In recent years, as the large-scale deployment of renewable generation gathers paceand the contribution of conventional power generation (gas, coal and nuclear) to electricity supply dwindles, popular concern over grid stability and reliability has grown substantially. Are electricity grids getting less reliable as renewable percentages increase? Should countries and regions be investing in significantly more conventional generation to provide reliable backup? In the traditional model of a national electricity system – widely used for more than 50 years – large conventional gas, coal and nuclear generation plants supply large centres of demand. Power generation is then adjusted upward and downward, or additional power stations brought on line, to meet the changing pattern of demand. In this approach, demand is completely passive, meaning that balancing the system is solely the responsibility of the supply-side. However, electricity systems are in a period of rapid evolution. More generation is being installed at the distribution network level – chiefly, solar PV and smaller wind generation. Greater levels of interconnection are being developed across regions, allowing electricity grids to access more diverse supplies. Demand-side response and aggregation services are being offered by larger quantities of industrial and commercial users, and the roll-out of smart meters should allow domestic users to participate in the future. Energy storage is dropping quickly in price and installations are increasing rapidly. These technologies and services are increasingly allowing the system to be balanced in ways other than increasing or decreasing supply. It is, therefore, more useful nowadays to look at grid reliability holistically, as a matter of electricity security instead of security of supply. We find in our paper that increasing the diversity of options available to balance the system, incorporating demand response, storage and interconnection, has the potential to provide electricity security at a lower cost, both in money and in carbon, than simply increasing supply margins. In short, the UK’s electricity system is evolving quickly and the way we are considering electricity security should evolve as well.
Carbon Brief 28th Nov 2017 read more »