Roughly 600 geothermal power plants operate across 30 countries in 2025, with a combined capacity of about 16 GW. Individual plants vary enormously in size, from single MW binary units to the 700 MW cluster at The Geysers in California. This guide covers the count, distribution, and how the fleet is growing.
Counting geothermal plants
Counting geothermal plants requires deciding what counts as a "plant". Options include: single generating unit, contiguous power block, or shared reservoir field. Different sources use different definitions. Under a moderate definition, roughly 600 plants operate globally. Under a strict single unit definition the number is closer to 800.
Distribution by country
| Country | Approximate plant count | Total MW |
|---|---|---|
| United States | ~180 | ~3,700 |
| Indonesia | ~50 | ~2,400 |
| Philippines | ~40 | ~1,900 |
| Turkey | ~60 | ~1,700 |
| Mexico | ~15 | ~1,000 |
| New Zealand | ~25 | ~1,000 |
| Kenya | ~10 | ~950 |
| Italy | ~30 | ~800 |
| Iceland | ~10 | ~750 |
| Japan | ~30 | ~600 |
| Rest of world | ~150 | ~1,200 |
The largest geothermal fields
Geothermal fields typically host multiple plants sharing the same reservoir.
- The Geysers, California. ~700 MW across ~18 plants. Largest single field globally.
- Cerro Prieto, Mexico. ~700 MW.
- Sarulla, Indonesia. ~330 MW.
- Larderello, Italy. ~800 MW cumulative across the historical field.
- Olkaria, Kenya. ~800 MW.
Plant size distribution
| Size band | Approx count globally |
|---|---|
| Under 10 MW | ~250 |
| 10 to 30 MW | ~200 |
| 30 to 100 MW | ~100 |
| Over 100 MW | ~50 |
Growth rate
Geothermal has grown modestly for the past decade, at 2 to 3 percent annually. This is expected to accelerate with EGS commercialisation. See our companion article on geothermal energy explained.
Plant types by count
Binary cycle plants dominate the count because they suit lower temperature resources. Flash steam plants have larger unit sizes. Dry steam plants are rare and concentrated at Larderello and The Geysers.
New plants coming online
Recent additions include projects in Turkey, Indonesia, Kenya, Chile, and Croatia. The IEA Renewables 2024 tracks the pipeline. Ethiopia has multi hundred MW projects planned. US EGS pilots are adding new plant types.
EGS plants entering the count
Enhanced geothermal systems (EGS) plants are beginning to appear in the fleet. Fervo Energy has commissioned a 3.5 MW pilot in Nevada and started construction on a larger commercial project in Utah. Eavor is developing closed loop projects in Alberta and Germany. If EGS reaches commercial scale in the late 2020s, plant count could grow substantially.
Data sources for the count
The International Geothermal Association maintains country level statistics. National regulators publish specific plant data. The UtilityRadar directory covers global plants including geothermal.
Notable individual plants
| Plant | Country | MW |
|---|---|---|
| Nesjavellir | Iceland | 120 |
| Hellisheidi | Iceland | 303 |
| Wayang Windu | Indonesia | 227 |
| Malitbog | Philippines | 230 |
| Sarulla | Indonesia | 330 |
| Cerro Prieto complex | Mexico | 720 |
| Larderello (multiple) | Italy | 800+ |
Direct use plants
Beyond power plants, thousands of direct use geothermal installations exist globally (district heating, greenhouse warming, aquaculture). These are typically not counted as "geothermal power plants" but represent significant additional geothermal utilisation.
Global picture
Where the count is going
The IEA net zero scenario projects the fleet to grow 3 to 5x by 2050 with EGS providing much of the growth. Existing geothermal countries will continue expansion, and new countries (Ethiopia, Chile, Croatia, US EGS) will add to the count.
Frequently asked questions
How many countries have geothermal?
About 30 countries operate commercial geothermal power plants.
Which is the largest single plant?
The Malitbog plant in the Philippines at 230 MW is often cited. The Geysers is a cluster of plants exceeding that at field level.
How is a plant counted?
Definitions vary. Contiguous power blocks are most common definition.
Are there small geothermal plants?
Yes, many. Small binary plants of 3 to 10 MW are common.
Does the count include exploration wells?
No. Only operational plants.
Which country adds most plants annually?
Recent years: Turkey and Indonesia lead by count. US is scaling EGS pilots.
Are there floating or offshore geothermal plants?
No commercial ones yet. Some concepts in development.
How long do geothermal plants last?
25 to 40 years typical, with refurbishment. Larderello has generated for over 100 years.
Are there decommissioned plants?
Yes, primarily older or exhausted reservoir fields. Small numbers.
Where can I see plant data?
UtilityRadar directory, IGA statistics, national regulators.
Summary
Roughly 600 geothermal power plants operate globally with a total capacity of about 16 GW. The US leads count, Indonesia leads potential, Kenya leads share of national grid. The fleet is growing modestly, with EGS pilots pointing to potential faster growth in the coming decade. For anyone tracking the sector, the pipeline in Turkey, Indonesia, Kenya, Ethiopia, and US EGS pilots is the near term growth story.
Next reading
- Geothermal energy explained
- Geothermal countries lead
- Renewable energy complete guide
- Browse the UtilityRadar directory
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