Investors rarely reject geothermal because they doubt the resource. They reject it because they doubt the timeline.
A utility-scale solar farm can move from planning to operation in a matter of years. A geothermal project can spend years in exploration before producing a single megawatt. Wells must be drilled. Reservoirs must be tested. Infrastructure must be built long before revenue begins to flow.
That reality makes geothermal one of the most expensive renewable energy investments to start. It also makes it one of the hardest to replace once it succeeds. The real question is not whether geothermal is expensive. The real question is whether the long-term return justifies the patience.
A geothermal project demands enormous upfront capital. Exploration, drilling and power plant construction account for most of the investment before electricity is ever sold. That is why geothermal attracts governments, development banks and institutional investors far more often than short-term private capital.
Viewed only through initial construction costs, geothermal appears less attractive than solar or wind. Viewed over forty or fifty years of continuous operation, the calculation changes completely. Unlike intermittent renewables, geothermal plants are designed to operate almost continuously.
According to the latest global data from the International Renewable Energy Agency (IRENA), newly commissioned geothermal plants achieved an average capacity factor of 88% in 2024, among the highest of any renewable energy technology.
That single statistic explains why many investors continue backing geothermal despite the high entry cost. The plant keeps producing. Day after day. Year after year.
The Investment Is in Reliability
Electricity has one unforgiving rule. Supply must match demand every second. Solar disappears every evening. Wind slows when weather changes. Geothermal keeps operating because the Earth’s heat does not depend on daylight or seasonal weather.
That reliability gives geothermal a strategic value that extends beyond the price of electricity. It stabilises national grids, reduces dependence on imported fossil fuels and complements large deployments of wind and solar. For countries pursuing energy security, those benefits carry economic value that traditional cost comparisons often fail to capture.
The biggest financial risk is proving the resource. A developer may spend millions drilling exploration wells only to discover that the reservoir cannot support commercial electricity generation. Even successful projects often require years of geological studies, environmental assessments and production drilling before construction begins.
This explains why geothermal development progresses slowly. It is an industry where uncertainty is purchased before certainty is earned.
The Economics Improve Over Time
One criticism of geothermal is that its electricity costs have not fallen as dramatically as solar or wind over the past decade. That observation is accurate.
IRENA reports that geothermal’s global weighted average levelised cost of electricity has remained relatively stable, around US$0.05–0.07 per kilowatt-hour, while solar and wind experienced much steeper cost declines.
Yet focusing only on price ignores something equally important. Geothermal generates electricity when markets need it most. There is no requirement for large-scale battery storage to bridge overnight generation gaps, and utilities do not need to wait for favourable weather conditions before dispatching power.
- Reliability has economic value.
- Grid stability has economic value.
- Predictable generation has economic value.
Those advantages rarely appear in headline cost comparisons.
Technology Is Changing the Equation
The geothermal industry is entering a different phase. Advances in horizontal drilling, reservoir imaging and technologies adapted from the oil and gas sector are reducing exploration risk and expanding geothermal development beyond traditional volcanic regions.
The International Energy Agency estimates that continued technological progress could make geothermal a major contributor to global electricity growth by 2050, with investment potentially reaching trillions of dollars over the coming decades.
That projection is built on one assumption. Drilling becomes faster. Cheaper. More predictable. If that happens, geothermal’s biggest weakness begins to disappear.
So, Is It Worth the Investment?
For investors seeking quick returns, geothermal is a difficult proposition.
- Capital is committed early.
- Development timelines are long.
- Geological uncertainty remains unavoidable.
For governments planning energy systems that must operate for generations, the calculation is very different. A successful geothermal field delivers dependable electricity around the clock, strengthens energy independence and continues producing long after many other infrastructure investments have reached the end of their useful lives.
The value of geothermal has never been measured by how quickly it pays back. It is measured by how long it keeps paying.
