To achieve a stable and reliable electricity supply, efficient provision of reserve capacity or, more generally, ancillary services is crucial. Because of the expansion of wind power with random variation in supply, and expected environmental restrictions in hydropower operation causing reductions in regulated hydropower capacity, the balancing power and system reliability issues have become topical in Scandinavia. Moreover, there seems to be a wide-spread opinion that increase in wind-power generation will lead to increased demand for regulating power, much higher prices for reserves and a much higher value of regulated hydro power. Thus, this chapter deals with the value of balance regulation power, or electricity reserves, in the Nordic electricity market, and we will address the issue of the future value of electricity reserves, hydro capacity in particular, that could be used either for energy production or to balance power production, and more generally discuss the value of balancing power in the Nordic electricity system. In the first, theoretical, part of this study we will apply a simple dynamic electricity generation model, involving hydropower, thermal power and wind power to derive the value of the water in a dam of a hydropower plant. In the second, more empirically oriented, part we will address a number of issues related to balance regulation and the value of balancing power with focus on the Nordic electricity market and against the background of an expanding generation capacity of intermittent renewable electricity, especially wind power.<p>
