Kirsten Dunlop Chief Executive Officer, Climate KIC Augusta Grand Chief Executive, Eden GeothermalAlexander Helling Co-Founder and Chief Executive Officer, Baseload Capital Angela Oduor Lungati Executive Director, Ushahidi In the clean energy landscape, geothermal energy offers a rare combination: constant output, minimal land use and the potential to scale globally. Despite its promise, geothermal supplies less than 1% of global electricity.66 Advances in modular, factory- built geothermal systems and improvements in drilling technologies are expanding where and how geothermal can be deployed. By displacing fossil fuels and reducing land disturbance, water use and pollution, modular geothermal systems support key planetary boundaries related to climate change, land-system change, freshwater use and atmospheric aerosol loading. Conventional geothermal depends on naturally occurring hydrothermal reservoirs and requires lengthy custom builds. Modular geothermal energy solutions refer to scalable, often prefabricated systems that harness the Earth’s heat for power generation or heating. Unlike traditional large geothermal plants tied to specific high-temperature reservoirs, modular systems do not require specific geological conditions and can be deployed in a variety of formats – from small power units on individual wells to containerized heat pump installations for buildings. They can deliver weather- independent heating, cooling and baseload electricity to residential homes, apartment blocks and offices, as well as manufacturing sites, and can be installed in diverse locations, often with small footprints, reducing construction time and complexity.67 A new generation of closed-loop systems involves sealed, underground pipe networks that circulate fluid to extract heat from surrounding rock, without tapping aquifers or releasing emissions into the environment.68,69 Breakthroughs in drilling technologies – drawing on methods developed in the oil and gas sector – are enabling the deployment of closed-loop systems. Key innovations include directional drilling to reach targeted depths, improved wellbore sealing to withstand high temperatures and thermal modelling to optimize performance. Combined, these advances are opening new markets for geothermal energy. In 2023, Fervo Energy demonstrated one of the first commercial- scale applications of enhanced closed-loop geothermal using horizontal drilling and fibre-optic sensing techniques adapted from the oil and gas industry. The pilot project in Nevada, US, produced 3.5 megawatts (MW) of round-the-clock electricity, validating the viability of closed-loop geothermal in previously inaccessible geologies.70 Building on this success, Google partnered with Fervo to supply clean power to its Nevada data centre – marking a milestone in applying modular geothermal systems to digital infrastructure.71 Modular geothermal isn’t limited to power generation and also includes ground-source heat pump systems for buildings and small-scale units that can be added or moved as needed. The technology is being piloted for district heating in Europe, backed by a €7.4 billion investment across Germany, France and the Netherlands to build low-carbon heating infrastructure.72 Ground-source heat pumps from companies like Vattenfall and Dandelion Energy tap into the moderate geothermal warmth just metres below ground and are an efficient replacement for oil or gas boilers in homes.73,74 As modular geothermal systems scale, they advance climate goals while benefitting industries, economies and communities. Environmentally, they reduce greenhouse gas emissions by displacing fossil fuels, and use far less land, water and materials than many other renewables, helping ease pressure on planetary boundaries related to land-system change, freshwater use and atmospheric aerosol loading. In industry, co-locating modular units with data centres, manufacturing plants or agricultural facilities can provide consistent energy, enable energy cogeneration and reduce reliance on volatile fuel markets. Transitioning to modular geothermal could support job creation in drilling, engineering, construction and maintenance – particularly in regions where existing fossil expertise and infrastructure can be redirected towards clean energy. Currently, however, upfront costs are high and permitting pathways remain unclear in many jurisdictions. Societally, modular geothermal could strengthen energy resilience in underserved communities by enabling locally managed power. This technology offers a rare opportunity to expand clean energy access without requiring an entirely new workforce, pipelines or infrastructure footprints – making it especially valuable in regions seeking just and practical energy transitions. Societally, modular geothermal could strengthen energy resilience in underserved communities by enabling locally managed power. 10 Emerging Technology Solutions for Planetary Health 29

10 Emerging Technology Solutions for Planetary Health 2025