Integration of customer-owned generation into the electric utility load dispatching technique

The authors discuss the integration of customer-owned generation into the electric utility generation dispatch. They show how high-resolution load and generation data can be used to closely match the supply and demand of electricity, thereby reducing the capacity requirements and overall operating cost. This technique is especially valuable when the customer-owned generation is intermittent in nature, as is the case with photovoltaics. The authors study the load, system generation, and photovoltaic output data for an electric utility in Virginia. The impacts of various levels of photovoltaic (PV) generation on various types of days, e.g. low, medium, and peak load, are shown. It is seen that large amounts of photovoltaic energy do not automatically displace high cost peaking generation. As the peaking generation (e.g., combustion turbines) cannot always change fast enough to accommodate the variable PV generation, the impact is felt on other dispatchable units as well as on hydro and pumped storage. A technique is provided which allows the optimum commitment of hydro, pumped storage, and large fossil units to maximize the utilization of customer-owned generation (such as PV) while keeping the overall cost down