Project InnerSpace, a nonprofit, focused research organization committed to the exponential global growth of geothermal energy, and the Society of Petroleum Engineers (SPE), the world’s largest nonprofit member organization for oil and gas professionals, today announced that the Geothermal Resources Management System (GRMS), a standardized framework for classifying, reporting, and communicating geothermal resources and reserves first announced in March 2026, has completed its technical drafting and industry working-group consensus process and has been approved by the SPE Board of Directors for publication.
Modeled on the petroleum industry's foundational Petroleum Resources Management System (PRMS) and the CO2 Storage Resources Management System (SRMS) standards that have enabled trillions of dollars in oil and gas investment over the past century, GRMS gives geothermal projects a resource and reserves classification system that financial institutions, insurers, and regulators already know how to use. With SPE Board approval secured, GRMS is expected to publish online in November 2026.
"For 40 years, PRMS has been the language that flowed trillions into oil and gas development. We are excited to have built a structure through the GRMS coalition that will do the same for geothermal today," said Jamie Beard, founder and executive director of Project InnerSpace.
“Standards play a critical role in enabling investment, transparency, and industry growth. The SPE Board's approval of GRMS signals confidence in both the technical integrity of the framework and the broad industry consensus behind it. We believe GRMS will become an essential tool for bringing greater consistency and clarity to the assessment and reporting of geothermal resources around the world,” said Simon Seaton, CEO of SPE.
Over the past 6 months, Project InnerSpace and SPE led a cross-industry effort that convened a multidisciplinary coalition of volunteers and authors spanning reserves evaluators, oil and gas operators, insurers and underwriters, private equity firms, and geothermal developers to develop the GRMS framework. GRMS will be published on the SPE OnePetro site with no membership requirement or paywall to access it. Open access was made possible through Project InnerSpace's financial support of the publication process, removing cost as a barrier to adoption and allowing any reserves evaluator, lender, insurer, regulator, or operator anywhere in the world to access and apply the standard out of the gate.
With the framework approved by the SPE Board, Project InnerSpace and SPE are turning to the work of naturalizing GRMS into everyday geothermal financing practice, training reserves evaluators, lenders, insurers, regulators, and geothermal and oil and gas operators to apply the system consistently across deals, filings, and underwriting. Phase II of the collaboration, scheduled for early 2027, will develop practitioner application guidelines, including case studies across a variety of geothermal technology types, and continue socialization of the standard with financial institutions through convenings and workshops.
About Project InnerSpace
Project InnerSpace is the leading independent nonprofit organization dedicated to the global development of geothermal energy. We are a focused research organization on a mission to remove the major barriers standing in the way of the exponential growth and development of geothermal energy worldwide by 2030. To learn more about Project InnerSpace, visit www.projectinnerspace.org.
About the Society of Petroleum Engineers
SPE is a not-for-profit professional association with more than 129,900 members in 148 countries engaged in the exploration and production of oil and gas and related energy resources. SPE delivers solutions and empowers people to drive the energy industry forward. Members gain access to premier programs, content, and events designed to accelerate professional growth and career development, while fostering a strong network and sense of community. SPE maintains offices in Calgary, Dallas, Dubai, Houston, and Kuala Lumpur. To learn more about SPE, visit https://www.spe.org.