SUSTAINABILITY, SUPERSTITION, AND SAGANAKI: OVERCOMING OBSTACLES FOR DEVELOPMENT OF GEOTHERMAL ENERGY ON THE VOLCANIC ISLAND OF NISYROS, GREECE

In the late 1990s, thanks to Drs. Jelle Z. De Boer and Joop Varekamp, an aspiring undergraduate was given the opportunity to travel to Nisyros and Santorini, two beautiful volcanoes of the Aegean volcanic arc. She sampled volcanic rocks to characterize differences in trace element and isotopic signatures. During a power outage one night at the taverna, she heard of proposals to construct a geothermal power plant on the island, which, to this day, depends on a submarine cable carrying fossil-fuel derived electricity from neighboring Kos island. Two distinct hydrothermal aquifers are present beneath the caldera floor (Lakki plain) in Nisyros, a deep aquifer at >300°C, and a shallow aquifer (250-700 m deep) discharging steam and gas through fumaroles at ~100°C. Additional assessments have shown geothermal fluids up to 350°C, which have the potential to generate 50MW, far more than the island of Nisyros needs.

Local resistance to these geothermal proposals has been aplenty. Two test wells drilled on the Lakki Plain in the 1980’s failed due to overheating and overpressure. To complicate things, the god of the volcano, Polyvotis, was known to be easily excited, and increased earthquake activity (1996-1998) was blamed on his fury. Residents were concerned about pollution from the project destroying their already stressed fisheries. An environmental impact assessment from 1991 concluded that a proposed 10MW geothermal power station would have “no significant adverse effect on the environment and should have small but significant beneficial effects.”

So more than 20 years later, what has changed? The pressure to ensure energy independence and find alternatives to fossil fuels has grown. In 2021, the mayor of Nisyros is a professor in sustainability, who has published analyses showing the promise of clean energy production. Is Nisyros on the brink of becoming self-sufficient, or even an energy exporter to the neighboring Dodecanese Islands? We review advances in geothermal energy production, and explore a range of possible development strategies weighing the technical, environmental, social, and economic tradeoffs. This presentation ties together the tectonics and mythology of the Aegean, which Jelle loved so much, with the real-world issues related to harnessing the power of the volcano in the 21^st century.