Tor Haakon Bakken

Demonstrating a new framework for the comparison of environmental impacts from small- and large-scale hydropower and wind power projects.

Climate change and the needed reductions in the use of fossil fuels call for the development of renewable energy sources. However, renewable energy production, such as hydropower (both small- and large-scale) and wind power have adverse impacts on the local environment by causing reductions in biodiversity and loss of habitats and species. This paper compares the environmental impacts of many small-scale hydropower plants with a few large-scale hydropower projects and one wind power farm, based on the same set of environmental parameters; land occupation, reduction in wilderness areas (INON), visibility and impacts on red-listed species. Our basis for comparison was similar energy volumes produced, without considering the quality of the energy services provided. The results show that small-scale hydropower performs less favourably in all parameters except land occupation. The land occupation of large hydropower and wind power is in the range of 45-50 m(2)/MWh, which is more than two times larger than the small-scale hydropower, where the large land occupation for large hydropower is explained by the extent of the reservoirs. On all the three other parameters small-scale hydropower performs more than two times worse than both large hydropower and wind power. Wind power compares similarly to large-scale hydropower regarding land occupation, much better on the reduction in INON areas, and in the same range regarding red-listed species. Our results demonstrate that the selected four parameters provide a basis for further development of a fair and consistent comparison of impacts between the analysed renewable technologies.

Submarine Groundwater: A New Concept for the Supply of Drinking Water

Submarine groundwater is water stored under the sea-bed. It might exist in large quantities and can have much lower salinity than the ambient sea-water. Therefore, it may be considered as a potential source of raw water for drinking water supply. This article assesses the feasibility of practical use of these resources. The hydro-geological potential and economical factors are discussed, and a technical concept for the withdrawal, transport and treatment of the water is presented. Based on these factors, we propose that submarine groundwater can be a potential substitute for desalination of sea water, in terms of comparable or lower cost potential. Furthermore, we expect energy efficiency gains and thus also higher environmental performance in terms of reduced CO2-emissions, compared to desalination of sea water based on fossil fuel. We foresee no major environmental, social or political barrier in utilising submarine groundwater as a new source of raw water.

Modelling the effects of stranding on the Atlantic salmon population in the Dale River, Norway

Rapid dewatering in rivers as a consequence of hydropower operations may cause stranding of juvenile fish and have a negative impact on fish populations. We implemented stranding into an Atlantic salmon population model in order to evaluate long-term effects on the population in the Dale River, Western Norway. Furthermore, we assessed the sensitivity of the stranding model to dewatered area in comparison to biological parameters, and compared different methods for calculating wetted area, the main abiotic input parameter to the population model. Five scenarios were simulated dependent on fish life-stage, season and light level. Our simulation results showed largest negative effect on the population abundance for hydropeaking during winter daylight. Salmon smolt production had highest sensitivity to the stranding mortality of older juvenile fish, suggesting that stranding of fish at these life-stages is likely to have greater population impacts than that of earlier life-stages. Downstream retention effects on the ramping velocity were found to be negligible in the stranding model, but are suggested to be important in the context of mitigation measure design.

The Water Footprint of Hydropower Production—State of the Art and Methodological Challenges

This paper reviews published estimates of water consumption from hydropower production and the methodologies applied. Published values range from negative to more than 115 000 m3 MWh−1. Most gross water consumption rates are in the range 5.4–234 m3 MWh−1, while most net values are in the range 0.2–140 m3 MWh−1. Net values are often less than 40% of the gross values, sometimes only 1% of the gross water consumption estimates. The extremely wide range in estimates is explained by an inconsistent methodology and the very site‐specific nature of hydropower projects. Scientific challenges, such as allocation from multipurpose reservoirs, and spatial assignments in river basins with several hydropower plants, affect the results dramatically and remain unresolved. As such, it is difficult to propose “typical values” for water consumption from hydropower production. This paper points out directions of research in order to prepare a consistent and improved methodology for the calculation of water consumption from hydropower projects. This should take into account the role of reservoirs in the provision of a large range of water services, as well as providing regulated power to the energy system.

Simulation of river water temperatures during various hydro-peaking regimes

Hydro-peaking is a type of hydropower operation characterized by rapid and frequent changes in flow, possibly also leading to similar changes in water temperature – http://www.nrk.no/tures (‘thermo-peaking’). This study examines water temperature variations caused by the present hydro-peaking regime in Nidelva River (Norway), and the impacts that future changes in the operations of the hydropower system might introduce. The simulated future scenarios indicate that only limited changes are expected to happen compared to the present situation, measured as changes in accumulated degree-days. The model simulations predict a reduction in the range of 50 degree-days for two of the scenarios and an increase in approximately 40 degree-days for the third scenario. These results are further transformed into changes in salmon egg development and time of hatching, which corresponds to a few days delay in hatching in all three scenarios, and also a slight delay in swim-up for two of the three scenarios.

Modelling the effect of hydropeaking-induced stranding mortality on Atlantic salmon population abundance: Effect of hydropeaking stranding mortality on Atlantic salmon population abundance

Norwegian Institute for Nature Research, Trondheim NO‐7485, Norway Sweco Norway, Trondheim NO‐7030, Norway SINTEF, Trondheim NO‐7465, Norway Correspondence Richard D. Hedger, Norwegian Institute for Nature Research, Trondheim NO‐7485, Norway. Email: richard.hedger@nina Present Address Julian Sauterleute, Dr. Blasy ‐ Dr. Øverland, Beratende Ingenieure GmbH & Co. KG, Moosstraße 3, 82279 Eching am Ammersee, Germany

Using a Bayesian belief network to diagnose significant adverse effect of the EU Water Framework Directive on hydropower production in Norway

We evaluate the multi-criteria methodology employed by Norwegian authorities to screen and prioritise a large number of hydropower licences due for revision of their environmental and production conditions. We structured the national licence screening methodology using the multi-criteria decision analysis theory implemented in Bayesian Network (BBN) software. We show how BBNs can be used to diagnose the overall importance of different criteria implicit in the licence screening projects methodology. The diagnostic analysis finds that hydropower loss criteria were considerably more import than environmental criteria in explaining which licences were given lower licence revision priority. We also use the BBN to assess the trade-offs between environmental impacts and hydropower. Using the licence ranking by Norwegian authoities, we provide an interpretation of the ‘significant adverse effect’ for Norwegian hydropower of achieving Water Framework Directive. The national-level estimates of significant adverse effect are likely to be high, given the limited number of mitigation measures that were assessed in the national screening study. The paper discusses the importance of further regional and local assessment of all available measures to achieve good ecological potential in Norwegian water courses.

Simulation of nutrient reduction scenarios with three different models. Does the selection of model affect the recommended set of measures

Abstract This article compares and discusses the results of applying three different models in order to quantify the phosphorus loads in Kapos catchment, Hungary. The models range from the very simple TEOTIL operating on statistical data and export coefficients, via the semi‐complex INCA‐P to the highly complex and process‐based SWAT. All models have been calibrated with use of basically the same input and calibration data. The models have, to the extent they are capable, been used further to simulate a set of theoretical pollution reduction scenarios. The calibration results showed that all the models are basically able to simulate historical loads of TotP on a catchment level, except maybe those years with particularly high or low loads (INCA‐P in 1999 and TEOTIL in 2002). The scenario analysis showed that the models are to a varying degree capable of simulating the simplified scenarios, where TEOTIL seems to a limited extent suitable for such analysis. This study demonstrated that the selection of model can influence the output of the scenario analysis significantly, and the selection of tool to be applied should therefore be made with great care. The most obvious example is the comparison of the simulation of the reduced runoff from area sources (scenario E) with the simulation of reduced discharges from point sources (scenario F). Based on the simulation results, TEOTIL considers reduction in nutrient runoff from areas to be the most efficient measures, while INCA‐P and SWAT results would suggest focusing on the reduction of point‐source discharges.