Énergie

There is increasing interest in using waterbodies as renewable energy sources to heat and cool buildings and infrastructure. Here, we estimate the potentials for heat extraction and disposal for the main lakes and rivers of Switzerland based on acceptable temperature changes in the waterbodies, and compare them to regional demands. In most cases, the potentials considerably exceed the demand, and minor impacts on the thermal regime of the waterbodies are expected. There are, however, critical situations: rivers crossing densely-populated areas, where demand often exceeds the potential, and heat disposal in summer into lowland rivers and shallow lakes, where temperatures may exceed ecological criteria. To assess the impacts of a realistic thermal use, we model the temperature effects in two lakes: Upper Lake Constance, a large lake with relatively low population density, and Lower Lake Zurich, a smaller lake with high regional demand. The estimated mean temperature alterations are −0.05 to +0.02 °C for Lake Constance, and −0.60 to +0.22 °C for Lake Zurich. Based on the model results, we discuss the effects of operating parameters on the efficiency and impacts of thermal use. Our analysis demonstrates that waterbodies provide real alternatives for heat/cold production in many regions of the world.

Citizens are the target group of sustainability policies, and their acceptance and subsequent behavioral change are key in transition processes. But what drives citizens to accept new instruments that will be added to a pre-existing instrument mix? To answer this question, we suggest an innovative combination of sustainability transitions and social acceptance research, and examine the case of Swiss energy turnaround. We rely on data from a representative sample of the Swiss resident population. By estimating logistic multi-response models, we disentangle individual and context-related factors that drive instrument preferences in a instrument mix situation. We conclude that it is mainly individual factors (values in favor of nuclear phasing out and climate mitigation) that positively impact the acceptance of instruments that promote the larger energy transitions through renewables. Additionally, the self-contribution of citizens (energy pro-sumers) seems to shape preferences more than current policies of their own jurisdiction.

The assessment of ecological impacts of pumped-storage (PS) hydropower plants on the two connected water bodies is usually based on present climatic conditions. However, significant changes in climate must be expected during their long concession periods. We, therefore, investigate the combined effects of climate change and PS operations on water temperature and quality, as well as extent and duration of stratification and ice cover, using a site in Switzerland. For this purpose, a coupled two-dimensional hydrodynamic and water quality model for the two connected water bodies is run with 150 years long synthetic stochastic meteorological forcing for both current and future climate conditions under two PS and two reference scenarios. The results show relevant synergistic and antagonistic effects of PS operations and climate change. For example, hypolimnion temperatures in September are projected to increase by < 0.6 °C in a near-natural reference scenario and by ~ 2.5 °C in an extended PS scenario. Ice cover, which occurs every year under near-natural conditions in the current climate, would almost completely vanish with extended PS operation in the future climate. Conversely, the expected negative impacts of climate change on hypolimnetic dissolved oxygen concentrations are partially counteracted by extended PS operations. We, therefore, recommend considering future climate conditions for the environmental impact assessment in the planning of new or the recommissioning of existing PS hydropower plants.

In Alpine streams, humans have strongly modified the interactions between hydraulic processes, geomorphology and aquatic life through dams, flow abstraction at water intakes and river channel engineering. To mitigate these impacts, research has addressed both minimum flows and flow variability to sustain aquatic ecosystems. Whilst such environmental flows might work downstream of dams, this may not be the case for water intakes. Intakes, generally much smaller than dams, are designed to abstract water and to leave sediment behind. Sediment accumulation then results in the need to flush intakes periodically, often more frequently than daily in some highly glaciated basins. Sediment delivery downstream is then maintained through short duration floods with very high sediment loads. Here we tested the hypothesis that sediment flushing, and the associated high frequency of bed disturbance, controls in-stream habitat and macroinvertebrate assemblages. We collected macroinvertebrates over a 17-month period from an Alpine stream as well as a set of lateral unperturbed tributaries that served as controls. In contrast to established conceptual models, our results showed that the stream is largely void of life during summer, but that populations recover rapidly as the frequency of intake flushing falls in early autumn, producing richer and larger populations in winter and early spring. The recovery in autumn may be due to the recruitment of individuals from tributaries. We conclude that intake flushing in summer inverts expected summer-winter macroinvertebrate abundances, and questions the extent to which environmental flows in intake-impacted Alpine streams will lead to improvements in instream macrofauna unless sediment also is managed.

By studying servitization processes and service competencies in the wind-to-energy industry in European regions, this paper provides a framework for territorial servitization. The framework resonates with the concepts of knowledge-intensive business services (KIBS) and industry life cycles, and its elements can be embedded into concepts of regional development (e.g., lead-market models, sustainability transitions, territorial innovation models). The framework suggests that regions benefit from servitization processes via the interplay of generating employment opportunities, enabling an efficient allocation of technology resources, opening up new markets, strengthening territorial competitiveness, raising the odds of securing employment in the consolidation period and enabling technological leaps.