Water cost in electricity generation: Short term operation planning

This paper describes a way to determine the water cost in electricity generation into the context of the short term operation planning in Electric Power Systems. These concepts were implemented in a digital computer package for solving the complex problem of short term hydro-thermal coordination and unit commitment. The package, called CHTS-AU, is a set of advanced application programs and mathematical optimization, developed by the Electrical Research Institute in Mexico. The package is used daily by the Electric Federal Commission (EFC) in the operational planning of the Mexican Electric National Grid (MENG), determining a generation schedule (pre-dispatch) for Hydro and Thermal units in the country. During the operation in real time, occur contingencies that lead to a deficit of power and the need to re allocate generating units, the problem now is to decide which generator Hydroelectric or Thermoelectric is the optimal to cover the deficit, it is therefore necessary to know the water cost and be able to compete against the fuel consumption costs. This paper focuses on the description of algorithms to determine the water cost (economic value of water) and the hydroelectric units models.