Investment Model for Renewable Electricity Systems (IMRES): an Electricity Generation Capacity Expansion Formulation with Unit Commitment Constraints

Fernando J. de Sisternes,

November 2013

This paper describes the formulation of IMRES: an electricity generation capacity expansion model with unit commitment constraints in which decisions pertaining to investment, unit commitment and energy dispatch are taken jointly. The purpose of this model is to determine the minimum cost electricity generation capacity mix in systems with a high penetration of intermittent renewable energy resources, while accounting for the operational dynamics of thermal units and their impact on total system cost. The model is formulated as a 0-1 MILP, taking capacity decisions at the individual power plant level, and accounting for techno-economic considerations such as ramp constraints, startup costs, and minimum stable outputs of thermal plants, among others. Additionally, the model offers the possibility of introducing in the system other dynamic elements such as storage or demand side management, that facilitate renewable integration and reduce the total system cost.