The potential benefits of strategically located energy storage and integration of power from renewable sources

Ultimately there will be a limit on the amount of power from variable sources of renewable energy which can be absorbed by the electricity supply system and continue to remain stable and secure. New technical solutions are required. The development of energy storage technology could provide a potential solution. However, all the current methods involve either a significant loss of energy during the process or are unsuitable for the bulk storage of power. The research work reviews current methods of energy storage and examines the supply chain in order to resolve where energy storage should best be located. Most benefits could be gained if the energy storage units were placed adjacent to the final customers. The power lost during transmission and distribution could be minimised and the capital invested in the infrastructure would be more productive. It would require energy to be stored in relatively small quantities using simple technology, be remotely controJled and offer a long operational life. Few current methods match these requirements. In order to support the analysis of benefits which may be delivered by storing energy, the performance of a modem CCGT power station was monitored while it was operating with a number of different output profiles. The consequences were recorded and analysed for fuel used, C02 emitted, operational costs and maintenance as the plant produced power below its optimum performance. The Flow Battery was identified as the technology likely to deliver most characteristics required of an embedded energy store. However, the flow battery requires space to store the electrolyte and can be expensive to employ in urban areas where land prices are high. An enhancement of the hydraulic accumulator could be developed as an energy store. The initial analysis suggests that it offers the potential technical characteristics required and could be designed for minimum land requirements. Hence it could be located adjacent to existing electricity sub-stations or even within domestic premises, industrial complexes and commercial enterprises where land may already in the hands of the potential user