We are currently witnessing a rapid expansion of renewable power production, an increase dominated by wind and solar power. These intermittent energy sources, while having low production costs, increases the uncertainty on the electrical markets. Hydropower is a renewable source of electricity that is capable of controlled production. It is assumed that hydropower will take a more central role in terms of balancing deficiencies caused by intermittent sources. In this thesis, we present a detailed model of a single hydropower plant consisting of 𝑛 turbines. This model is then used as input of solving the optimisation problem of revenue maximisation for the hydro plant owner. The model used takes into account head effects as well as stochastic inflow of water and the stochastic fluctuations of electricity prices.