Impact of natural gas supply, renewable penetration and demand trends on power system maintenance

This paper analyzes the impact of natural gas supply, increased penetration of renewable energy sources and shifting demand trends due to tight financial conditions on generating unit maintenance scheduling. The main focus is on the increased importance of enhancing unit availability in periods of concurrent peak electricity and natural gas demand and limited RES contribution, through proper adjustment of power system maintenance rules. In power systems with peak demand in summer and high photovoltaic penetration, this translates into enforcing unit availability during winter. A detailed mixed-integer linear programming model for the yearly maintenance scheduling of a System Operator is developed with GAMS/CPLEX in order to evaluate modifications in maintenance rules. The same model is used to assess the consequences of a short-term natural gas shortage contingency scenario, given the maintenance decisions of the yearly scheduling process. The method is applied to the Greek power system.