Flexilienz stands for a resilient (resistant) and flexible drinking water supply in times of climate change and the energy transition. The project strengthens supply security in Kassel through innovative technologies and intelligent system coupling.
In the northern Hessian city of Kassel, a versatile water supply system provides high-quality drinking water to around 200,000 residents and numerous businesses. Various extraction methods are used for this purpose – from the spring areas in the Habichtswald and Kaufunger Wald forests to deep wells in Simmershausen and a groundwater recharge facility along the Fulda River. This allows the water supply in Kassel to be operated in a particularly flexible and reliable manner.
However, new challenges are emerging:
- Climate change brings longer periods of drought and more frequent heavy rainfall events.
- Heavy rainfall events impair water quality in headwaters due to turbidity—the water is temporarily unusable.
- Water availability is declining while consumption is increasing.
At the same time, the energy transition is changing the framework conditions:
The increasing share of renewable energies is leading to fluctuations in the amount of electricity in the grid. On windy and sunny days, there is an oversupply, resulting in falling or even negative electricity prices.
However, these developments also present opportunities:
- Innovative, membrane-based treatment techniques now enable cost-effective treatment of raw water that was previously not considered suitable for drinking water supply.
- Flexible consumers, such as pumps and aerators, could be operated specifically when particularly large amounts of electricity from renewable sources are available.
- This would enable a cost-efficient and climate-friendly water supply while simultaneously reducing the load on the power grids.
This is precisely where Flexilienz comes in:
By linking water and energy systems, Kassel's drinking water supply becomes more resilient to the effects of climate change – and at the same time becomes an active part of the energy transition.
Core components of Flexilienz:
- Filtration technologies ensure that spring water remains usable even after heavy rainfall or is drained in a targeted and time-limited manner.
- A pilot electrolyzer extracts green hydrogen from rinse water—a sustainable dual use.
- Forecast models link the electricity demand of the water supply to electricity exchange prices and the supply of renewable energy.
The Kassel real-world laboratory serves as a test environment for transferable solutions that can also be used in other regions – to conserve resources, reduce emissions, and increase security of supply.
