Two of the four existing ORC units will be replaced with Exergy’s ORC system, based on a single-pressure-level cycle, to produce clean electricity using its radial outflow turbine technology.
Exergy International was awarded a €24.5 million contract by EDA Renováveis (EDAR) for a comprehensive upgrade of the Ribeira Grande geothermal power plant, located on the island of São Miguel in the Azores, including the engineering, manufacturing, construction, and commissioning of a new 5 MWe geothermal binary power unit. As part of the modernization effort, two of the existing 2.5 MWe organic Rankine cycle (ORC) systems—originally installed in 1994—will be decommissioned and replaced with a 5.3 MWe unit. Exergy’s ORC system, based on a single-pressure-level cycle, is optimized to extract energy from a geothermal resource at around 150°C, utilizing both steam and brine phases.
“We are honored to renew our collaboration with EDA Renováveis through this important project,” said Luca Pozzoni, Deputy CEO of Exergy International. “This revamp not only reaffirms the long-term value of our Radial Outflow Turbine technology but also demonstrates our ability to deliver high-efficiency systems under challenging timelines and technical conditions.”
Exergy’s radial outflow turbine, with high isentropic efficiency, is central to the system’s ability to generate an estimated 5.3 MWe, surpassing the contracted output requirement and significantly improving plant performance.
“The Ribeira Grande repowering marks a critical milestone in our plan to scale renewable energy on São Miguel,” said António Félix Rodrigues, Managing Director of EDA Renováveis. “In 2024, nearly 89% of electricity injected into the Azorean grid came from renewable or indigenous sources. This project, along with the expansion at Pico Vermelho, brings us closer to reaching 60% renewable electricity on the island by 2026.”
The plant will be equipped with an air-cooled condenser to avoid water consumption and ensure minimal environmental impact. All geothermal fluids will be fully reinjected, supporting sustainable resource management and long-term operational integrity.
Exergy will execute the project under a full engineering, procurement, and construction framework, which includes the gathering system. The First Provisional Take-Over is scheduled for June 2026, with final commissioning planned by the end of the year.
This is the second major contract awarded by EDAR to Exergy, following the successful delivery of the 4 MWe Pico Alto plant on Terceira Island in 2017. The new Ribeira Grande unit further solidifies the partnership and underscores Exergy’s leadership in geothermal energy solutions, especially in complex volcanic regions.
The Ribeira Grande upgrade is part of a broader initiative by the Azorean government to expand geothermal energy as a cornerstone of the region’s clean energy mix. With current geothermal operations limited to São Miguel and Terceira, the islands already source over 21% of their electricity from geothermal resources. The long-term target for the region is to exceed 70% renewable generation and achieve full carbon neutrality by 2050.
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