100525 v5 Trust Fund for Environmentally & Socially Sustainable Development Water & Climate Adaptation Plan for the Sava River Basin                                         ANNEX 3 - Guidance Note on Adaptation to Climate Change for– Hydropower August 2015 © 2015 The World Bank 1818 H Street NW Washington DC 20433 Telephone: 202-473-1000 Internet: www.worldbank.org Water & Climate Adaptation Plan for the Sava River Basin ANNEX 3 - Guidance Note on Adaptation to Climate Change for – Hydropower August 2015 ACKNOWLEDGMENTS This work was made possible by the financial contribution of the World Bank’s Water Partnership Program (WPP) - a multi-donor trust fund that promotes water security for inclusive green growth (wa- ter.worldbank.org/water/wpp) and the Trust Fund for Environmentally & Socially Sustainable Development (TFESSD) . DISCLAIMER This work is a product of The World Bank with external contributions. 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Project No. A040710 Document no. 1 Version 8 Date of issue August 2015 Prepared ZAT/DAH Checked RSS Approved BAE Page i Water & Climate Adaptation Plan for the Sava River Basin   Guidance Note on Adaptation to Climate Change for Hydropower    Table of Contents Page No 1  Introduction ..................................................................................................................... 1  2  Climate change impact on Hydropower – Vulnerability Screening ................................. 2  3  Scenarios for climate change in Sava River Basin ......................................................... 3  4  Case studies - Expected magnitude of climate change impact on Hydropower Sector in Sava River Basin ............................................................................................. 4  5  Adaptation and Mitigation Guidelines ............................................................................. 7  5.1  Structural adaptation measures ...................................................................................... 7  5.2  Non-structural adaptation measures ............................................................................... 7  6  References: .................................................................................................................... 8  List of Tables Page No. TABLE 1: HYDROPOWER CLIMATE CHANGE VULNERABILITY ACCORDING TO HPP CHARACTERISTIC ...................................................... 2  TABLE 2: HPPS IN THE SAVA RIVER BASIN USED AS CASE STUDY .................................................................................................  4  TABLE 3: ELECTRICITY CONSUMPTION AND PRODUCTION FROM THE HYDROPOWER SECTOR FOR THE SRB COUNTRIES ............................ 7  List of Figures Page No. FIGURE 1: LOCATION OF VRBAS RIVER BASIN WITHIN SAVA RIVER BASIN ......................................................................................  1  FIGURE 2: RELATIVE CHANGE IN ENERGY PRODUCTION FIVE CLIMATE SCENARIOS CM1‐CM5 AND NEAR AND FAR FUTURE ...................... 5  FIGURE 3: CHANGE OF ENERGY PRODUCTION FOR HPP BAJINA BAŠTA BY SEASONS ......................................................................... 6  Page 1 Water & Climate Adaptation Plan for the Sava River Basin   Guidance Note on Adaptation to Climate Change for Hydropower     GUIDANCE NOTE ON ADAPTATION TO CLIMATE CHANGE FOR THE SAVA RIVER BASIN – HYDROPOWER 1 Introduction This report provides guidance note for decision making on the adaptation needs related to hydropow- er in the Sava River Basin (SRB). This guidance note is one of the components of the Water and Cli- mate Adaptation Plan (WATCAP) being prepared by the Consultant for the International Sava River Basin Commission (ISRBC) under World Bank funding.1 It builds on the main WATCAP report (World Bank, 2013b), the report on the development of future climate scenarios (Vujadinovic and Vukovic, 2013) and on the report on development of the hydrologic model for the Sava River basin (World Bank, 2013a). Thus, the guidance note is designed to provide fundamental and flexible instruction on how to conduct impact and vulnerability assessments in the energy sector, specifically for hydropower facilities along with identification opportunities and entry points for integration of climate change miti- gation and adaptation measures into the hydropower energy (HPE) sector processes. An eminent example upon which this guidance note on the hydropower sector is based is The Inte- grated Water and Energy Nexus Study (IWENS) for the Vrbas Basin, a tributary of the Sava River (see Figure 1), that represents a snapshot of the complex and integrated use, development and man- agement of water resources, in order to meet the water needs of multiple users and their future har- monization as well as adapting to climate change.2 Figure 1: Location of Vrbas River Basin within Sava River Basin 1 COWI AS of Norway were contracted by the World Bank to undertake the development of the hydrologic model – World Bank Contract No - 7162102 2 COWI (2012) Update of the Water Resources Management Basis for the Vrbas River Basin, project report for the World Bank. Page 2 Water & Climate Adaptation Plan for the Sava River Basin   Guidance Note on Adaptation to Climate Change for Hydropower     In order to provide proper information about climate change impact on the hydropower sector various analysis were performed with useful results that define an adaptation strategy direction. Similarly, though less extensive analysis is done for the purpose of completing this Adaptation Guidance note and also by giving an example for conducting a more profound and detailed analysis in the future. 2 Climate change impact on Hydropower – Vulnerability Screening Climate change (CC) impact on the hydropower sector is mainly seen in the effects on power genera- tion potential. Hydropower production would either be positively or adversely affected, depending on the CC effects and how are they managed. Change of three climate parameters as a consequence of CC should be analysed, namely: precipitation, temperatures and evaporation/evapotranspiration (ET). These three parameters are all important components of the hydrological cycle that affects river dis- charge, which in turn is a major input to power generation calculation. Consequently, major projected climate change impacts on the HPE sector are:  Decreased or increased HP generation potential due to more or less precipitation and conse- quently more or less river runoff;  Reduced or increased energy demand for heating or cooling, with regard to CC by means of high- er or lower air temperatures;  A decrease or increase of installed flow for facilities changing HPP effectiveness;  Flooding and landslides damage or complete destruction of HP structures (e.g. dams, transmis- sion and distribution networks) that may create conflict with downstream communities, increase social vulnerability e.g. through involuntary resettlement; and  Energy security and economic development activities will be compromised and production costs will increase. Major vulnerability of hydropower plants and systems to CC lies in change of key parameters for power production, because they are directly linked to climate parameters. Key parameters whose change would largely affect hydropower production are:  River discharge or mean flow and on specific dam profiles: a significant change would affect pro- duction in the same direction;  Duration curves or a fluctuation of discharge in one time period (i.e. year, season,…) for the dam profile: a change would affect the change in total volume used for production and in the same manner production by itself;  Evaporation/ET would affect volume of available water for production. Some characteristics of hydropower facilities affect their vulnerability to climate change. For instance, electricity generation capacity relative change would be decreased or increased in a bigger or a smaller scale depending on the type of facility, size of the reservoir, etc. The vulnerability of different hydropower characteristics to CC are given in Table 1. Using the pattern shown in Table 1, it is possible to define adaptation strategies depending on a spe- cific situation. Table 1: Hydropower climate change vulnerability according to HPP characteristic Reservoir storage area:  HPP type  Reservoir size  Climate  volume ratio  Climate  parameter  parameter  Reservoir  Pumped  change  Run‐of‐river  High  Low  Large  Small  type  storage  Evapo‐ tion/E ra‐ T  Increase                       Page 3 Water & Climate Adaptation Plan for the Sava River Basin   Guidance Note on Adaptation to Climate Change for Hydropower     Reservoir storage area:  HPP type  Reservoir size  Climate  volume ratio  Climate  parameter  parameter  Reservoir  Pumped  change  Run‐of‐river  High  Low  Large  Small  type  storage  Decrease                       Increase               runoff  River  Decrease              Flood        N/A        Temporal   variability  Drought              Seasonal              offset  Legend:     bigger decrease     bigger increase     smaller decrease     smaller increase    3 Scenarios for climate change in Sava River Basin Climate change analysis in Sava River Basin starts with simulations of the future hydrologic regime using a hydrological model for the SRB developed in HEC-HMS. The future climate scenarios are taken from five Global Climate Models (GCM)/Regional Climate Models (RCM) simulations under the A1B Special Report on Emissions Scenario (SRES)/Intergovernmental Panel on Climate Change (IPCC) scenario and are later in text denoted as climate models -CM1 through CM5. With each cli- mate model (CM) daily flows are simulated for three 30-year periods: 1. 1961-1990 (past or baseline climate scenario), 2. 2011-2040 (near future climate scenario), and 3. 2041-2070 (distant future climate scenario). According to work undertaken under this WATCAP study climate change in the Sava River Basin im- plies:3  Temperature increase about 1°C in the near future and 2.3°C in the distant future,  Change of mean annual precipitation ranges between -6% to +4% across the Basin, but seasonal change takes values between -12% to +14% in the near future and as much as -32% to +19% in the distant future, as a mean value for all stations on the Basin. For some parts of the SRB differ- ence is as high as ±30% in near and ±40% in the distant future;  Seasonal variability as described by the 5 used climate models (i.e. CM1 to CM5) is not the same for all. Predictions of two climate model for the near future and three for the distant future indicate an increasing precipitation trend will occur in the winter and a decreasing trend in the summer season. 3 COWI, 2013: Water & Climate Adaptation Plan for the Sava River Basin: Completion of the WATCAP with the construction of a hydrologic model. Page 4 Water & Climate Adaptation Plan for the Sava River Basin   Guidance Note on Adaptation to Climate Change for Hydropower     Taking the information from Table 1 and the overall climate scenario results for the Sava River Basin area overall, the following conclusions can be drawn:  With increasing evaporation/ET, due to temperature increase in the future, a bigger decrease of hydropower production is expected to occur on reservoir type and pumped storage type dams with a high storage area/volume ratio and small reservoirs. Other types of HPP would show smaller effects, but still experience a decrease of hydropower generation;  A decrease in river runoff would affect power generation with a reduction on all facilities but in par- ticular with run-of-river schemes in the SRB because they are highly and solely dependent on riv- er runoff; and  Floods in the fall/winter and droughts in the spring/summer would mostly affect run-of-river HPPs and HPP with small reservoirs. With this climate change parameter an overall power generation decrease is expected. From all of the above it can be concluded that, in the future it would be customary to have lower pow- er generation from the hydropower sector on the Sava River Basin from bigger or smaller schemes, depending on the region and the HPP facility. The magnitude of the change has been reviewed by conducting further analysis through case studies that are described below. 4 Case studies - Expected magnitude of climate change impact on Hydropower Sector in Sava River Basin In the Sava River Basin there are 20 hydropower plants (HPP) with installed capacity larger than 10 MW (see Chapter 2.4.5 of this Report)). Four HPPs were selected as case studies for analysis of CC impact on energy production. The choice of HPP is made based upon the energy production magni- tude and the share in average total energy production in the SRB or in other words upon their signifi- cance in the hydropower sector in SRB area. In addition, data needed for analysis were directly avail- able from the developed Sava River Basin HEC-HMS Model since for each plant location of those four plants there is hydrological station included in model. All four HPPs are reservoir type dams. Table 2: HPPs in the Sava River Basin used as Case Study Share**  Reservoir  Installed  Average  Share* in  in total  Reservoir  storage  capacity  Installed  yearly pro‐ average  installed  Country  HPP  River  volume  area:  [MW]‐ discharge  duction (ref.  total energy  capacity  (mil m3)  volume  ref. year  (m3/s)  2005‐2007)  production  in SRB  ratio  2005  [GWh/year]  in SRB [%]  [%]  Slovenia  Blanca  Sava  9.95  0.13  43  500  144  2.2  1.8  Bosnia and  Bočac  Vrbas  52.1  0.045  110  240  308  4.8  4.5  Herzegovina  Zvornik  Drina  89.0  0.146  96  620  515  8  3.9  Serbia  Bajina  Drina  340  0.036  360  644  1691  26  14.7  Bašta  609 of  Total Sava River Basin (reference  2658/6445      2449 in    41  24.9  year 2005)  total  total  Source: Adapted from the “Sava River Basin management Plan”, Draft version, 2013.  *this refers to share of specific HPP’s yearly average energy production in total yearly average energy production (from hydropower  sector) in whole SRB  **this refers to share of installed capacity of the specific HPP in total installed capacity (from hydropower sector) in SRB  Simulated daily flows for the above mentioned three 30-years periods and five climate models scenar- ios are used to calculate the daily production for selected HPPs, with the following assumptions and generalizations: Page 5 Water & Climate Adaptation Plan for the Sava River Basin   Guidance Note on Adaptation to Climate Change for Hydropower      Efficiency coefficient value for generator is taken to be the same for all HPPs, ηgen=0.95;  Efficiency coefficients for turbines that are used in the four chosen HPPs are: Francis 0.92 Kaplan 0.9  Useable head for energy production and for each dam is taken as a constant for each day’s pro- duction calculation,  All dams are close to dam type and no flow and head losses in the tunnel or penstock are taken into account. Depending on the available daily flow, the flow through the turbines is calculated as: If Qriver  Qinstalled then Qturbines  Qriver If Qriver  Qinstalled then Qturbines  Qinstalled . Energy production is calculated using the formula: E   gen turb  9.81  Qturb  H  t [kWh]  gen -coefficient of generator efficiency [-] turb -coefficient of utilization of turbines [-] Qturb -flow through turbines [m3/s] H -dam head, difference between upstream of the dam water level (in reservoir) and downstream wa- ter level [m] t -time period for which energy is calculated, 1day=24h From the above the daily and yearly productions are calculated. The resulting averages for each 30- year period’s energy production for both near and distant future scenarios are compared in relation to the baseline scenario (period 1961-1990). The results are given in Figure 2.   Source: Figure produced by COWI  Figure 2: Relative change in the annual energy production under A1B emission scenario for five climate model chains CM1-CM5 in near future (left) and distant future (right) The results for all HPPs in the near future show a small expected change in the average annual ener- gy production, with rather small variation between the scenarios except for HPP Bočac. Based on the ensemble median values (as a more robust estimate than the ensemble mean, which might be under influence of extreme values in short samples like this one), an increase in the range of 1-1.5% is ex- Page 6 Water & Climate Adaptation Plan for the Sava River Basin   Guidance Note on Adaptation to Climate Change for Hydropower     pected at two HPPs on the Drina River (Bajina Bašta and Zvornik), and a small decrese is expected at HPP Bočac. HPP Blanca in Slovenia results in 0% change. Greater variation for HPP Bočac gives a power production decrease of 4% with CM4 and an increase of 9% with CM5, thus indicating a higher uncertainty related to the Vrbas basin hydrologic simulations and consequently to the derived energy production. For the distant future the variation between the scenarios is greater, which is expected with the simu- lation period being further away from the observation period. The energy production is expected to change more markedly in this period, between -8% (HPP Bočac) and +4% (HPP Bajina Bašta), alt- hough the order of the magnitude of these changes is still in the range of the modelling and meas- urement uncertainties. The trend at two HPPs on the Drina River (Bajina Bašta and Zvornik) is re- versed and their annual energy production is expected to decrease slightly by 1-2%. The decreasing trend for HPP Bočac continues in this period as well, while the energy production at HPP Blanca is expected to increase. In addition to the results shown in Figure 2, seasonal energy production variability is analysed for HPP Bajina Bašta. These results are portrayed in Figure 3. The near future results show greater en- ergy production in the winter and fall seasons, while in the spring a decrease in energy production is expected. Interestingly, the energy production in the summer season is not expected to change signif- icantly. The distant future results show greater decrease in the spring and summer seasons (by 4% and 10% on average, respectively), whilst in the winter and fall energy production is expected to in- crease by 11% and 5%, respectively, on average.     Figure 3: Change in the seasonal energy production for HPP Bajina Bašta under A1B emission scenario for five climate model chains CM1-CM5 in near future (left) and distant future (right) DJF=December‐January‐February,   MAM=March‐April‐May,   JJA=June‐July‐August,   SON=September‐October‐November    Page 7 Water & Climate Adaptation Plan for the Sava River Basin   Guidance Note on Adaptation to Climate Change for Hydropower     5 Adaptation and Mitigation Guidelines Although predictions of climate scenarios vary over the SRB and by different scenario, it is likely that in the near future no severe alterations of climate that would substantially affect the hydropower sec- tor will happen, while in the distant future water availability would decrease and with it energy pro- duced in hydropower facilities. Although the SRB is predicted to have small (near future) and moderate (distant future) decreases in overall hydropower production as a consequence of CC, these changes are not expected to be se- vere and it is highly unlikely that this would cause detrimental effects on human activities. Further- more, there are other green power sources available (e.g. solar, wind etc.) and a lot of possible measures for adaptation and mitigation to counteract these CC effects. Notwithstanding, on average dependence on hydropower energy for all SRB countries is around 45%, defined as a percentage of hydropower produced from the total energy used (see Table 3 ). Conse- quently, hydropower is very important for the SRB and it follows that work on adaptation and mitiga- tion measures should be started now in order to assure proper and timely resilience to climate change in the future. Table 3: Electricity consumption and production from the hydropower sector for the SRB countries Average yearly electricity  Share of used electricity  Average yearly electricity  production from the hy‐ from hydropower com‐ SRB country  consumption [Billion  dropower sector [Billion  pared to total electricity  kWh] 2000‐2010  kWh] 2000‐2010  consumption [%]  Bosnia and Herzegovina  8.70 5.49 63.15  Croatia  14.12 5.98 42.36  Montenegro  3.37 1.87 55.41  Serbia  28.62 10.49 36.67  Slovenia  12.56 3.73 29.71  Sum:  67.35 27.56 Average 45.5% Data source: U.S Energy Information Administration  Adaptation and mitigation options, both structural and non-structural for the estimated climate change impact on Sava River Basin are summarized below: 5.1 Structural adaptation measures  Enhance dam structural parameters-diverting upstream tributaries to decrease river runoff, new reservoir storage, modifying spillways, changing number and/or types of turbines;  Build robust dams with large reservoirs that can cope with extreme events;  Flexible design for installed capacity;  Consideration of planned structural measures before implementation. This includes all uses of the reservoir (e.g. hydroelectricity, irrigation, drinking water supply, tourism, etc.) before reservoir con- struction or enlargement. 5.2 Non-structural adaptation measures  Consideration of ecological aspects, as structures can generate significant impacts on the water courses (morphological changes, barriers to fish migration, etc.);  Reduce energy demand by promoting public awareness campaigns and training in energy effi- ciency; Page 8 Water & Climate Adaptation Plan for the Sava River Basin   Guidance Note on Adaptation to Climate Change for Hydropower      Improving hydrological forecasting to improve operational rules and utilization of HPP capacity,  Improve operation and maintenance practices at power stations;  Incorporate future reduced or increased generation capacity in design, depending on specific loca- tion on the basin;  Consider using more pumped storage hydropower technology in order to match the energy avail- able to the needs of the consumers and in order to cover peak loads;  Adoption of an integrated water resources and disaster management approach;  Integration of climate change considerations into the management and operation of HE power generation, transmission and distribution system;  Replacement of incandescent bulbs with ones with low energy consumption;  Assess and use other renewable energy production facilities such as wind power or solar power plants;  More profound analysis for most likely estimation of projected climate variations over HPP lifetime;  Identification of cost-effective new designs and modification of existing designs to deal with specif- ic risks for the HPP construction site;  Undertaken regular reviews of permitting and licensing of hydropower schemes to assess river flow regimes and minimum and maximum water levels according to season, to ensure sufficient storage in the reservoir to absorb the spring flood and to tie this into the RBMPs;  Incorporating climate change into existing codes and guidelines concerning hydropower;  Establish a mandatory reporting mechanism for all hydropower companies to provide full opera- tional details on river flow and discharge to improve future monitoring records;  Development of guiding principles on integrating environmental aspects in the use of existing hy- dropower plants such as increase in HPP efficiency, flow regulation, as well as in the planning and construction of new hydropower plants;  Better development / implementation of strict rules (riparian rights) for discharge of water into riv- ers and for water withdrawal. 6 References: 1. Blackshear B., Crocker T., Drucker E., Filoon J., Knelman J, Skiles M. (2011) Hydropower Vul- nerability and Climate Change-A Framework for Modelling the Future of Global Hydroelectric Re- sources, Middlebury College Environmental Studies Senior Seminar. Available at http://www.middlebury.edu/media/view/352071/original/ (retrieved December, 2013). 2. COWI (2013) Integrated Water and Energy Nexus Study for the Vrbas River Basin, Guidance Notes, Project report for World Bank. 3. COWI (2012) Update of the Water Resources Management Basis for the Vrbas River Basin, pro- ject report for the World Bank. 4. COWI (2013) Water & Climate adaptation plan for the Sava River Basin, Completion of the WATCAP with the construction of a hydrological model-Development of the Hydrologic Model for the Sava River Basin, Draft project Report for the World Bank. 5. ISRBC (2013) Integration of water protection in developments in the Sava River Basin (Flood, Navigation, Hydropower, Agriculture), Background paper No. 9 for SRBMP, International Sava River Basin Commission. Available at: http://www.savacommission.org/dms/docs/dokumenti/srbmp_micro_web/backgroundpapers_final /no_9_background_paper_integration_of_water_protection_in_developments_in_the_sava_rb.pdf (retrieved November, 2013). 6. ISRBC (2013) Sava River Basin Management Plan (SRBMP), Draft version, International Sava River Basin Commission. Available at: http://www.savacommission.org/srbmp/en/draft (retrieved November, 2013). 7. UNECE (2009) Guidance on water and adaptation to climate change, United Nations Economic Commission for Europe, New York and Geneva. Available at: http://www.unece.org/index.php?id=11658 (retrieved December, 2013). Page 9 Water & Climate Adaptation Plan for the Sava River Basin   Guidance Note on Adaptation to Climate Change for Hydropower     8. U.S Energy Information Administration (2010) International Energy Statistics. Available at: http://www.eia.gov/cfapps/ipdbproject/iedindex3.cfm?tid=44&pid=44&aid=2&cid=regions&syid=19 80&eyid=2012&unit=QBTU (retrieved December, 2013). 9. USAID (2007) Adapting to climate variability and change, A Guidance manual for development planning, United States Agency for International Development. Available at: http://pdf.usaid.gov/pdf_docs/PNADJ990.pdf (retrieved December, 2013). 10. Vučković D., Melentijević M., Milovanović M. (2004) PostojećestanjeizgrađenostinaslivuDrine, Pregledni rad, Vodoprivreda 0350-0519, 36 (2004) 207-208, p. 39-49. 11. Internet web sites of responsible companies for HPPs with dam specifications data used in the report: 12. http://www.dlhe.rs/latinica/he-bajina-basta 13. http://www.dlhe.rs/latinica/hidroelektrana-zvornik 14. http://www.henavrbasu.com/hev/Doc.aspx?cat=137&subcat=138&lang=cir&id=196 15. http://www.he-ss.si/he-blanca.html