Energy Systems and Technologies for the Coming Century ...

northern South America, the Caribbean and parts of southern Asia (Ebinger and Vergara,2011). Another trend is a substantial increase in heavy precipitation events in manyregions, even in areas that have experienced a decrease in overall precipitation.To assess climate change impacts on hydropower, long-term changes in climatevariables are translated into run-off (Su and Xie, 2003; Madani and Lund, 2010; Singh,Thompson et al., 2010). The areas most affected include mountainous areas, valleys andrivers fed by melting snow and ice, where run-off and early spring discharge haveincreased (Dussaillant, Benito et al., 2010). However, as glaciers and snow melt andprecipitation patterns change, run-off is likely to decrease. These impacts severely affectthe availability of hydropower resources at regional and local levels. The warming oflakes and rivers affect the thermal structure and water quality (Delpla, Baures et al.,2011). An indirect impact is increased competition for water among economic sectorssuch as agriculture, energy and recreation.The supply of electricity from hydropower depends partly on the variation in water flowsand partly on installed generation capacity. Most systems are designed based onhistorical records assuming a stable climate, but increasingly analysis try to modelprojected changes in hydropower generation (Kim and Kaluarachchi, 2009). Two factorsare particularly important for the vulnerability of hydropower to climate change impacts:1) The share of hydropower in the energy mix of the system, and 2) Integration oftransmission networks nationally and regionally, as this decides whether plants should beoptimized individually or in the context of a larger energy system. Small run-of-riverplants offer little flexibility, but are at the same time associated with much lowerinvestment costs, whereas reservoir storage capacity can compensate for seasonal – evenannual – variations in water flows (Raje and Mujumdar, 2010).Peer reviewed literature is larger in volume and available for more regions of the worldfor hydropower than for wind power, although developing country analysis is underrepresented(Mideksa and Kallbekken, 2010)5. A study by Harrison et al. (2003)analyses the impacts of climate change on financial risk in hydropower projects using theZambezi river basin as a case. They find that climate change has the potential to bedoubly damaging for hydropower with the alteration of both the expected return fromhydroelectric installations and the financial risk that they face. Large parts of Africa relyheavily on hydropower for electricity production and recent droughts have hadsignificant impacts on power supply and economies (Eberhard et al., 2008; Karakezi etal., 2009). Further analyses of financial risk implications would be valuable both forAfrica and generally.In relation to liquid biofuels, the crops used as raw material to produce ethanol andbiodiesel such as sugarcane, soybeans and maize are vulnerable to the effects of climatechange. Climate change affects temperature, precipitation patterns, extreme weatherevents (droughts, floods, storms, fires and frost) and the level of CO 2 affecting the rate ofphotosynthesis, which all have significant impacts on crops (Dhakhwa, Campbell et al.,5 Studies include detailed analyses of impacts caused by the anticipated consequences of climatechange on Peru’s hydrology and hydropower potential (World Bank 2010c; World Bank, 2010d);hydropower generation vulnerability to climate change and water management practices in Brazil(Freitas and Soito, 2009); linkages between energy, poverty and climate change in Latin Americaand the Caribbean (Bariloche Foundation, 2009); analysis of climate change implications onhydropower in the Nordic region (Beldring et al. 2006; Fenger, 2007); evaluation of the impacts onhydropower, power plant efficiency, unproductive spills and reservoir reliability due to changes inthe hydrological regimes for the Peribonka River water resource system in Quebec (Minville et al.,2009); analysis of the impacts of projected climate change on two Aegean water basins and relatedissue of water stress for competing uses (Ozkul, 2009); large scale distributed hydrologicalmodelling to study the impact of climate change on the water flows of the mountainous Upper-Danube watershed in Central Europe (Mauser and Bach, 2009); impacts on hydropower productionbased on the Colorado River (Barnett et al., 2004) and the Central Valley (van Rheenen et al., 2003)in the United States.Risø International Energy Conference 2011 Proceedings Page 29