Almost every hot shower taken in Reykjavík is heated by water pulled directly from the ground. Not warmed by burning gas, not run through an electric boiler — just geothermal water, piped from wells drilled into volcanic rock, arriving at your tap having already done most of the work underground. Iceland geothermal energy is not a novelty or a green marketing angle. It is simply how this country functions, and has for most of the twentieth century.
Understanding how it actually works changes how you see the country. Those clouds of steam rising from hillsides near Hveragerði? Active vents feeding into a system that heats tens of thousands of homes. The faint sulphur smell in the hot water? That is not a fault — it is geology doing its job. Once you know what you are looking at, Iceland starts to make a different kind of sense.
Why Iceland Has Geothermal Energy at All
Iceland sits directly on the Mid-Atlantic Ridge, the boundary where the North American and Eurasian tectonic plates are slowly pulling apart — about 2.5 centimetres per year. That sounds small, but the result is a country riddled with volcanic systems, magma chambers close to the surface, and groundwater that gets heated to extraordinary temperatures without anyone needing to do anything about it.
There are around 200 volcanoes in Iceland, and roughly 30 of them are active. The heat those systems generate doesn’t just produce eruptions — it percolates through the rock constantly, warming water tables and creating natural hot springs across the entire country. The Reykjanes Peninsula, the highlands around Landmannalaugar, the area around Mývatn in the north — all of them are geothermally active, and all of them feed into different parts of the national energy system.
This is not something Iceland engineered. It is something Iceland inherited and, over decades, learned to use extremely well.
How Iceland Geothermal Systems Actually Work
The basic principle is simpler than most people expect. Rainwater and snowmelt seep down through porous rock. Deep underground, that water contacts rock heated by magma. The water heats up — sometimes to well above 100°C — and then rises back toward the surface through natural pressure, or gets pulled up through drilled wells.
From those wells, the story splits into two main uses: direct heating and electricity generation. They are related but technically distinct, and Iceland does both at significant scale.
District Heating: The System Under Reykjavík
Reykjavík’s district heating network is one of the most extensive in the world. Geothermal water is extracted from wells, many of them located at the Nesjavellir and Hellisheiði power stations on the volcanic plateau southeast of the city, and then piped tens of kilometres into the capital and surrounding municipalities. The water arrives at temperatures around 80–85°C, which is exactly what you need for space heating and domestic hot water.
Veita Orkuveita Reykjavíkur — Reykjavík Energy — manages this network. They supply hot water to around 220,000 people across the greater capital area. Walk into almost any building in Reykjavík, and the radiators are running on water that came out of the ground somewhere in the lava fields south of the city.
One detail that surprises most visitors: the hot tap water in Reykjavík smells faintly of sulphur. This is normal. The cold water comes from groundwater reserves filtered through lava (it is exceptionally clean), but the hot water carries a geological signature. You get used to it quickly. Most Icelanders barely notice it anymore.
Electricity from Steam: How the Turbines Work
Higher-temperature geothermal resources — water and steam above 150°C — get used to generate electricity. The process works like this: high-pressure steam is separated from the geothermal fluid and used to spin turbines, which drive generators. The water that doesn’t flash into steam gets re-injected into the ground to maintain reservoir pressure and reduce environmental impact.
Iceland’s largest geothermal power stations include Hellisheiði (303 MW of electricity, 133 MW of thermal capacity), Nesjavellir (120 MW electrical), and Reykjanes (100 MW electrical) on the peninsula of the same name. Together with hydroelectric plants — which handle the other major chunk of Iceland’s electricity supply — these stations mean Iceland runs almost entirely on renewable energy. Fossil fuels account for a negligible percentage of electricity and heating nationwide.
That is not an aspiration. That is the current reality, and it has been for decades.
Where You Can Actually See It Working
Knowing the theory is one thing. Seeing the infrastructure in person is something else, and Iceland makes it relatively easy to do both.
Hellisheiði Power Station and the ON Power Exhibition
Hellisheiði is located on the Reykjanes Peninsula, about 20 km southeast of Reykjavík on Route 1, and it is the most visitor-accessible major geothermal station in the country. The on-site exhibition — run by ON Power, the energy company — walks you through how the plant works, what geothermal energy actually is, and what Iceland is doing to capture and store CO₂ emissions from the plant itself (a project called CarbFix, which is genuinely remarkable).
Entry costs around 2,500 ISK (approximately €17 / $18). It is not the most thrilling museum you will ever visit, but if you have any interest in how Iceland’s energy system functions, it answers the questions clearly and with real equipment visible through the windows. The drive out there is easy, and it pairs naturally with a stop at the geothermal pools at Hveragerði, about 15 km further east on the same road.
Hverir and the Mývatn Area
In the north, near Lake Mývatn, the Hverir geothermal field near Námaskarð pass is one of the most visually dramatic geothermal sites in Iceland — boiling mud pools, fumaroles venting steam, ground coloured yellow and orange with sulphur deposits. It costs nothing to visit and sits right off Route 1, about 490 km from Reykjavík.
The Mývatn Nature Baths (Jarðböðin við Mývatn) nearby are heated entirely by geothermal water drawn from a borehole at 130°C, then cooled to a comfortable bathing temperature. Entry is around 6,500 ISK (approximately €44 / $47). It is significantly less crowded than the Blue Lagoon and, in my opinion, more interesting — partly because the landscape around it feels wilder.
The Blue Lagoon: Geothermal as Experience Economy
The Blue Lagoon near Grindavík on the Reykjanes Peninsula is the most famous geothermal attraction in Iceland, and it is worth being honest about what it is. The milky blue water is not a natural hot spring. It is the runoff water from the Svartsengi geothermal power plant — seawater that was used in the energy process, discharged into a lava field, and then turned into a spa. The silica and minerals in the water are real, and the bathing experience is genuinely pleasant, but it was not always a natural place to swim.
Prices range from around 14,990 ISK (approximately €100 / $108) for the basic Comfort entry up to significantly more for premium packages. It is popular for good reasons, but if you want to understand Iceland geothermal energy itself, Hellisheiði or the Mývatn area will teach you more.
What This Means for Iceland’s Economy and Environment
Iceland’s energy costs are low by European standards, and geothermal is a big part of why. Heating a home in Reykjavík costs a fraction of what it would cost to heat the same building in Germany or the UK using gas. This has shaped everything from how buildings are designed (less insulation was historically installed, because heating was so cheap — something that is now being reconsidered) to which industries Iceland has attracted.
Aluminium smelting accounts for roughly 70% of Iceland’s industrial electricity consumption, largely because the country can offer power at rates that make energy-intensive industries economically viable. The Straumsvík smelter near Hafnarfjörður and the ÍSAL smelter at Straumsvík are the most visible examples. This is a complicated story — there are real environmental debates about whether cheap renewable energy should be used to smelt aluminium for global markets, or kept for different purposes — but it illustrates how central the energy system is to the economy.
On the environmental side, geothermal is not entirely without impact. Drilling can cause small earthquakes (microseismicity is routinely monitored near major plants). Steam and gases, including hydrogen sulphide and CO₂, are released during energy production. The CarbFix project at Hellisheiði is actively working to re-inject CO₂ back into the basalt rock underground, where it mineralises and becomes stone within two years. It is one of the more promising carbon capture approaches being tested anywhere in the world.
The Everyday Experience of Living with Geothermal
Living in Reykjavík, you stop thinking about the energy system consciously within about a week. The hot water is always hot — reliably, instantly. In winter, when temperatures drop well below freezing, the sidewalks in parts of the city centre stay clear because geothermal water runs through pipes underneath them. The outdoor public pools — Laugardalslaug, Vesturbæjarlaug, Sundhöllin, and more — are heated year-round and used year-round, which is why swimming culture in Iceland is genuinely different from anywhere else I have lived.
The pools, in particular, are the most direct way most visitors experience geothermal energy without thinking of it as an attraction. A swim at Laugardalslaug on a January evening, sitting in a hot pot at 42°C while snow falls, is not something you do because it is geothermal — you do it because it is exactly what you want to do. The fact that the whole thing is powered by water heated by the earth is just the backstory.
Entry to Reykjavík’s public pools costs around 1,200 ISK (approximately €8 / $9) for adults. They open early — most by 6:30am on weekdays — and they are where locals actually go, not just tourists. Worth the visit for that reason alone.
What’s Changing in Iceland’s Geothermal Future
There is active development happening on what is called Enhanced Geothermal Systems — essentially, drilling deeper into extremely hot rock to access heat that does not naturally produce steam or water. The Iceland Deep Drilling Project (IDDP) has been exploring temperatures of 400–600°C at depth, which would produce supercritical water with energy potential far beyond conventional geothermal. If this becomes commercially viable, it could multiply the usable resource enormously.
Iceland is also exporting knowledge. Geothermal consultancies based in Reykjavík work in Kenya, Ethiopia, Indonesia, and Central America, helping countries with similar volcanic geology develop their own systems. The expertise built here over the last eighty years has genuine global value, particularly as the world looks for ways to decarbonise heating — arguably the harder problem compared to electricity.
If you want to understand this side of things further, the annual Geothermal Energy Conference held in Reykjavík draws specialists from around the world and occasionally has public events worth attending. And if you are planning to visit the Reykjanes Peninsula — which the Golden Circle route does not cover, so it is often skipped — the combination of Hellisheiði, the Blue Lagoon, and the raw volcanic landscape around Reykjanesviti gives you a version of Iceland that is less about waterfalls and more about the actual forces shaping the place.
