Probabilistic power system simulation

In England and Wales, the transmission system is a separately run company which raises revenue by charging for the use of its system in the delivery of electrical energy from generators to consumers. To forecast and to set its use-of-system prices, simulation of power flows over the network well into the future is required. In a `market forces´ economy, such forecasts are notoriously difficult to get right. Consequently, scenario or probabilistic estimates of expected power flows over the network for a range of inputs and outputs over many time periods are employed. The objectives of these use-of-system simulations are: to promote economic and secure system operation; to encourage the optimal development of the network; and to realise the financial targets of the network operator. The authors briefly discuss the two basic methodologies used in probabilistic simulation: Monte Carlo methods and analytical convolution methods