Dispatchable Distributed Generation Network - A New Concept to Advance DG Technologies

Abstract

Renewable energy has been booming globally thanks to its economic, social, and environmental benefits. However, small distributed generation (DG) systems using renewable energy have not yet achieved a significant level of penetration. With deregulation of electricity market, policies have been available to facilitate interconnection of small distributed generators (DGs) with electric grids. However, dispatchability and reliability still present technical barriers for small DGs to play a significant role in the open market, thus limiting their ability to provide value-added services. This paper presents a new concept to enhance the dispatchability of DGs through an aggregated DG network. Dispersed DGs with different energy resources, such as wind turbines, photovoltaics, small hydros, fuel cells, and microturbines, are integrated into a single aggregated generating plant via open power transmission networks. Traditional SCADA dedicated optical fibers, copper and other dedicated wireless physical layers can be replaced by Internet access and low-cost point-to-point wireless communication links to reduce infrastructure costs. The aggregated power generation is balanced between firm DGs and intermittent DGs to allow for the required dispatchability. Day-ahead and hourly generation scheduling can be committed in wholesale electricity trading, thereby achieving the desired added economic benefits. This is usually more favorable than being credited at the avoided cost as seen by utilities with traditional individual DGs.