FLOW

The energy transition is fundamentally changing the European electricity system. The expansion of wind and solar energy is leading to greater fluctuations in electricity supply, causing very low or very high electricity prices to occur more frequently than in the past. Flexible energy sources are therefore becoming increasingly important for maintaining a balance between supply and demand in the electricity system at all times. Hydropower plants offer a high degree of flexibility and storage capacity. In practice, however, their operation is often guided by the current situation. Forecasts regarding weather, inflows, renewable energy, and electricity markets have so far been incorporated into decision-making only to a limited extent. Existing uncertainties are therefore not systematically taken into account during operation, meaning that economic potential remains untapped.

Integrating Planning and Operations Across All Time Horizons

The FLOW collaborative project is developing planning and control approaches that integrate weather, inflow, power output, and market forecasts into the operation of hydropower plants. In the long term, the project analyzes trends in energy systems and electricity markets to assess the future role and economic viability of hydropower and to support investment decisions.

In the medium term, the integration of seasonal climate and renewable energy output forecasts—covering periods ranging from weeks to months—into market simulation models will be tested. The study will examine whether price signals and storage values can improve the dispatch planning of hydropower plants.

For short-term operations, FLOW develops automated schedules covering 24 to 48 hours that take into account electricity prices, renewable energy generation, and technical, environmental, and water management requirements.

Concrete Benefits for Practical Applications and the Energy System

Building on this, new operational management approaches for integrated water and energy systems—which take ecological and economic constraints into account—are being developed and implemented as robust assistance systems for control rooms. In addition, using the Danube cascade as an example, a fully automated water management control system is being developed and implemented at LEW Wasserkraft’s Gersthofen control room; this system takes into account technical, environmental, and licensing requirements and optimizes electricity generation.

The most important contributions of the e²n department are:

1. Hydropower in the Transformation of the Energy System
   • Development of Simplified but Realistic Hydropower Models for Large-Scale Energy System Models
   • Application of Bilevel Optimization to Improve the Representation of Real-World Operational and Market Behavior in Aggregated Hydropower Models
   • Analysis of transformation pathways for the European energy system (e.g., through 2030–2050), taking into account uncertainties such as weather, inflows, costs, and import dependencies
   • Assessment of hydropower’s contribution to CO₂ reduction, security of supply, flexibility, and cost-effectiveness compared to alternative flexibility options such as battery and hydrogen storage
2. Using Seasonal Climate and Power Forecasts for the Operation and Marketing of Hydropower
   • Investigation of the benefits of seasonal forecasts for the operation and marketing of hydropower
   • Development and testing of methods for integrating seasonal forecasts into decision-making and electricity market models
   • Implementation of the identified and validated integration approaches for seasonal forecast information into a European electricity market model
   • Assessment of the economic and systemic added value of seasonal forecasts for power plant dispatch, electricity prices, and hydropower revenues across various scenario constellations