Challenge Water Framework Directive Impact on hydropower

Transcription

1 Challenge Water Framework Directive Impact on hydropower by Karin Seelos Vice President International Affaires Statkraft Energi AS - Power Generation Main challenges Example illustrating challenges and the development of a win-win solution Conclusions OUTLOOK The Mid-Weser region in Northern Germany

2 Results from a member survey in 2010 Huge variation from country to country and between RBMP leads to market distortions due to unequal generating conditions Focus on drinking water and sewage Other water uses not so well considered Apart from UK, unclear distinction between water uses and water services Economic assessment deficient, especially for other water uses than drinking water and sewage Only rough estimates of financial impacts available Biodiversity generally well integrated but harmonised implementation of other legislations or strategies adopted later leaves significant room for improvement (floods, RES, Eels, water scarcity and droughts, adaptation to climate change) Assessment of climate change impacts on PPs rarely considered with the exception of UK Main challenges Uncertainties regarding the environmental effectiveness of proposed ecological enhancement measures Cost/benefit assessment of proposed measures Establishing priorities for intervention according to ecological necessity and economic feasibility Economic incentive programs (e.g. favorable feed-in-tarifs for environmental-friendly power plants) are often limited to size Adminstrative responsibilities between various involved authorities and respective human capacity to assess/manage ecological and socio-economic aspects related to WFD implementation Ecologic continuity can only be achieved if all river obstructions can be overcome: only about 3-20 % of Europe s river obstructions are caused by hydropower installations

3 Are the socio-economic benefits of a heavily modified water body in the balance sheet? Transport: environmentfriendly, low-cost inland waterway Public security: Improved flood/drought protection Energy: climate friendly electricity generation with flexibility to stabilize electric system and to support the integrations of more variable renewables Agriculture: Stabilized groundwater levels have beneficial effects on yields side 5 Is it responsible to expect 50 million uros to be invested into fish migration to achieve possibly good ecological potential? The mid-weser region is designated as a HMWB It is an important federal waterway to establish a connection between the North Sea and the Baltic Sea (500 km inland navigation channel) The run-of-river hydropower plants were built in conjunction with the ship locks, starting in the beginning of 20 th century, and lasting until the 1960ies The ecological potential is classified as bad or not satisfactory according to the River Basin Management Plan, side 6

4 side 7 High costs to improve fish migration without guarantee of ecological effectiveness The cost for improving fish migration in the River Weser was estimated in the Strategy for fish migration in the Weser River Basin Power plant site Estimated construction costs, UPSTREAM [million uros], Quelle FGG Estimated construction costs, DOWNSTREAM and FISH PROTECTION [million uros] Langwedel 2,5 3,4 Dörverden 2,5 2,2 Drakenburg 2,3 1 Landesbergen 2,7 1,3 Schlüsselburg 0,9 1,4 Petershagen 2,8 2,2 Werrawerk 1,9 0,1 Wahnhausen 1,5 0,8 TOTAL 17,1 12,4 Reference: River Basin Commision Weser, FGG Fischfauna Weser Gesamtstrategie Wanderfische in der Flussgebietseinheit Weser. Significant cost beyond construction costs are also expected to be carried by the hydropower operator: Maintenance cost Loss of electricity generation Monitoring costs Measures include: fish passage for upstream migration, turbine management meaning close down of power plant bypasses for downstream migration change of intake trash rack BUT: there is no guarantee that measures for better fish migration will lead to good ecological potential Costs to achieve GEP in a HMWB 8 run-of-river hydropower plants (206 GWh/yr) One-time investment for construction: 41 M Euro Fish passes/ladders: 17 M Euro (upstream migration) Protective grids/trash racks: 24 M Euro Recurrent costs: 4,7 M Euro/year Related increased maintenance 390 k Euro (cleaning of trash racks + deposit costs of debris) R&D (Migromat) 60 k Euro generating loss 4,2 M Euro Estimates for generation losses are varying between 1 and 40 % Major uncertainties regarding which fish species should be able to migrate up and down

5 Not all fish species need to migrate to form a healthy population Diadromous species such as salmon or eel are existentially dependent on migrating between saltwater and freshwater River Weser as federal waterway with North Sea estuary is an important migratory route for diadromous species Potamodromous species (Carp, Zander etc.) are spending their whole life cycle in freshwater and are able to re-establish healthy populations up-and downstream of a dam Improving migratory routes is not critical to their survival. Measures to ensure the health of these populations should focus on water quality and habitats. side 9 Unbalanced focus on fish migration? Perfomance assessment Lack of guidelines and methodology for assessing fish migratory measures across River Basins Ecological-technical best alternatives vs. economic-technical best solution Lack of integration National, regional and local governance levels Energy, freshwater ecology and environmental regulations Cost: 20 million - 1,5 km long Designed for sturgeon, even if no sturgeon lives in the river side 10 Geesthacht fishpass (Elbe river, Germany)

6 Fish friendly trash rack side 11 Ecolocically adverse effects of unproven proposed enhancement measures A common misunderstanding is that the smaller the distances between the bars of the trash rack, the better fish will be protected from turbine inflicted injuries. Yet, by reducing the distance of the bars the attraction forces towards the turbines will increase, what makes it impossible for weak swimmers like the eel to get away from the grid. On larger rivers, the water velocity in front of the trash rack will pose an additional threat to fish. In Wahnhausen hydropower plant, the installation of a 20 mm fish friendly trash rack led to a significant increase of eel mortality. (*) Hübner 2009, Funktionskontrolle eines neuartigen Aalabstieges mit unterschiedlicher Einstiegsanordnung einschließlich des hydraulischen Tests eines neuartigen fischschonenden Rechens Laboruntersuchungen. Pictures: Laboratory test on a 12,5 mm trash rack grid and 0,5 m/s water velocity: Eel is not capable of swimming away and will die either through drowning at the grid or get trapped in the trash rack cleaning machine.(*) Technically adverse effects of unproven proposed enhancement measures Seite 12 The amount of debris floating in the river is usually very high during silver eel migration period (Sept-March) In addition to 24 M Euro of installation costs, the increased amount of debris gathered at the trash rack with smaller bar distances is leading to a reduced water flow on the other side of the grid This entails a high risk for air infiltration into the turbines causing cavity and increased damage risk for rotating machinery This is highly likely to raise: Maintenance costs and Outages Example of a trash rack with a bar distance of 90mm

7 Developping a win-win situation thanks to constructive collaboration between all involved parties Early detection system for eel-migration periods combined with turbine management A pilot project illustrating good practice for developing sound environmental measures by using technical power plant know-how together with scientific fish biological expertise The Research Institute for Applied Ecology has developed the MIGROMAT together with an engineering consultancy and is supportive of the Statkraft initiative on the Mid-Weser. The turbine manufacturer Andritz Hydro has assisted in the programming of the automatic eel-protective turbine operation mode. The efficiency of protective measures, such as the reduction of water flow volume, the opening angle of the turbine blades, the detectability of the migration corridors over weir/gates are not scientifically documented. These open questions will be addressed in a follow-up study on the Weser, supported by the hydropower sector and authorities. Seite 14

8 Early detection system for eel-migration periods The principle behind MIGROMAT is to use eel as a bio indicator for predicting silver eel migration periods. 60 eels are captured from the river and kept in a large tank where water from the river continuously flows through on the power plant site. The behaviour of the eels is continuously registered with a patented marking and detection technique. Based on experience values since 2003, a silver eel migration period in the river can be predicted with a reliability of % thanks to the MIGROMAT. The MIGROMAT enables a targeted turbine management for hydropower plants, in order to protect downstream migrating Silver Eel. side 15 Eel-friendly turbine management MIGROMAT -Alarm Silver Eels swim with the main river flow Generating unit closest to river bank is shut down to increase amount of water in the two more centrally located units Two generating units are operated with high opening angle ( %), in eel protective mode. Expected Silver eel survival rate: 95-98% Expected Silver eel injury rate: Lethal injuries: 0-2% Sub-lethal injuries: 5% Schlüsselburg Petershagen Seite 16

9 Eel-friendly turbine management Goals: Protect migrating Silver Eel from turbine inflicted injuries Minimize loss of renewable electricity generation. Wicket gates Silver Eel (real size) Technical conditions of the Weser hydropower plants: - low head - slow running Kaplan turbines with large diameter - 3 to 4 generating units per hydropower plant side 17 Adjustable Turbine blades MIGROMAT -integrated Turbine management for the Mid-Weser The opening angle of the turbine blades in the Weser power plants is adjustable. With high opening angles of the turbine blades, the risk of bruises against the walls of the turbine s housing is reduced, and the probability of collision with the runner blades is also reduced. A: 3500 mm B: 2000 mm Eel protective turbine management (Source: Dr Ebel 2010) Opening degree Turbine blades [%] Opening space [m] 100 A: 3,5 B: 2 90 A: 3,15 B: 1,8 80 A: 2,8 B: 1,6 70 A: 2,45 B:1,4 50 A: 1,75 B: 1,0 Survival rate Silver Eel [%] Seite 18 There is a documented correlation between the mortality rate and the opening degree of the turbine runner blades (UBA, 2010)

10 Win-win solution for downstream eel migration Ecologically responsible: field experience from Wahnhausen shows since 2003 the reliability of MIGROMAT (80-90 %). Trap and truck might have unknown long-term effects on the Silver Eel. Environmentally reasonable: expected 3 GWh/year (1,5 %) of lost renewable electricity generation Economically feasible... - Installation cost/plant 100 k Euro/p - Operation cost/plant/yr 115 k Euro/p/yr - Estimated revenue loss 210 k Euro/yr... if eligible to higher feed-in tariffs for renewables side 19 Survival rate for Silver Eel passing through two Weser hydropower stations (field test) n=438 n=196 n=427 Definite attribution of turbine inflicted injuries not possible n=1040 n=1633 With the implementation of the MIGROMAT -integrated Turbine management, the quota of injured Silver Eels will be reduced. side 20 Source: Field studies at Drakenburg and Landesbergen by Schwevers und Adams 2010

11 Environmental improvement measure or subvention to commercial eel fisheries? In the mid-weser, 65% of the silver eels are catched in the nets of commercial eel fisher downstream of 6 hydropower plants Conclusions Importance to focus in the next WFD phase on more : balanced impact assessments not only the negative impacts on river ecology, but also the positive impacts on the global environment and the benefits for society and the economy comprehensive considerations of water uses and services harmonised approaches between various EU legislations related to water, energy and climate change pragmatic solutions based on scientific field studies sound cost/benefit analysis proven effectiveness beforehand economic incentives for environmental enhancement measures critical ecological elements to begin (ecosystem bottlenecks) water uses which are causing most deterioration collaboration between regulators and the hydropower sector

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