Balancing wind power fluctuations
In countries like the United Kingdom, the Netherlands and the Scandinavian countries renewable energy resources have already been integrated into the existing electricity infrastructure. The major electricity producers and traders are, however, obliged to make predictions of their production and consumption on a daily basis and communicate them to the transmission system operator. Wind power, like many other sources of electric power, is a technology of variable output. Although it is subject to the risk of under- and overproduction, this variability can become a problem only if it results in unreliable predictions. To minimise deviations of the predicted from the actually produced electric power for a portfolio of wind parks, the Imbalance reduction system was developed at the Energy Research Centre of the Netherlands. The Imbalance reduction system makes use of distributed, intelligent sensing systems to collect all the information needed to coordinate demand and supply in electricity distribution grids. At the heart of the system is the PowerMatcherTM, which provides guidance to an aggregated set of electricity producing and consuming devices towards a common objective. In this simulation environment, each electricity-producing device is represented by a producer agent that can bid on an electricity exchange market. A software agent acting on behalf of the local grid's substation is offering prices for electric power produced and consumed, while client agents represent the demands for electricity. As the demands of combined heat and power systems (CHPs) and house occupants are strongly dependent on the time of year, climate scenarios have also been incorporated for representative periods. PowerMatcherTM has been validated in real-life experiments, where the load variations in the electricity distribution network with residential micro-CHPs were sought to be minimised. For this purpose, the operation of both electricity producing and consuming devices was modified to increase the overall match between production and consumption. As the application of PowerMatcherTM has yielded very encouraging results, further large-scale field experiments have already been programmed.
