Johanna Mathieu and Anna Stuhlmacher receive HICSS Best Paper Award for work on the potential of drinking water networks as flexible electric loads

Johanna Mathieu and former student Anna Stuhlmacher (MS PhD ECE ‘19 ‘23) won a Best Paper Award in the Electric Energy Systems track of the 2025 Hawaii International Conference on System Sciences (HICSS) for the paper “Demand Response Potential of Drinking Water Distribution Networks.”
Both the demand for and the production of electrical power fluctuates, especially as utilities start to use more and more green power sources like wind and solar. The cost of electricity increases during peak hours, when demand is high, and utilities companies often offer a variety of rate plans to incentivize users to offset their load on the grid to off-peak hours. However, the flexible adjustment of power use by energy-intensive city infrastructure can enable further optimization, resulting in improved power grid reliability, more green energy use, and cost savings. Stuhlmacher and Mathieu focused on the potential of drinking water distribution networks as flexible electric loads.
“The electric grid and the drinking water distribution system are both critical infrastructure systems that we rely on, and so examining both of these systems and the interactions between them is interesting to me,” said Stuhlmacher, now an assistant professor at Michigan Technological University (Michigan Tech).
The drinking water distribution network operates through a system of pumps and water tanks. The pumps are a load on the power grid, requiring electricity to push water through the pipes into the elevated tanks, which use gravity to keep the water flowing when the pumps are off.
Current best practices for operating the pumps go by rules of thumb—for example, running them at night when demand for power is low. However, Stuhlmacher said, the pump system could be optimized based on real-time factors like the proportion of green electricity production and electricity costs. This could also reduce strain on the power grid and ensure its reliability, providing benefits for both the infrastructure and the consumers.
Stuhlmacher and Mathieu used data from Wisconsin and Arizona to estimate the flexibility potential of drinking water distribution systems in both states, and extrapolated their results to the U.S. as a whole. Their calculations demonstrated that U.S. drinking water distribution systems represent a significant untapped resource as a flexible electric load.
“Anna has been doing work on water network flexibility for a long time, and people have been questioning whether this is a large enough resource to care about. This paper tries to get at that issue—we find, yes, it is big enough. It matters,” said Mathieu, associate professor of Electrical and Computer Engineering. “And so, hopefully, that also means that the industry will take this opportunity more seriously and realize that there’s a lot of existing value that we’re not leveraging.”
In practice, such flexibility could be implemented through existing Supervisory Control and Data Acquisition (SCADA) systems integrated into most urban water utilities. SCADA systems allow for data monitoring and process automation, so they could be programmed with additional flexibility. However, changing policies and protocols isn’t that easy.
“I think some of the challenges to taking advantage of water system utilities as a flexible electric load include providing enough support and enough resources that these utilities are comfortable changing their operation,” said Stuhlmacher. “Their first and primary goal is making sure they’re delivering safe, clean drinking water to customers; cost is secondary to that.”
In the paper, Stuhlmacher and Mathieu emphasized the potential value of better characterizing the interconnection between power and drinking water distribution systems. The authors are also beginning to start conversations with cities, which control many of the large community water utilities, and other key players in the energy sector.
“I think what makes water networks exciting is that the resources are very dispersed but they’re all controlled by the water network operator,” said Mathieu. “So, if you got buy-in from the water sector to do this, you’d have a reasonably-sized resource at your fingertips.There are not many examples of these larger-scale distributed resources that are owned and operated by one entity.”
Stuhlmacher will be continuing this work at Michigan Tech, improving the estimates of flexibility potential to account for factors like seasonal changes in water availability and use, regional network differences, and water quality considerations. She is also interested in streamlining the process of calculating these estimates so that they can be estimated in real time by everyday computers without compromising accuracy.