Abstract
As electricity price volatility increases in Europe's transition to a net-zero society, power producers are forced to fully utilize the flexibility of their assets to time the markets in a profitable way. For hydropower producers in cascaded systems, a key challenge is to accurately include the physical properties that describe the flow of water through the system. The flow in pressurized systems and in open channels are governed by non-linear, non-convex, and state-dependent relationships that are difficult to incorporate into optimization tools that are used for decision support. In this paper, the economical impact of including these flow constraints in the short-term hydropower scheduling tool SHOP is investigated. The income in the day- ahead market has been simulated for a hydropower producer in a simplified version of the Norwegian Sira-Kvina system over the whole year of 2021. Comparing the results of a model with detailed flow description and an aggregated version shows that the aggregated model has a total yearly revenue that is 1.2 M€ (1.1%) lower than the detailed model. This difference stems from an overly optimistic production plan that overestimates the amount of power that can be produced by 0.54% because it fails to consider the state-dependent time delay when attempting to time the price peaks in the market.