Hobus, I.1, Kolisch, G.1, Pyro, P.1 and Schäfer, M.2, 1Wupperverbandsgesellschaft für integrale Wasserwirtschaft mbH, Germany, 2Institute of Urban Water Management, University of Kaiserslautern, Germany
(free)Abstract
In the future, an additional potential of control reserve as well as storage capacities will be required to compensate fluctuating renewable energies. The operation of energy systems will change and flexibility in energy production and consumption will rise to a valuable asset for system operators. Wastewater treatment plants (WWTPs) are capable to provide this needed flexibility, not only with their power generators but also in terms of the energy consumption of aggregates on the plant. In a research project funded by the German Federal Ministry for Education, Research and Technology (BMBF), the participation and contribution of WWTPs to such a volatile energy market was investigated.
Keywords
Control energy, energetic flexibility, load-shifting, power-to-gas, wastewater treatment plants.
Introduction
Water and energy systems are strongly linked but act and are managed in most cases independently. Power is needed to pump, purify, distribute and use water – so is water used to produce and use power. In the future new challenges will arise due a high share of fluctuating renewable energy generation leading to an additional need of control reserve as well as storage capacities. The needed flexibility is defined into two effective directions:
Widely available wastewater treatment plants (WWTPs) with anaerobic sludge digestion could provide with their electrical consumers, power production via combined heat and power (CHP) units as well as gas storage the needed (energetic) flexibility (Schäfer et al. 2016). In addition, the integration of new technologies like power-to-gas could increase this amount of flexible energy. In Figure 1 the described interaction of WWTPs to provide energy or to use energy depending on the fluctuating renewable energy production in the power grid is shown.
The possible contribution of WWTPs on energy markets was investigated on the Radevormwald WWTP, Germany. In a first step an aggregate management was developed and suitable aggregates for flexible application were identified (Schäfer et al., 2017). On this base, the influence of a flexible operation of the wastewater treatment on elimination efficiency, energy production and external procurement over a longer period was assessed with the help of dynamic simulation. The results of the dynamic simulation were then again verified in practical application at Radevormwald WWTP. A detailed summary of the project results is given in Schmitt et al. (2017).
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