Paper short abstract:

The paper examines the role of oil companies and technologies in the development of geothermal energy. As will be argued, the "spillover" of oil technologies was crucial for worldwide geothermal development from the 1960s, revealing an understudied link and the messiness of historical transitions.

Paper long abstract:

Between the 1960s and 1980s, the geothermal energy resources of several of the world’s most volcanically active regions were developed at scale. This development surge was enabled by improved exploration and drilling methods, along with decisions to invest in geothermal energy as an environmentally friendly and renewable alternative to fossil fuels. An often overlooked but crucial factor in the history of geothermal development were “spillovers” from the oil industry. While fundamentally different in end use, geothermal and hydrocarbon industries employ similar methods for exploring and extracting fluids and gases. Adapted to the requirements of geothermal energy, petroleum technologies – ranging from geoscientific exploration techniques, oilwell rotary drilling rigs, to well-logging and reservoir engineering – greatly improved the knowledge of geothermal reservoirs, the success rate of well drilling and the efficiency of geothermal energy production. In this paper, I analyze spillovers between oil and geothermal industries in the cases of Italy, California, New Zealand, Indonesia and Iceland, which all developed large geothermal fields with the help of petroleum technologies. Those oil spillovers ranged from the direct involvement of oil companies in geothermal projects – above all Union Oil, ENI and Chevron – to rather indirect influences with the exchange of geoscientists, independent drilling companies and research institutes between the industries. As I will argue, energy history needs to pay more attention to the co-evolution of multiple energy systems and the messiness of transition processes, as oil actors and companies played a key role in the transition processes to geothermal energy.