An Improved MIP Formulation for the Unit Commitment Problem

In this paper, we present an MIP formulation for the Unit Commitment problem that leads to significant computational time savings and almost-integral solutions when compared to the state-of-the-art formulations in the literature. Using a variety of test instances from the literature, we provide empirical evidence that the polyhedral structure of the new formulation is tighter than the polyhedral structure of the state-of-theart formulation. An important consequence of the new formulation is that it allows us to solve real-life instances of the problem in less than ten minutes on an ordinary desktop PC. In comparison, the state-ofthe-art formulation is unable to provide a provably optimal solution in two hours of computing time on the same machine.