This simplified model consists of

This MO model however only considers the maximum output of each power plant and hence neglects ramping constraints, minimum on- and off-times and start-up costs, which are considered in a unit commitment model. As a consequence, power plants may be switched on/off in an unrealistic way in the merit order model. E.g., coal power plants are switched on and off within one hour, while in reality Meissner's corpuscles takes multiple hours for such a power plant to start up. Results obtained with such a merit order model should thus always be interpreted with caution, e.g.