Modelling the Nordic Hydro Power System with Spine Toolbox

Abstract: In the Nordic power system, the largest balancing resource is hydro power. For future developments of the Nordic power system with more renewable and varying energy, such as wind power, the hydro power and its limitations must thus be taken into account. To be able to study this, a model with these limitations is needed. In earlier projects at KTH, a model of the Swedish hydro power system was built, but with the interconnected Nordic power system and the large amount of hydro power in Norway, the Norwegian hydro power system also needs to be considered. In this project, a model of both the Swedish and Norwegian hydro power system is built. Most of the data of the Swedish hydro power system is reused from the earlier projects, while new data of the Norwegian hydro power system is collected. Also data of transmission capacities and power generation and consumption for all areas, both in Sweden and Norway, were needed. Most of the data could be found, or calculated from, the Norwegian Water Resources and Energy Directorate, Nord Pool and Svenska Kraftnät. The new model built in this project includes 363 Norwegian and 256 Swedish hydro power plants, divided into four Swedish and five Norwegian electricity areas. The model is built in Spine Toolbox and is an expanded and remade model based on an earlier, smaller model of the Skellefte river, which maximised the profits of sold electricity. In this project the model is changed to instead minimise the spillage and explore the flexibility of the hydro power system. That is, its possibility to adjust its power generation to both variable levels of demand and other sources of power generation without being forced to spill water. The results from the simulations were hourly values of water flow between hydro power plants, discharged water and spilled water, electricity flow from each hydro power plant and between electricity areas, and reservoir volumes in each reservoir. From this, the simulated production in Sweden, Norway and all their electricity areas could be compared to real data of energy production. This comparison showed that the total simulated production was very similar to real data when factoring out import and export. The spillage and reservoir volumes were also discussed. Further work could improve the models performance, for example adding import and export, implementing minimum reservoir volumes, and base local inflow of water on real data, but overall the model provided promising results. This project has shown that is it possible to build large models in Spine, and adjust them to investigate different cases.