Resource adequacy assessment considering transmission and generation via market simulations

Resource planning (or long term transmission planning) and system adequacy assessment at the RTO/ISO level in an electricity market environment had added more requirements for new computing tools. The decoupled approach of forecasting the performance of a generation portfolio (LOLE-based) given its historical outage information combined with a deterministic approach to transmission planning based on N-1 criteria present major weaknesses in that the consequences of multiple component failures and the probabilities of single components failure are excluded from consideration. Other considerations that are excluded are a number of uncertainty factors such as load forecasts, location of future generation and fuel price forecasts in addition to social, political and environmental issues and their impact on electricity price volatility. As a result system adequacy is understated which at best leave system operators, at times, with not enough available resources for secure and reliable operation, which in turn lead to high system congestion and inefficient use of resources, and at worst leads to an underestimated forecast of future system reliability needs (transmission, generation or demand response resources). This paper presents a resource adequacy approach that evaluates system reliability taking into consideration the combined unavailability of both transmission and generation resources. Using the ABB GridView application, a production cost based market simulation software, which is capable of conducting chronological Monte-Carlo simulations; the overall system resource adequacy was assessed. Effects of including transmission unavailability are illustrated through a market simulation analysis of the NYCA system based on publicly available transmission, generation, and demand data. This approach is not meant to replace the N-1 based criteria; it will only provide an added dimension to the transmission planning process.