Multi-area generation adequacy and capacity credit in power system analysis

A generator's contribution to the generation adequacy of a power system is more accurately captured by its capacity credit than by its installed capacity. The capacity credit takes into account factors such as forced outages and limited energy supply and the latter is especially important for volatile renewable sources that behave quite differently from dispatchable sources. Their installed capacity gives very limited information about their contribution to the generation system adequacy. Traditional approaches for calculating the capacity credit treat the power system as a single area and calculate an aggregate value for the whole system. In this paper, a multi-area approach is introduced which is able to quantify how the capacity credit is distributed between different power system areas. A combination of an iterative multi-variate Newton approach and a Monte Carlo simulation with an efficient sensitivity analysis allows this to be achieved in a computationally economical way.