Hydropower unit start-up costs

This paper presents a model for calculation of hydropower generator start-up costs. All start-up costs are assumed to be either directly proportional to the number of starts or increasing with the number of operating hours of the unit. The model takes into account both the direct start-up cost and the effect on the unit´s refurbishment intervals. As each start is assumed to cause abrasion equivalent to a certain number of operating hours, additional costs are incurred as each start reduces the remaining service life of the unit and thus shift the refurbishment intervals closer in time. Introducing a revenue function depending on the number of start-ups in a given period, optimal combinations of start-up rates and service intervals are calculated.