office buildings, followed by hospitals. Lowest capacities were found for airports and residences. Many more data points are needed, however, to ascertain and characterize these preliminary findings.