Info Day Magazine 2026: Energy – Water – The Future - EawagThe role of water in the energy transition

The energy transition should lead to a move away from fossil fuels. This goes hand in hand with the expansion of renewable energy sources, including hydropower. However, this is already widely used in Switzerland. In addition to the climate crisis, which is the main driver of the energy transition, we are also facing a biodiversity crisis.
Tackling both challenges at the same time leads to conflicts that are particularly evident in our bodies of water.

Net-zero strategies, the extraction of raw materials that are critical to the energy transition, and the use of geothermal energy can also have an impact on water. The Eawag research, which we presented at the Eawag Info Day on 8 September and which we address in the following articles, helps to clarify these conflicting objectives and enables us to work towards solutions based on facts. It provides policymakers with the basis for making decisions that are environmentally, economically and socially sustainable.

	«We aim to generate relevant knowledge» The energy transition is taking its toll on our bodies of water. Christian Stamm, Deputy Director of Eawag, explains where the problems lie and how Eawag is helping to find solutions.
	On the trail of Switzerland’s river fish When, where and why do different fish species migrate – and how successfully do they manage to do so despite the barriers posed by hydroelectric power stations? Eawag researchers are investigating this by tagging fish and tracking their signals over a period of several years. Initial analyses have yielded surprising results.
	Choosing the right location for power stations can help preserve habitats Where should hydroelectric power stations be built within a river network if they need to generate a certain amount of electricity but the environmental impact is to be kept to a minimum? This key question is answered by a model that optimises the locations of hydroelectric power stations within a catchment area.
	Hydropeaking: When rivers can no longer find peace Storage power stations are central to the energy transition, but their flexible electricity generation leads to significant, artificial fluctuations in river flow. Eawag researcher Nico Bätz explains what this means for animals and plants, using the River Saane in the canton of Fribourg as an example. Until now, the impact of the high frequency of these sudden fluctuations has been underestimated.
	Lack of dynamics, degraded habitats In sections with residual flow, natural fluctuations in discharge are severely restricted and the connectivity of the watercourse is impaired. This leads to the loss of habitats and biodiversity. Climate change is making the situation worse. However, there are steps being taken to improve the situation
	Residual water: Solid facts rather than heated debates A new database can be used to calculate how residual water flow requirements will affect future electricity generation: The production cuts are smaller than expected. The data set and the methodology developed are intended to assist the cantons in the process of re-licensing power stations.
	Greenhouse gas storage: Check that the lid is sealed Climate targets can only be met if carbon dioxide is permanently stored underground. Researchers at Eawag are investigating at the Mont Terri rock laboratory whether the clay rock found in Switzerland is suitable as a natural barrier for the sealing of such greenhouse gas storage sites.
	Making better use of the geothermal potential in the Alpine region The Alpine region offers great potential for the use of geothermal energy. However, this potential is still largely untapped because development is risky and costly. 3D modelling techniques provide a tool for optimally planning geothermal drilling, targeting potential resources and, at the same time, ensuring the protection of groundwater.
	The energy transition at the expense of environmental justice Critical minerals such as copper, lithium and rare earths are essential for the energy transition. However, their extraction is often water-intensive, as well as harmful and dangerous to people and the environment. In order to identify these local hazards on a global scale and better assess their consequences, researchers at Eawag are developing a new method.
	Energy-saving measures in hot-water systems encourage the growth of Legionella It has been 50 years since the danger posed by Legionella was discovered. A great deal of research has been carried out since then, but many questions remain unanswered – or new ones are emerging. This is because climate change and the associated efforts to save energy create ideal conditions for the bacterium, thereby giving rise to new sources of risk.
	“I’m confident because there is no Plan B” João P. Leitão’s research focuses, among other topics, on how smart water management can make heat waves in cities more bearable. He works with computer models and newly available data sources and likes to contribute original, innovative ideas. Despite the climate crisis and energy challenges, he remains optimistic about the future.
	How energy demand is becoming more flexible When are tenants willing to reduce their energy consumption? And what kind of investments are homeowners willing to make to save energy? Researchers from Eawag and WSL are investigating this through surveys. Their aim is to gauge public support for the design of the future energy system.
	The complex path to a net-zero wastewater treatment plant To deliver state-of-the-art cleaning performance whilst minimising energy consumption, maximising energy production and reducing greenhouse gas emissions as much as possible: wastewater treatment plants face major challenges, as some of these objectives are in conflict with one another, and the whole process must also remain affordable.