Seite - 27 - in options, Band summer 2018

interviewpeople at iiasa 27www.iiasa.ac.at summer 2018 ◼ options Julian Hunt is a postdoc research scholar at IIASA where he works with the Energy and Water programs in collaboration with the CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Education Ministry) Brazilian Foundation for support researchers. His research interests include analysis of energy systems, water-energy-land interfaces, climate change risks, and energy security. Seasonal pumped-storage – the answer to water and energy security? Q&A with Brazilian IIASA postdoc Julian Hunt Q What is seasonal pumped-storage? A Pumped-storage is a form of hydropower used for storing energy to guarantee that electricity supply meets demand, especially during peak hours. It is normally used in daily cycles to store energy from inflexible power plants– such as coal and nuclear–at night, and to generate power during the day. The future of this type of short-term storage is uncertain as batteries become more efficient and less expensive. Seasonal pumped-storage (SPS) on the other hand can be used for the short, medium, and long-term storage of intermittent renewable sources of energy like wind and solar that have hourly, daily, weekly, and seasonal variations. Q What exactly do you research? A I published a paper comparing SPS with conventional dams. The main finding is that SPS requires considerably less land to store energy and water. This is because the reservoir level can vary markedly more than in conventional dams. It also involves fewer social and environmental impacts as the reservoirs are built in mountain ranges rather than in the main river. Seasonal pumped-storage (SPS) on the other hand can be used for the short, medium, and long-term storage of intermittent renewable sources of energy like wind and solar that have hourly, daily, weekly, and seasonal variations. Q How did you get interested in such plants? A During my D.Phil. at Oxford, I developed a decision support system to find the best alternatives for energy in the UK looking at a water perspective. I found that wind power is a good solution, but it requires storage. I looked at possible sites for large-scale pumped-storage plants in Scotland and found that if the deep lochs were used as a lower reservoir, and surrounding mountains as upper reservoirs, they could store huge amounts of energy and make wind power a viable solution. During my postdoctoral research in Brazil, I thought of combining large-scale pumped-storage plants with the operation of the existing hydropower plants. It proved to be a very good combination that I later named seasonal pumped-storage. Q Why is seasonal pumped-storage important to Brazil? A Most electricity in Brazil is generated by hydropower and the country suffers an energy crisis every 10 to 15 years due to countrywide droughts. SPS is a possible solution for this issue. During years with abundant hydropower generation, some of the wasted hydropower potential can be stored and then used in dry years to guarantee the supply of electricity. HT Julian Hunt hunt@iiasa.ac.at