The verification of existing plans for network restoration after blackouts in European electrical energy systems becomes more and more important with the ongoing deregulation process. For this verification high quality computer models of the electrical system are necessary which are able to generate exact results for all possible restoration scenarios. The most important elements of these models are the power plants, which have to be developed with high accuracy. Therefore in this contribution the possible quality of power plant modelling will be shown exemplarily for a francis type and a pelton type hydro power plant, both located in the Swiss Alps.