E.ON Sverige (Sweden)

Over the past few years, the increasing global population and climate change have intensified pressure on existing waterbodies, with many regions experiencing both water shortages and prolonged periods of water stress. As a result, the demand for reliable, detailed information on water availability and storage has grown rapidly. Despite this, many of the hydrological models used today either do not explicitly represent storage or operate at scales too coarse for practical water management.A clear example of this can be seen in Sweden. Historically largely spared from water scarcity, the country has in recent years experienced recurrent shortages and increasing water stress, particularly in the southern regions. Traditional water storage assessments have relied on S-HYPE, the national adaptation of the widely used HYPE model (Hydrological Predictions for the Environment). Like HYPE, S-HYPE is a semi-distributed catchment model used for flood and drought forecasting, water quality assessment, and evaluating hydromorphological and climate change impacts. While S-HYPE can estimate total storage at the catchment scale, the current setup does not support assessments of individual waterbodies, severely limiting the model’s usefulness in providing in-depth information about local storage changes.To address this, we explored a modified version of the Australian Water Resources Assessment Landscape model (AWRA-L). A case study was conducted on three lakes in the Lagan River catchment in southern Sweden to evaluate the model’s performance and applicability. Initial results showed generally good performance, with an average NSE of 0.68 and a KGE’ of 0.64. However, systematic differences between simulated and observed storage were noted. Preliminary analysis indicated that surface runoff is a major contributor to these residuals, while the influence of individual model parameters remains unclear. It is also uncertain whether the model fully captures all relevant processes under varying climatic conditions, particularly during cold periods.This study aims to improve the model by combining physics-informed parameter optimization with detailed residual diagnostics. First, a randomized one-at-a-time sensitivity analysis was conducted to assess the overall contribution of the various input variables used to calculate the surface runoff. Parameter optimization was then performed using physics-informed rating curves constrained to physically plausible ranges, and optimized inputs were used to recalculate surface runoff. Model performance was evaluated against previous simulations, with residuals analyzed for systematic biases and potential missing processes using statistical and machine learning methods. Finally, temporal and seasonal patterns, autocorrelation, and correlations with auxiliary variables such as air temperature were analysed to identify model deficiencies and areas of improvement.

The population growth and the resulting increased food demand resulted in more intense agricultural practices. This resulted in significant changes in land use and a substantial rise in phosphorus inputs to aquatic systems over the past few decades, primarily through fertilizer application and runoff. Lakes, particularly those situated within agricultural landscapes, now face an increased risk of eutrophication due to elevated nutrient inputs. This poses serious threats to water quality, ecosystem health, and the services these freshwater systems provide. Degraded water quality, algae blooms, which deplete oxygen and threaten aquatic life, are serious ecological consequences. Beyond these impacts, decreased recreational value and complications for drinking water production are effects to the human usage of such water sources. Even though the main drivers of eutrophication are fairly well understood, the dynamics within the lake, especially the mobilization and the release of phosphorus, are poorly known. Lake Vomb, located in southern Sweden, is an important drinking water resource for 5% of the Swedish population. Mitigation measures have been implemented within the lake's catchment, with limited effect on the lake's P concentration. The lake regularly experiences harmful algal blooms affecting the lake’s ecosystem as well as drinking water production, which increases the necessity for further management measures. Previous studies have indicated that internal P loading continues to sustain the lake's high P concentration, particularly during the summer. Furthermore, this appears to be coupled to physical forcing, such as wind direction. To implement successful measures is only possible when the internal dynamics of the phosphorus in the lake are fully understood. To analyze the pathways, patterns, and future development of phosphorus levels in the lake together with the effluent water quality, a multidimensional model of Lake Vomb has been developed. The model combines long-term monitoring data of hydrology, in-situ measurements of total phosphorous, determining water quality parameters, and publicly available meteorological data. Modeling was performed using a combination of the open TELEMAC-MASCARET model with the WAQTEL module. Possibilities to extend the model through the application of the AED2 library are explored and analyzed. The results of the model analysis will be used to optimize lake management strategies, including the placement of nature-based mitigation measures. In addition, current drinking water treatment methods and strategies will benefit from increased understanding of phosphorous transport. Finally, the concept of this specific model and results may be applied to other regions facing similar problems.

Abstract Increases in organic content and the resulting browning of freshwater are a current and growing challenge for the ecology of these waters, leading to the need for more efforts in drinking water production. This study investigated the implications of short-term changes in the water quality from Lake Bolmen on the treatment process at the downstream located at the Ringsjö water treatment plant. The main objective was to understand short-term organic matter fluctuations to efficiently manage drinking water treatment. The ability to make predictions about expected raw water quality based on variations in the watershed and upstream waters facilitates optimal adjustment of drinking water treatment processes. Key elements in the water supply system studied included a tunnel and pipeline system and a sub-basin of Lake Bolmen. A wealth of data were available for the analysis to establish temporal and spatial properties of the water quality in the system and its dependence on the governing factors. The main factors controlling water quality were identified, both regarding the transport in the tunnel and through the sub-basin, including surface runoff, hydrodynamic properties, sedimentation, resuspension, and biomass availability. Although a particular case was investigated, the study has implications for improving drinking water treatment.

Abstract The aim of the current work was to analyze the effect of retrofitting vortex generators (VGs) on the blades of a constant RPM, pitch‐regulated, megawatt‐sized turbine suffering from surface roughness. Engineering modelling and experimental work were utilized, indicating that the degradation of energy production may be mitigated by the VGs. The modelling results indicated that the optimal configuration of VGs to maximize the annual energy production (AEP) depends on the degree of severity of surface roughness. Depending on blade surface condition and turbine characteristics, installation of VGs on an incorrect blade span or installation of too large VGs too far out on the blade may cause loss in the AEP. Therefore, engineering modelling is necessary before VGs may be retrofitted on a specific turbine. The modelling results indicated that the worse blade surface, the more gain may be obtained from the VGs. The work included a full‐scale experimental validation of the present engineering model, lasting 27 months and comprising six turbines where VGs were mounted on three, each with a neighboring turbine as a reference. The turbines were analyzed in pairs, and the influence of the VGs was judged upon the relative difference in energy production before and after the installation. The reason was to limit measurement uncertainty. The results showed that all three turbines increased their energy production after the installation. Results from the three pairs showed an average increase in the energy production of 3.3%, being satisfactorily close to the average 2.8% predicted by the present engineering tool.

Hard water with salts of Ca and Mg may cause scaling, and is often softened. Water with toxic substances, e.g. heavy metals, is harmful, and is often treated with different filtering methods, nowadays often reverse osmosis (RO). There are more than 21,000 desalination plants around the world, providing more than 350 million people with drinking water, and there are more to come. RO-treated waters without pH-adjustment tend to be corrosive; causing elevated levels of metals released from especially pipes, e.g. Pb, Fe and Cu, but also lack minerals, causing decreased daily intake and loss of minerals from the body. Even pH-adjusted RO water has very low mineral content. Food boiled in such water also tends to lose minerals. There are indexes to be used as guides to choose a re-mineralization method after RO. However, methods used today don’t take mineral levels in treated drinking water preferable for human consumption into account, as corrosion aspects are only considered. Treatment with dissolution of dolomitic-calcitic limestone (free from toxic elements) giving 30–80 mg/L Ca, 100–300 mg/L HCO3, 10–50 mg/L Mg and 25–100 mg/L SO4, with Ca/Mg 2–3:1 would be preferable for drinking water production.

The built environment accounts for a significant share of energy consumption and energy efficiency in this sector is important for the Swedish environmental objectives. Only a limited share of the total new construction of multifamily houses are constructed as low-energy buildings. Current building regulations lay down requirements for energy efficiency for new construction, and these will be tightened further in the future. Public housing companies often aim to be at the forefront, and the public housing sector has now built half of Sweden’s low-energy blocks of flats. Many public housing companies have tried, but it is uncertain if they will, or have, the possibilities to construct low-energy buildings on a large scale. Twenty public housing companies around Sweden have been interviewed with the aim of identifying obstacles and possibilities to be forerunners and build better than required by the building regulations. The study shows that the public housing companies build better than the law demands and intend to continue doing so. Low-energy buildings are particularly suitable in central locations where land is attractive and the required returns lower. The driving motivation is to be at the forefront and to build green. The new pressure to increase house building can lead to a risk of energy and quality issues being passed over. For the increase in the construction of low-energy buildings to continue, extended, shared and comparable decision making support for the public housing companies is needed.

This study explores the internationalization processes of small firms operating in the medical technology cluster in the Rhône-Alpes region in France. The study demonstrates that both the location and the sectoral type of industry cluster influence the internationalization and network dynamics in the cluster. In addition, both local and international networks influence firm internationalization processes in different ways. First, the firm life-cycle, industry and locational cluster dynamics determine the extent of network influence on firms' internationalization processes. Second, two types of internationalizing firms emerge in this study: born global firms, led by proactive entrepreneurs and globally market-orientated firms from inception, and born-again globals, which engage in late but rapid internationalization as a result of new management or foreign acquisition. Third, local networks in the cluster are important for influencing the internationalization of the born global firm at inception. In contrast, international networks serve as the main impetus for re-launching internationalization for the born-again globals. Fourth, the local research institutions and their connections abroad help both born globals and born-again global firms develop and internationalize their innovations rapidly in the global marketplace.

Load shedding as the last resort to avoid a major power system breakdown has been utilized for a long time, mainly triggered by under frequency or under voltage relays and actuated by distribution system circuit breakers. Deregulation, dispersed generation, load growth and the ever increasing dependence on reliable electricity supply of modern society have forced the need for more intelligent load shedding, as a means to preserve system integrity and provide acceptable system performance. The aim is to provide smooth load relief, in situations where the power system otherwise would go unstable. The paper covers theoretical work based on customer categories, load pattern and computer simulations, as well as field measurements in a radially fed distribution system, with a large impact of dispersed wind power generation. The measurements are performed with phasor measurement technology to capture also the dynamic properties of large wind power farms in a fairly weak system. The paper addresses indicators of imminent power system instability, advanced methods to smoothly reduce load -with and without communication, including some dynamic price based mechanisms, dynamic load response due to change in supply voltage or reactive power support, power system response due to change in load and impact of dispersed generation in power systems in transition towards an instability. The results in the paper are based both on theoretical studies and field measurements.

Abstract Simultaneous recordings of telluric current fluctuations in pipe-to-soil potentials were made at nineteen locations along the gas pipelines in southern Sweden. During the recordings, bonds across insulating joints were switched in and out to vary the electrical length of pipeline sections, and examine how pipeline length influences telluric current effects. The largest potential variations occurred at the ends of electrically-connected sections with a null point in the middle of the section. Changing the joint configuration significantly altered the position where the largest potentials occurred. Model calculations accurately reproduced the potential profiles obtained from the observations.