New insights into the ecological effects of sustainable energy help advance the energy transition
Sustainable energy technologies such as solar panels, aquathermal energy and subsurface energy storage affect water, soil and air – and therefore the ecosystems that depend on them. Research shows that floating solar panels can reduce primary production in water: the process by which plants and plankton convert sunlight into energy, forming the basis of almost all aquatic life. The effects of underground thermal energy storage and combined solar and wind energy systems appear, for now, to be limited or location-specific.
These insights help permitting authorities and project developers make better-informed decisions and avoid delays in the energy transition.
Uncertainty hampers progress
For many forms of sustainable energy, knowledge about their impact on nature and ecology is still limited. As a result, permitting authorities such as Rijkswaterstaat, provinces and regional water authorities often need to make decisions despite uncertainty about potential effects.
In practice, this regularly leads to permit applications being delayed or rejected on the basis of the precautionary principle. Consequently, the large-scale deployment of sustainable energy is coming under pressure.
Investigating real-world impacts
Within the Knowledge of Ecology for the Energy Transition (KEEN) programme, Deltares, TNO, Wageningen University & Research (WUR) and KWR are investigating the most important knowledge gaps relating to sustainable energy and ecology. The research focuses on applications on land, in water and in the subsurface.
The researchers combine field measurements at existing installations with modelling. This provides a better understanding of how sustainable energy systems affect water, soil and atmospheric systems. After just one season of monitoring and modelling, several key research questions have already been answered and uncertainty about expected impacts has been reduced. However, monitoring over a longer period than a single season remains essential to capture the full range of natural variation.

Initial findings: impacts vary by technology
The first results show that all of the technologies studied influence their surroundings. The nature and magnitude of these effects vary by technology and location.
- Floating solar panels reduce the amount of sunlight reaching the water. This leads to a clear decline in primary production – the foundation of the aquatic food web – and lower oxygen concentrations beneath the panels. The findings underline the importance of limiting coverage rates in order to minimise ecological impacts.
- Ground-mounted solar panels affect the distribution of rainwater in the soil, creating wetter and drier zones. This effect is highly predictable and can be managed through design and site layout.
- Co-located solar and wind farms show that thermal uplift above solar fields is limited and does not pose an additional risk to birds of prey. Combining these technologies offers opportunities for more efficient land use and may also improve energy generation.
- Underground energy storage systems can cause groundwater mixing. The effects of high-temperature thermal energy storage (HT-ATES) on groundwater quality appear to be limited and location-dependent; groundwater mixing is the dominant factor and requires targeted monitoring and design choices.
- Aquathermal energy from surface water (TEO) can have significant ecological impacts in small, stagnant water bodies, primarily due to cooling and, to a lesser extent, filtration. These processes can reduce primary production and disrupt aquatic systems. Targeted design measures, monitoring and operational flexibility are needed to mitigate such effects.
These insights make it possible to better understand impacts and to develop targeted mitigation measures and design strategies to reduce negative effects.
Direct toepasbaar voor beleid en projecten
The KEEN results provide practical guidance for permitting processes and the design of energy projects.
The combination of monitoring, modelling and collaboration with partners in the field ensures that new knowledge becomes available quickly and can be applied directly in policy and practice.
Sacha de Rijk, ecologist Deltares
A better understanding of ecological impacts enables more transparent and evidence-based decision-making, for example within the framework of the Water Framework Directive and Natura 2000 legislation.
Working together towards a responsible energy transition
The KEEN programme is based on a knowledge agenda identifying the most important knowledge gaps at the interface of ecology and energy. Deltares, TNO, Wageningen University & Research (WUR) and KWR are investigating these questions in the programme initiated by TKI Urban Energy, TKI Offshore Energy and the Dutch Ministry of Economic Affairs and Climate Policy.
The initial findings are based on measurements collected over a limited period and at one or only a few locations. Continued monitoring is required to gain a better understanding of long-term effects and to address the remaining knowledge gaps.
Reports KEEN
-
Collision risks for thermalling birds of prey associated with the installation of solar parks near wind turbines
-
The distribution of soil moisture beneath solar panels on sandy soils
-
Impact of floating solar on water quality : results of a case study
-
Ecological impacts of thermal energy from surface water : cooling and filtration effects
-
Effects of higher temperatures in open ground-source heat pump systems on groundwater quality. (in Dutch only)
-
Assessment of the effects of the Koppert Cress ground-source heat pump system on groundwater composition (in Dutch only)
-
KEEN Evaluation of effects of HTO Middenmeer on groundwater quality (in Dutch only)