Optimal spinning reserve under load and intermittent generation uncertainty using Monte Carlo simulation

The objective of this paper is to find the optimum spinning reserve (SR) in a power system integrating renewable energy sources (RES). Over SR causes higher production cost whereas insufficient SR causes outage cost. Optimum SR should yield lowest summation of production cost and outage cost. In general, load demand may deviate from forecasted load profile whereas RES output is intermittent. These result in uncertainty. This paper employs a stochastic process to encounter uncertainty by using Monte Carlo simulation. It is tested on a 10 unit system plus 1 RES for 24 hour planning. SR is varied 7-12% of forecasted load whereas load standard deviation is varied 6-8%. Input values are obtained by sampling randomly based on normal distribution 1,000 values for each hour, resulting in 1,152,000 simulations for all cases. Numerical results reveal that the optimum SR could be 8% or 11-12% depending on load deviation and outage cost.