The effects of climate change on hydropower generation. Case study: Itaipu Dam

Transcription

1 The effects of climate change on hydropower generation Case study: Itaipu Dam Seminar Paper University of Utrecht Module: Climate System and Adaptation Lecturer: Prof. Hans Middelkoop Submitted by Yannick Oswald, Bram Vonsee We declare that we have authored this seminar paper independently, that we have not used other than the declared sources, and that we have explicitly marked all material which has been quoted either literally or by content from the used sources. Language: English Enrolment numbers: Oswald ( ), Vonsee ( ) Page number only text: 9 Utrecht, Page 1 of 23

2 Table of contents Abbreviations Introduction Research approach Research overview Subjects derived from literature Literature Analysis Climate effects Water inflow Electricity generation Profit Overview results Discussion Framework conditions Identifying most reliable results Implications of the results Conclusion Limitations and Outlook Bibliography Appendix Page 2 of 23

3 Abbreviations GCM IPCC USD MW MWh TWh Global circulation model Intergovernmental Panel on Climate Change U.S. dollar Megawatt Megawatt hours Terawatt hours Page 3 of 23

4 1. Introduction In South America, hydropower generation provides 63% of the total electricity production. This amount makes it the most dominant form of energy production (Van Vliet et al., 2016). Brazil and Paraguay in particular are both very dependent on electricity generation from hydro dams (90%-100%) (Blackshear et al., 2011). The Itaipu dam is a hydroelectric dam in the Parana River, located at the border between Brazil and Paraguay (figure 1). It dam was built in the period of 1971 to 1982 and is run by the company Itaipu Binacional. Figure 1: Location of the Itaipu dam, Source: (Mercosur, 2007) The dam is considered to be very important for both Brazil and Paraguay. This is due to the fact that 75% of the total energy being consumed in Paraguay, is generated by the Itaipu dam. In terms of population, Brazil is 29 times larger than Paraguay. Still the dam accounts for 15% of Brazil s total energy consumption (Itaipu Binacional, 2016c). Given the importance of the Itaipu dam, the assessment of possible climate change impacts on the dam s production is of interest, especially for policymakers. This paper focuses on the influences on electricity generation and economic feasibility. The following research question is approached: Is climate change affecting the Itaipu dam s electricity generation and economic feasibility? Table 1 presents an overview of the dam s most important data. According to installed capacity, the Itaipu dam is the second largest hydroelectric power station in the world, with a total capacity of MW (Megawatt). It generates between and MWh (Megawatt hour)/year (considering data from ). In terms of area and volume, the dam s reservoir is of average size, with 1350 km² of surface area and 19km³ of volume (Itaipu Binacional, 2016d). There are larger reservoirs present in the world, the Guri-dam reservoir in Venezuela for example, but also many smaller ones (Britannica, 2016). However, in terms of water utilization efficiency, the dam performs Page 4 of 23

5 well. With an efficiency of 10.4 MW/km², it is the most efficient dam in Brazil and compared to the Guri-dam in Venezuela, which has an efficiency of 2.5MW/km², also highly advanced (Britannica, 2016). The yearly profit of Itaipu Binacional is over 1 billion USD (Itaipu Binacional, 2016f). This is large, considering the fact that it is the only power plant owned by the company. Parameter Unit Value Source Installed capacity MW (Itaipu Binacional, 2016b) Installed capacity per generation unit 700 MW (Itaipu Binacional, 2016b) Number of generation units 20 - (Itaipu Binacional, 2016c) Production share total energy mix Brazil 15% - (Itaipu Binacional, 2016c) Production share total energy mix Paraguay 75% - (Itaipu Binacional, 2016c) Table 1: Dam specifications and importance Page 5 of 23

6 2. Research approach 2.1 Research overview This is mainly a literature based research. Table 2 has been set up in order to provide an accessible overview on the scientific literature that has been examined. Since literature with a specific focus on the Itaipu lake and the Itaipu dam is limited, this research also took literature with a global perspective into account. In doing so, several expert opinions, models and results could be considered. The first category in the table Study, provides the names of the different articles combined with their publication year. The publication year is important since it is desirable to receive up-to-date insights on the topic. Furthermore, the category Spatial scope was added to clarify the different geographic areas that were analyzed. By doing so, distinction in global, regional or local focusing studies could be made. The category Temporal scope is important for making a distinction between articles that operate across different time-spans. Study Spatial Scope Temporal scope Van Vliet et al., 2016 Global Hamududu and Killingtveit, 2012 Global Scheaffer, 2012 Global Unspecified Blackshear et al., 2011 Table 2: Literature overview South America and Parana river (regional) Moreover, during this research the company Itaipu Binacional, which is in charge of the dam, was approached by . The Division of Hydrological and Energy Studies (OPSH.DT) and the Division of Programming and Production Control (PCCP.TE) replied with regard to our questions. According to Schreier (2012), the questions used (and the subjects these questions approached) followed an inductive and explorative approach. This is because at the beginning of this research, no profound knowledge on possible answers to the research question was given. The structure of the is stated in table 3. The full conversation can be found in the appendix Unspecified Magrin et al., 2014 South-East America (regional) Rivarola Sosa et al., 2011 Itaipu dam (regional) to Itaipu Binacional 2016 Itaipu dam (regional) 2016 Unspecified Page 6 of 23

7 Question How much is precipitation going to change and going to influence the dam's generation patterns? Is it affecting the company's economic situation? Is it affecting the energy security in Brazil or Paraguay? Maybe climate change is causing positive/enhancing effects on energy security? Approached subjects Precipitation + electricity generation Economic situation + profit National implications for Brazil and Paraguay National implications for Brazil and Paraguay Table 3: structure and subjects covered 2.2 Subjects derived from literature During the literature analysis, a general pattern in subjects was noticed. Four major subjects determining the answer for our research question have been identified, namely: climate factors, water inflow, electricity generation and profit. Furthermore, it has been recognized that these subjects relate to each other in the causal order shown in figure 2. Climate factors Water Inflow Electricity generation Profit Figure 2: Subjects derived from literature in causal order Firstly, the climate factors determine the amount of water flowing into the dam. Secondly, the amount of water flowing into the dam determines the amount of electricity generated. Lastly, the amount of electricity generated determines the profit made. In this study, climate factors are considered precipitation (mm/year), temperature ( C) and evaporation (mm/year). Water inflow (m³/s) will be considered the amount of water flowing into the Itaipu dam. Electricity generation (GWh/year) is the amount of electricity generated by the Itaipu dam and profit (USD/year) is the profit that the Itaipu dam makes. These key-parameters determine the order of the next chapter, in which the different parameters will be reviewed one by one, according to the analyzed literature. Page 7 of 23

8 3. Literature Analysis 3.1 Climate effects The first parameter in the causal chain (figure 2) is climate effects. According to the consulted literature, the most important climate effects are considered to be precipitation, evaporation and temperature. The Itaipu dam area (figure 3) currently has an average annual precipitation of around 1650mm/year and an average evaporation of around 1000 mm/year. The average temperature throughout the year is 22 C, with maximum values around 40 C in Summer (November-January) and minimum values around -4 C in Winter (June-August) (Itaipu Binacional, 2016a-g). Considering the climate factors in the current situation, Magrin et al. (2014) make general predictions on climate effects for the Southeastern South America region. This study predicts an increase in temperature (with a range of 1-5 degrees Celsius) and an increase in precipitation (with a range of 5%- 30%). When considering precipitation, Blackshear et al. (2011) agree with high increases in rainfall. Furthermore, a modeling study dealing directly with the Parana river and the Itaipu dam itself was conducted by Rivarola Sosa et al. in Rivarola Sosa et al. (2011) found that, in the long term, precipitation is going to decrease by 2% to 7%. This result is contrary to the one of Magrin et al. (2014). Schaefer et al. (2012) state that the climate variables in Brazil are very likely to fluctuate significantly more than during the current situation. This suggests an increasing uncertainty in hydropower production and even in national energy demand and supply patterns. However, the article states that storage capacity of a reservoir can compensate for seasonal (or even annual) variations in water inflow (Schaeffer et al., 2012). Figure 3: Itaipu lake area Source: (Mapfrappe, 2016) Page 8 of 23

9 In agreement with Schaefer et al. (2012), Itaipu Binacional (2016) stated that a change in precipitation will be dealt with by the cascade of about 50 reservoirs they have upstream. In general, three articles agree on an increase in climate factors and two studies agree on a decrease in climate factors. One article states that the intensity of the climate factors will fluctuate in the future. Finally, Itaipu Binacional (2016) states that climate factors do not change. The overall results on climate effects are very inconsistent as shown in figure 4. Hamududu, 2012; Blackshear, 2011; + Magrin, 2014 Van Vliet et al., 2016 Rivarola Sosa et al., Scheaffer, 2012 Fluctuation Itaipu Binacional, 2016 =0 Figure 4: Literature statements on climate factors Page 9 of 23

10 3.2 Water inflow According to the examined studies, the water inflow distribution is to large extents determined by the climate conditions. The graph in figure 5 depicts the current distribution of water inflow into the Itaipu dam. The dam has an average yearly inflow that varies between 9000 and m³/s. There are inflow maxima in February and June and a minimum in August. The grey and green lines depict absolute maxima and minima which have been measured during the period between 1983 and Figure 5: Inflow distribution Parana river to Itaipu dam (Itaipu binacional, 2016e) (based on data from 1983 to 2013) On the one hand, Van Vliet et al. (2016) state that for South America, decreases in streamflow (-20% to -5%) are expected. On the other hand, as mentioned before, Magrin et al. (2014) expect an increase in temperature and precipitation. Inferred from this information (according to figure 2), is that the river streamflow (including the Parana river streamflow) is going to increase. The researchers furthermore assign a very high confidence to the trend discovered and the expected increases in stream-flows. Though, the description of confidence is of qualitative nature. No quantitative confidence interval is mentioned. Overall there can again be stated that the results on inflow are very inconsistent. The pattern thus repeats itself. At this point, this conclusion is expected to be similar for the upcoming parameters as well. Page 10 of 23

11 3.3 Electricity generation According to the examined studies, inflow directly influences the amount of electricity generation. Currently, the Itaipu dam has an annual generation of GWh/year to GWh/year (Itaipu Binacional, 2016c). For comparison, this is almost three times as much as the Kashiwazaki-Kariwa Nuclear Power Plant which is the largest nuclear powerplant in the world (Wikipedia, 2016). Hamududu and Killingtveit (2012) state that climate change will not lead to significant changes in the global hydropower generation. On a global scale, the hydropower sector is one of the sectors least affected. However, the article declares that climate change might influence the hydropower production of small hydro plants. Hamududu and Killingtveit (2012) declare that this is due to the fact that a large storage capacity provides more flexibility in operations. Since the Itaipu dam has a large reservoir, it is likely to remain unaffected in the future. For the short-term ( ), Rivarola Sosa et al. (2011) project an overall stable development of electricity generation for the Itaipu dam. The researchers look at different time horizons and seasons. For example, the researchers find that in short term, production is going to decrease in autumn (-544 GWh) and winter (-165 GWh) and increase in spring (63 GWh) and summer (601 GWh). At the end, the article points out yearly mean values. For the short term ( ), the overall generation is increasing. During the mid-term period ( ), the pattern changes and the overall production and profits are expected to diminish. In the long-term ( ), this pattern continues and electricity generation is supposed to shrink between 3.74 GWh and GWh per month. The short assumption that was made at the end of the previous paragraph has been validated. Overall there can again be stated that the results on electricity generation are also very inconsistent. At this point, this conclusion is also expected to be similar for the upcoming parameter profit. Page 11 of 23

12 3.4 Profit Rivarola Sosa et al. (2011) directly made a link between electricity generation and profit. For example, a change in electricity generation of -544 GWH resulted in a loss of 54.4 million USD. For the short term, the overall profit is increasing. During the mid-term the situation changes and the overall profit is diminishing. In the long-term this pattern continues and profit is supposed to shrink between USD and 1.4 million USD per month. Itaipu Binacional (2016) declares that its economic situation is not affected at all. The current financial model is based on selling the availability of installed capacity and not only on the actual power production. Thus the company currently receives payments for being available, not only for participating on the market. The most important fact is that there is almost no concrete data available on the dam s profit. The only study that describes the possible changes in profit is Rivarola Sosa et al. (2011). Of course, the information provided by Itaipu Binacional has also been taken into account. The short assumption that was made at the end of the previous paragraphs has again been validated. Overall there can again be stated that the results on profit are also very inconsistent. Page 12 of 23

13 3.5 Overview results Table 4 gives an overview of the examined literature and their outcomes regarding all previously described parameters. The delta symbol ( ) in the table depicts a change in values of the different parameters, in which =0 means no change in value, - means decrease in value and + means increase in value. Study Van Vliet et al., 2016 Spatial Scope Temporal scope Worldwide Hamududu, 2012 Worldwide Scheaffer, 2012 Blackshear et al., 2011 Magrin et al., 2014 Rivarola Sosa et al., 2011 Worldwide South America and Parana river South-East America Unspecified Unspecified Itaipu dam Climate effects Precipitation: - Evaporation: - Temperature: - Precipitation: + Evaporation: + Temperature: + Water inflow Electricity generation - 5%-20% - 5%-15% - Profit % =0 =0 fluctuation + fluctuation + fluctuation + fluctuation + Precipitation: + significant Temp: + significant Precipitation: + 5%-30% Temp.: + 1-5C Evaporation: + Precipitation: - 2%-7% River runoff: Significant + Significant + Significant + Slight + Slight + Slight % GWh/year million profit USD/month to Itaipu Binacional, 2016 Table 4: Results literature analysis Itaipu dam Unspecified =0 =0 =0 =0 Page 13 of 23

14 4. Discussion While evaluating Table 4, it stands out that the results are not in line with each other. Three studies (Hamududu and Killingtveit, 2012; Blackshear et al., 2011; Magrin et al., 2014) predict increases concerning all four subjects (climate factors, water inflow, electricity generation, profit). Two studies (Van Vliet et al., 2016; Rivarola Sosa et al., 2011) predict decreases, one study suggests fluctuations (Scheaffer et al., 2012) and Itaipu Binacional itself forecasts no significant changes at all. This overall result implies a high amount of uncertainty. In order reduce this uncertainty, this chapter firstly discusses the framework conditions of the studies in order to gain insights on the reasons causing diverging results. We discuss the scenario frameworks, the temporal scopes and the spatial scopes. Secondly, the studies which contain the most reliable and reasonable results are identified. Thirdly, these results and their implications are discussed in detail. 4.1 Framework conditions Scenario frameworks: All references evaluated are either based on an A1 or an A2 scenario according to the widely used SRES (Special Report Emission Scenarios) created by the IPCC in 2000 (IPCC, 2000). Both scenario story lines focus on economic development instead of enhancing sustainability in economy and society. The similar scenario stories imply that the range of climate change pathways is not that wide. If one would have to compare an A1 with an B2 scenario it would be certainly wider. Thus the different scenario frameworks are not considered to be the principal reason for diverging results. Temporal scopes: The temporal scope of each study either concerns at least several decades or is meant to cover an unspecified but long-term oriented time horizon. Important to note is that all results displayed concern yearly averages. Additionally, there were no studies that made conclusions on the basis of a temporally higher resolution. Since the temporal specifications are homogenous, they cannot be the cause for diverging results either. Spatial scopes: However, a distinction between global and regional studies is observable. On the one hand, the global studies either include negative outcomes for hydroelectricity production (Van Vliet et al., 2016), no change at all (Hamududu and Killingtveit, 2012) or fluctuations (Scheaffer et al., 2012). On the one hand, there is no global study that predicts an increase in hydroelectricity production within South-East America. On the other hand, two of the regional studies (Magrin et al., 2014; Page 14 of 23

15 Blackshear et al., 2011) conclude on increasing hydroelectricity production and increasing revenues (see Table 4). Therefore, it is very likely that the different spatial scopes and resolutions in modelling cause different outcomes. 4.2 Identifying most reliable results Assuming that spatially higher decomposed studies deliver more realistic results, it is considered that Magrin et al. (2014), Blackshear et al. (2011), Rivarola Sosa et al. (2011) and the response from Itaipu Binacional include the most decent results. However, high quality information can be narrowed down further. Magrin et al. (2014) and Rivarola Sosa et. al (2011) have been identified to deliver the most reliable information concerning climate factors, water inflow and electricity generation. In addition, Rivarola Sosa et. al (2011) and the response from Itaipu Binacional are most suitable for quality insights with regards to profit (Figure 6). Figure 6: Mapping subjects with the most reliable studies This was inferred as follows: Magrin et al. (2014) is a study ensemble made for the IPCC (Intergovernmental Panel on Climate Change). This ensemble consists of 11 studies and of 75 distinct simulations runs in total. This high quantity of diverse simulation runs distinguishes Magrin et al. (2014) from all other references. Therefore, the results are considered to be very close to the best possible guess. The remarkable characteristic of Rivarola Sosa et. al (2011) is its spatial resolution. This study applied data from a GCM which has a resolution of 3.75 degree latitude 3.75 degree longitude. This latitude and longitude size corresponds to an area of km² and was statistically downscaled to areas 29 times smaller. The researchers generated a grid cell resolution of 14.5km² (corresponding to 0.13 degree latitude and longitude). This high resolution is unique so far. As a consequence, the study is considered to display highly realistic output data. Furthermore, Rivarola Sosa et al. (2011) display very concrete numbers on the change of the dam s profit until the end of the century. Again no other reference offers this precision. Another source, Page 15 of 23

16 taken into account for information on profit, is the response received from Itaipu Binacional. The topic was approached by the following question: Is it [climate change] affecting the company's economic situation?. Since we received direct expert information, it is considered to be of high quality. 4.3 Implications of the results Now that the most reasonable results have been identified, it is possible to draft future scenarios. In the following paragraph, two scenario paths are suggested for the impacts of climate change on the Itaipu dam: a pessimistic scenario (base year 2011, end year 2100) and an optimistic scenario (base year 2014, end year 2100) 1. An overview on the scenarios is given in Table 5. The pessimistic scenario is derived from the results in Rivarola Sosa et al. (2011). This study predicts a decrease in precipitation (- 2%-7%) which causes a decrease in water inflow by roughly 15% and thus a decrease in electricity by 12%. The study also predicts a decrease in profit per month of million USD after The following calculation is of interest: If one considers a moderate decrease of 1 million USD in profit per month, one ends up with 12 million USD a year. Considered over a period of 60 years ( ) this amounts to 720 million USD. This is even less than the yearly profit of Itaipu Binacional (Itaipu Binacional, 2016f). This result suggests that the economic situation of the dam will not be endangered by climate change. Furthermore, Itaipu Binacional mentioned that it receives a high amount of installed capacity based payments keeping up the profits. Due to this financial structure, it does not matter if the dam generates any electricity. Consequently, the yearly profit remains unchanged. The optimistic scenario is derived with regards to the results stated in Magrin et al. (2014). This study predicts an increase in precipitation (+ 5%-30%). The wider range of predictions is probably due to the higher quantity of simulations. From this increase in precipitation, an increase in water inflow of about 12% was inferred. Since this study did not derive changes in electricity generation, the relation between changes in water inflow and electricity generation stated in Rivarola Sosa et al. (2011) has been applied to the numbers stated in Magrin et al. (2014). The relation is as follows: If water inflow changes by 15%, electricity generation changes by 12%. This implies that the electricity generation change is 20% lower than the change in water inflow. This relation has been applied to the optimistic scenario as well. Hence electricity generation is likely to increase by 9.5% (since water inflow increases by 12%). Again the profit remains constant for the reasons already outlined in the pessimistic scenario. 1 The terms pessimistic and optimistic are meant to display the dam s perspective i.e. whether it will generate more or less electricity and/or profit. The base years of the scenarios correspond to the year in which the corresponding article has been published. Page 16 of 23

17 By taking into account the national perspectives of Brazil and Paraguay, the pessimistic scenario could have important consequences for both countries. The whole electricity consumption in Paraguay (8.1 GWh/year in 2012) is less big as the decreases in electricity generation which are predicted (roughly 12 GWhyear). Moreover, 75% of its electricity is supplied by the Itaipu dam. Consequently, Paraguay would need to have a priority role within this scenario (EIA, 2016). Otherwise the country would face a severe shortage of electricity. Therefore, it is likely that Paraguay would further receive all the electricity it needs and the missing electricity would mostly be an issue in Brazil. Brazil then would have to compensate for that amount. Considering that Brazil has a roughly an electricity demand of GWh/year, the amount of 8.1 GWh/year would probably be easily replaceable e.g. by other hydroelectric dams or modern renewable energy sources (EIA, 2016). Parameter Unit Current Value Climate factors mm/year Pessimistic scenario Base year: 2011 Precipitation: - 2%-7% Temp.: Undefined Evaporation: Undefined Optimistic scenario Base year: 2014 Precipitation: + 5%-30% Temp.: + 1-5C Evaporation: + Water inflow m³/s Electricity Generation MWh/Year Profit USD/Year 1,103,817,173 Unchanged Unchanged Table 5: Scenarios built on the basis of the discussion Page 17 of 23

18 5. Conclusion Climate predictions and respective impacts on the Itaipu dam are controversial and characterized by high uncertainty. Despite this uncertainty it was possible to generate two likely scenario paths for the impacts of climate change on the Itaipu dam: the pessimistic scenario and the optimistic scenario. River inflow and electricity generation will only change moderately in the pessimistic scenario (river inflow: 15%- ; electricity generation: - 12%) and also in the optimistic scenario (river inflow: 12+ %; electricity generation: + 9%). By examining Table 3, one can conclude that the Itaipu dam will be relatively resilient to climate change. Especially the profit structure will stay stable which is due to its capacity based financing scheme. However, from a national perspective, the changes in electricity generation could be significant. As discussed in chapter 4.2, the pessimistic scenario could threaten the security of electricity supply in Paraguay. Page 18 of 23

19 6. Limitations and Outlook The following chapter will describe limitations of the conducted research and outline suggestions for further research. The limitations concern: 1. The authors of this paper did not conduct own empirical measurements and/or simulations. For this reason, knowledge about the reliability of the results and the data quality is limited. Considering the roughly 90 years of temporal scope most studies have, there is high potential for uncertainties. 2. The qualitative approach is strongly restricted because the information received by the approach is not based on any controlled empirical environment. It is only a textual response of the Itaipu Binacional company members. 3. All the results presented in this study are case study specific. Climate conditions vary extremely around the globe. The same can be mentioned for other framework conditions e.g. fiscal policies, like the capacity based financial structure of the dam. Other hydroelectricity dams might be affected in more threatening or favorable ways. Further research should: 1. Conduct a sophisticated qualitative study on the Itaipu dam s resilience to climate change i.e. visit the dam and conduct expert interviews with managers and engineers. 2. Conduct more spatially highly decomposed modelling studies similar to the one of Rivarola Sosa et al. (2011). It is highly recommended to create model ensembles for local areas, like done by Magrin et al. (2014) for continental areas. Page 19 of 23

20 Bibliography Blackshear et al. (2011): Hydropower Vulnerability and Climate Change A Framework for Modeling the Future of Global Hydroelectric Resources. Middlebury College Environmental Studies Senior SeminarFall Available online at checked on 4/3/2016. Britannica (2016): Enzyclopedia Guri-Dam. Available online at checked on 4/2/2016. EIA (2016): U.S. Energy Information Administration. International Energy Statistics. Available online at checked on 4/11/2016. Hamududu, Byman; Killingtveit, Aanund (2012): Assessing Climate Change Impacts on Global Hydropower. In Energies 5 (12), pp DOI: /en IPCC (2000): Emissions scenarios. Summary for policymakers ; a special report of IPCC Working Group III. Geneva: Intergovernmental Panel on Climate Change (IPCC special report). Itaipu binacional (2016g): Climatic Changes. Available online at ( checked on 4/5/2016. Itaipu binacional (2016b): Energy. Market Participation. Available online at checked on 4/2/2016. Itaipu binacional (2016c): Energy. Available online at checked on Itaipu binacional (2016a): History. Available online at checked on 4/2/2016. Itaipu binacional (2016e): Parana River. Available online at checked on 4/2/2016. Itaipu binacional (2016d): Reservoir. Available online at checked on 4/2/2016. Itaipu binacional (2016f): Value added statement Itaipu binacional. Available online at checked on 4/3/2016. Magrin, G.O., J.A. Marengo, J.-P. Boulanger, M.S. Buckeridge, E. Castellanos, G. Poveda, F.R. Scarano, and S. Vicuña (2014): Central and South America. In: Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part B: Regional Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp Mapfrappe (2016): Hydroelectric dams and reservoirs. Compare maps. Available online at checked on 4/11/2016. Mercosur (2007): The Itaipu dam. Location of the Itaipu dam. Available online at checked on 4/11/2016. Oswald and Vonsee (2016): Qualitative approach via to Itaipu binacional. Open questions applied. Rivarola Sosa, J. M.; Brandani, Giada; Dibari, Camilla; Moriondo, Marco; Ferrise, Roberto; Trombi, Giacomo; Bindi, Marco (2011): Climate change impact on the hydrological balance of the Itaipu Basin. In Met. Apps 18 (2), pp DOI: /met.213. Schaeffer, Roberto; Szklo, Alexandre Salem; Pereira de Lucena, André Frossard; Moreira Cesar Borba, Bruno Soares; Pupo Nogueira, Larissa Pinheiro; Fleming, Fernanda Pereira et al. (2012): Energy sector vulnerability to climate change. A review. In Energy 38 (1), pp DOI: /j.energy Schreier, Margrit (2012): Qualitative content analysis in practice. 1. publ. London u.a.: Sage Publ. van Vliet, Michelle T. H.; Wiberg, David; Leduc, Sylvain; Riahi, Keywan (2016): Power-generation system vulnerability and adaptation to changes in climate and water resources. In Nature Climate change 6 (4), pp DOI: /nclimate2903. Page 20 of 23

21 Wikipedia (2016): Kashiwazaki-Kariwa Nuclear Power Plant. Available online at checked on 4/11/2016. Page 21 of 23

22 Appendix Our approach to Itaipu Binacional Dear Ladies and Gentlemen, I write you with my German home data but we are two students of the Utrecht University in the Netherlands and we are writing a paper about the vulnerability of hydro power plants due to climate change and in particular about the Itaipu Dam. We wanted to ask you if you can give us any first hand expert-information about the expected influence on the energy/power generation of the Itaipu dam due to climate change. In the following I note down some specific questions we would be interested in. How much is precipitation going to change and going to influence the dam's generation patterns? Is it affecting the energy security in Brazil or Paraguay? Maybe climate change is causing positive/enhancing effects on energy security? Is it affecting the company's economic situation? We would be very grateful if you could come back to us :). In return we can offer you the finished paper. We are looking forward to your answer. Best regards from the Netherlands. Yannick Oswald and Bram Vonsee. Answer of Itaipu Binacional Dear Student Yannick, Below we send to you reply prepared by the Division of Hydrological and Energy Studies (OPSH.DT) and by the Division of Programming and Production Control (PCCP.TE). Dear Mr. Yannick, Thank you for your interest about Itaipu Binacional. Here are the answers to two of your questions: How much is precipitation going to change and going to influence the dam's generation patterns? South and south-east of Brazil are regions where the weather (and hence climate) predictability is not good an this is apparent on all efforts to generate climate scenarios for the region. Anyway, Itaipu is already operating in a situation of uncertainty, given the abrupt increase of inflow experienced by part of Paraná River basin in the '70s, changes probably caused by small changes in precipitation volume and pattern and changes in land use on the basin. Any change in the precipitation behavior in the basin will be dealt not by Itaipu itself but by the cascade of about 50 reservoirs we have upstream. Changes will be dealt by a coordinated operation of these reservoirs: dispatch in Brazil is centralized and done using probabilistic tools to deal with uncertainties of future inflows. For all these reasons and also because Itaipu, despite its size, it's a run of the river power plant, we do not expect our operation to change much, but we are aware of possible changes and we can adapt to the foreseeable possible inflow changes without any technical or economical problem. Page 22 of 23

23 Is it affecting the company's economic situation? No. Itaipu's economic situation is not affected by this kind of issue, given its financial engineering is based on selling the availability of the installed capacity of the plant, not the actual power production. Regarding to the other two questions about energy security, we would like to inform you that in Brazil, the analisis of energy security is entitled to federal bodies such as: - the Ministry of Mines and Energy - MME ( - the Energy Research Company - EPE ( and - the National Operator - ONS ( In Paraguay there is the Vice Ministry of Mines and Energy ( Best regards from Itaipu. CANAL FALE CONOSCO - ITAIPU BINACIONAL - BRASIL DIVISÃO DE IMAGEM INSTITUCIONAL - CSII.GB ASSESSORIA DE COMUNICAÇÃO SOCIAL - CS.GB CENTRO EXECUTIVO DA ITAIPU BINACIONAL Name change Name cover for privacy reasons Foz do Iguaçu, Paraná, Brasil Fone: (45) Page 23 of 23