New probabilistic method for solving economic dispatch and 1 unit commitment problems incorporating uncertainty due to 2 renewable energy integration 3 4

10 Abstract 11 In this paper, a methodology to solve Unit Commitment (UC) problem from a probabilistic perspective is developed 12 and illustrated. The method presented is based on solving the Economic Dispatch (ED) problem describing the 13 Probability Distribution Function (PDF) of the output power of thermal generators, energy not supplied, excess of 14 electricity, Generation Cost (GC), and Spinning Reserve (SR). The obtained ED solution is combined with Priority 15 List (PL) method in order to solve UC problem probabilistically, giving especial attention to the probability of 16 providing a determined amount of SR at each time step. Three case studies are analysed; the first case study explains 17 how PDF of SR can be used as a metric to decide the amount of power that should be committed; while in the second 18 and third case studies, two systems of 10-units and 110-units are analysed in order to evaluate the quality of the 19 obtained solution from the proposed approach. Results are thoroughly compared to those offered by a stochastic 20 programming approach based on mixed-integer linear programming formulation, observing a difference on GCs 21 between 1.41% and 1.43% for the 10-units system, and between 3.75% and 4.5% for the 110-units system, depending 22 on the chosen significance level of the probabilistic analysis. 23