ENERWA: Energy in drinking water

The safe supply of clean drinking water is one of the most important social tasks. This is associated with considerable use of energy. On average, 16.6 per cent of the total costs incurred by a water company are attributable to energy consumption. The ENERWA research project is recording for the first time how the entire system for supplying drinking water can be optimised from catchment to treatment, storage to distribution, without any loss of quality of course.

Coordinated by the IWW (North Rhine-Westphalia Institute for Water Research), the project partners work in four model regions in NRW: in the Eifel municipal region of Aachen, in the Rheinisch-Bergischer Kreis district, in the Bergisches Land and in the Ruhr region with their typical characteristics. In general, statements can thus be made regarding the supply of water throughout the whole of Germany.

Engine for progress:

  • initial analysis of the energy optimisation potential
  • consideration of the entire system for supplying drinking water
  • developing and testing possible actions for energy optimisation
  • exploiting the storage potential for renewable energies
  • incorporating adaptation to the impacts of climate change

1 of 8

Photo: Ruhrverband

Overflow of the Möhne Reservoir.

The optimisation potential, not only of individual processes but of the entire system, are modelled and analysed. For example, how can such a system made up of various transport, storage and distribution facilities be controlled in a particularly energy-efficient manner? What possibilities do drinking water reservoirs offer for energy production and storage? Such questions are not only simulated in models, but also specifically applied to practice and action options are tested.

Everything is put to the test

In the complex system for supplying drinking water, it is not enough to take the technical possibilities and operational costs and benefits into consideration. Quantity fluctuations at one point always have an effect on other processes within the system. Precipitation forecasts, regional runoff dynamics as well as changes in consumer behaviour must be included in the calculations.

In addition to the quality of the drinking water and the high ecological quality of the water catchment areas, the project also asks about the social impacts. The population is involved in the project and possible effects on quality of life are taken into consideration. For the residents, for example, a fluctuating water level in reservoirs is an issue.

Contribution to the transformation of the energy system

ENERWA is also making an important contribution to climate protection beyond direct energy optimisation: The project considers possibilities for making processes more flexible, e.g. implementing energy-intensive processes when renewable energy is available. In addition to this, reservoirs and water towers offer potential storage for fluctuating renewable energies and promote their integration into the power supply system.

Adaptation to the impacts of climate change

For the water management industry in particular, long-term adaptation to unavoidable climate change is important: They have to deal with high or low water levels and heavy rain and increases in demand during high-temperature periods etc. This is also included in the planning and is incorporated into the action recommendations.


"Within ENERWA, we are searching for new approaches to using the energy potential of water supply systems. Of course, the priority is always the safe provision of clean drinking water. But the reservoirs, water works and distribution networks with their many technical components are also energy storage systems – they hold hidden energy reserves which we are discovering and using within ENERWA."

Dr. Wolf Merkel, IWW, Managing Director

Partners and sponsors

  • IWW Rheinisch-Westfälisches Institut für Wasserforschung gGmbH
  • Forschungsinstitut für Wasser- und Abfallwirtschaft an der RWTH Aachen e.V.
  • Institut für Elektrische Anlagen und Energiewirtschaft an der RWTH Aachen
  • Aquatische Ökologie der Universität Duisburg-Essen
  • Forschungsstelle Bürgerbeteiligung der Bergischen Universität Wuppertal
  • Wupperverband
  • Aggerverband
  • WAG Nordeifel mbH
  • enwor – energie & wasser vor ort GmbH
  • RWW Rheinisch-Westfälische Wasserwerksgesellschaft mbH
  • SYDRO Consult GmbH
  • Rechenzentrum für Versorgungsnetze Wehr GmbH
  • Becker Büttner Held - Rechtsanwälte · Wirtschaftsprüfer · Steuerberater | Partnerschaft
  • Ruhrverband
  • Wasserversorgungsverband Rhein-Wupper
  • Bundesministerium für Bildung und Forschung (BMBF)