Energy Systems Analysis & Integration

Energy use at wastewater treatment plants is characterised by the dynamic interplay of numerous energy consumers — such as aeration systems, pumps, compressors and agitators — and energy generators, including combined heat and power units, photovoltaic systems and wind turbines. This multimodal system places demanding requirements on the predictability of energy flows, while simultaneously opening up considerable potential for intelligent energy distribution, storage and the realisation of synergistic effects. The amended EU Urban Wastewater Treatment Directive (Kommunalabwasserrichtlinie KARL) adds further complexity. Future requirements will include, among other things, a mandatory minimum level of self-generated energy and a gradual increase in the share of renewable energy in overall consumption. At the same time, tightened limits for nitrogen, phosphorus and organic micropollutants will raise the demands placed on wastewater treatment, resulting in an anticipated increase in energy requirements. This creates a tension between the need for energy efficiency and the ambitious sustainability targets set by policymakers and operators alike.

Addressing these multifaceted challenges requires the use of digital tools. These enable the precise analysis and optimisation of complex process and energy flows, and form the basis for predictive operational management.

FiW supports wastewater treatment plant operators at several levels:

• Short- and medium-term measures: Through energy benchmarking and dynamic energy analyses, we derive quick measures and operational recommendations.

• Complex strategy development: For more demanding optimisation tasks, we employ simulation tools, including specialised software environments such as SIMBA#, STANET, Python, MATLAB Simulink and MIKE.

Using these simulation models, we analyse dynamic load profiles, storage requirements and flexibility potentials — enabling well-founded decisions on the optimised use, storage or provision of renewable energy to other sectors. Beyond efficiency, optimisation is also guided by economic criteria such as cost reduction and load management.

Since 2024, FiW has applied this methodology in project collaborations with partners including WVER, the municipal drainage authority of Cologne (Stadtentwässerungsbetriebe Köln), the city of Wegberg, LINEG and Airbus Operations GmbH. In these projects, the energetic optimisation of wastewater treatment and industrial facilities, as well as the development of long-term future strategies, has been successfully carried out.