Embedded generation: ESB distribution network considerations

ESB Customer Services operate the distribution networks for the Irish Republic. The distribution networks include some 110 kV circuits, all of the 38 kV sub-transmission network, the medium voltage 10 kV and 20 kV networks along with LV networks. Traditionally, the distribution network has been used purely for load transmission down to lower voltage levels. The only generation was small scale hydroelectric power plants with local network connections, along with CHP installations which generally did not export power to the network. In common with many European utilities, significant amounts of generation from renewable energy sources will be connected at distribution voltage levels in the coming years. In Ireland, the Alternative Energy Requirement (AER) offered contracts for 111 MW of renewables to be connected by the end of 1997. Current government policy is to offer 1997 contracts for 38 MW of renewables each year for the next three years, with a possible extension of this scheme until 2010. Therefore, up to 600 MW of renewables could be connected by 2010. This represents a significant generation capacity, given that ESB´s maximum winter demand only recently topped 3000 MW