The continuous decay of radioactive elements regenerates geothermal energy reserves

Geothermal power can generate electricity and provide direct heating for homes

By drilling several kilometers through penetrable rock, wells can access highly pressurized groundwater warmed by thermal energy trapped beneath Earth's surface. This water can be turned into steam to create electricity in generators. Heating systems several meters deep can pump fluid underground before circulating it through buildings.

Fracking technology can help make geothermal power possible almost everywhere

Generating electricity from Earth's thermal energy has previously required existing underground reservoirs of hot water and permeable rocks through which the fluid naturally escapes. Today, fractures can be artificially created to form fluid pathways, and surface water can be injected underground and brought back to the surface.

Geothermal power can reduce the dangerous mining of rare earth elements

Geothermal brines—mineral-rich underground fluids extracted for use in geothermal plants—contain small concentrations of REEs that can be recovered after energy generation. Although researchers suggest that this retrieval requires complex extraction methods at a significant scale to account for high flow rates, the chemical processes also occur in traditional REE processing.

Geothermal power plants can provide large-scale energy storage for other systems

These facilities can store excess energy from solar and wind power as hot water or steam, which can be used to run turbines to generate electricity when other renewable energy sources are unavailable. Simulations have found efficiencies of 90% during a storage-use cycle, making it comparable to lithium-ion batteries.

As of 2022, just 0.5% of installed renewable energy capacity worldwide is geothermal

Despite being able to generate electricity regardless of the weather, solar (28%) and wind (27%) are far more prevalent, primarily because of their lower upfront costs. Geothermal plants use 88% less space than solar farms to produce the same energy, but have been restricted to geologically active regions.

Geothermal power can be used beyond heating and energy production

Depending on the depth of the natural vents or artificial wells drilled, the surrounding fluid temperature will vary greatly—from 10 to 371 degrees Celsius (50 to 700 degrees Fahrenheit)—allowing for various applications, including the drying of cement, concrete, and lumber, as well as the processing of pulp and paper.

Heat slowly moves through Earth's mantle like softened wax

Energy trapped during Earth's formation and released via the radioactivity of elements is carried by convection currents towards the surface, while cooler, denser material sinks. The planet's core is almost as hot as the sun's surface.

Explore next-generation geothermal projects worldwide

This tool from the Clean Air Task Force allows users to see the location of geothermal power systems to depths of 12.5 kilometers (7.8 miles), where temperatures reach about 450 degrees Celsius (842 degrees Fahrenheit), including proposed, abandoned, and in-development projects.

Like nuclear power, US geothermal power plant construction stalled for decades

Development and investment into geothermal energy took off in the 1960s. However, by the 1980s, companies repeatedly failed to find reservoirs of hot water when exploring new locations, and investors lost interest in the expensive drilling required. By the 2020s, technological advancements had finally helped mitigate exploration risk and expand viable drilling locations.

Geothermal power may meet 15% of global electricity demand growth through 2050

According to the International Energy Agency, the estimate would require the construction of geothermal capacity with an annual output equivalent to the combined electricity consumption in the US and India in 2024. The report suggests geothermal investment will reach $2.5T by 2050, with the integration of fracking technologies decreasing costs by 80% by 2035.

Among renewable sources, geothermal rivals hydropower in lifetime cost

As of 2024, the levelized cost of energy—the average cost per unit of energy over the lifetime of a power plant—for geothermal power is surpassed only by solar photovoltaic and onshore wind. Geothermal's LCOE has remained relatively unchanged since 2007, with significant decreases held back by significant upfront installation costs.

Enhanced geothermal power systems can trigger earthquakes by injecting fluid into rock, increasing subterranean pressure.

Wastewater from geothermal power plants helps melt sidewalk snow in Iceland

Located on the Mid-Atlantic ridge, where the North American and Eurasian tectonic plates move apart, the nation saw geothermal power meet more than 90% of its heating demand in 2024. After the hot water produced by these plants is used to heat homes and businesses, it is transferred through small pipes beneath Reykjavík's sidewalks.

Helium formation, from radioactive decay inside Earth to nuclear fusion within stellar cores

Over the course of billions of years, uranium and thorium undergo alpha decay, producing helium nuclei—two protons and two neutrons—which become helium atoms after gaining two electrons. This helium becomes trapped in underground reservoirs along with other gases and can be recovered during natural gas extraction.

Humans have used geothermal resources for thousands of years

In North America, Indigenous peoples viewed hot springs as sacred places and used them for medicinal purposes, cooking, and surviving cold weather. The ancient Greeks and Romans also viewed them as sacred, partaking in hot mineral baths to relieve ailments and using them for space heating.

Some geothermal power plants make electricity using a secondary fluid

Direct dry-steam systems pull underground steam into a turbine-generator system, while flash and double-flash cycle systems spray extracted liquid water into a low-pressure tank, causing it to rapidly vaporize—"flash"—before moving to the turbine. Binary cycle systems use the extracted steam and water to flash a second fluid that easily boils, which then drives the turbine.

In nuclear reactors, water acts as a coolant and moderator, slowing neutrons produced in nuclear reactions so they are more likely to interact with nuclear fuel and generate sustainable energy.

An overview of helium, the nonrenewable resource that's lighter than air

The second element in the periodic table naturally forms deep underground over the course of billions of years through the decay of radioactive elements, but it is used and lost to space at rates faster than it is generated. Because of this and its extensive applications in scientific technologies, scientists continue to seek avenues for its exploration, storage, and recycling.

Over a lifetime, the average American's nuclear power usage creates a hockey puck of nuclear waste

Spent nuclear fuel remains hot and highly radioactive for long periods, requiring submersion in cooling pools before being stored in dry casks and deep underground repositories. The potential recycling of nuclear waste is impeded by security concerns and dangerous reprocessing methods, particularly when obtaining fresh uranium is often easier.

The world's first geothermal power plant was built in 1913 in Devil's Valley

In Tuscany, Italy, Prince Piero Ginori-Conti of Trevignano established the plant nine years after creating a generator that powered five light bulbs using steam vents in the area. Within three years, a second plant was built with two generators, each with 10 times the energy output of the first.

A look at hydrothermal vents, where barophiles and hyperthermophiles survive boiling water

Discovered in 1977 during an exploration of the Galapagos Rift, these seafloor openings spew hot magma and chemicals that heat seawater to hundreds of degrees. Without the sunlight found at depths of less than 1,000 meters (3,281 feet), extremophiles in these environments convert released chemicals into energy to survive, alongside surviving extreme pressures.

Earth's core is leaking precious metals, including gold

Earth's core, containing 99.999% of all known gold, is leaking trace amounts of precious metals into the mantle. Advanced isotopic methods have detected this leakage at volcanoes in Hawai'i, providing new insights into the movement of material beneath Earth's surface.

The warmest waters in the ocean are found at hydrothermal vents—hot springs on the seafloor that discharge plumes of mineral-rich water.

The oldest nuclear fission reactor on Earth formed naturally in West Africa about 2 billion years ago, where groundwater enabled atoms in uranium deposits to split, releasing energy.

Where radon comes from and why it may be the most dangerous source of radioactivity

Released from underground bedrock before passing through soil, this radioactive gas is produced from the decay of uranium, thorium, and radium and accounts for about half of all human exposure to radiation. It is the leading cause of lung cancer among nonsmokers and can build up in enclosed spaces such as buildings without proper ventilation to dilute the gas.

Renewable energy basics

Discover the many benefits to using renewable energy resources, but what is it exactly? From solar to wind, it’s the fastest-growing source of energy in the world – and how we can use it to combat climate change.

Convection flows in Earth’s mantle drive the movement of tectonic plates

These processes transfer heat from Earth’s core to the surface via rising magma plumes, while cooler, denser rock falls into the mantle at rates similar to human fingernail growth. These rates are determined by combining seismic data with computer simulations to model Earth’s interior.

How we know what's deep inside the Earth, despite never traveling there

We'll likely never see the Earth's core, but we can make educated guesses about what it's like down there. Nearly as hot as the sun's surface and under impossibly high pressure, the inner Earths extreme conditions make it impossible to explore. Yet, seismic waves during earthquakes, volcanic eruptions, and light waves from the sun provide fascinating insights about our planet's mantle, crust, and core.

Uranium's ability to split easily makes it the most common catalyst for nuclear power

Uranium is commonly found in rocks, water, and soil worldwide, but significant industrial processes are needed to process and enrich it for efficient reactor usage. After being irradiated in reactors, it must be cooled down before disposal.

Methods for disposing of nuclear waste include melting it into a liquid to create glass, dumping it into graphite blocks, storing it in lead-lined rooms, and submerging it in deep pools of water.

Mining of rare earth elements risks leaking radioactive wastewater

The extraction and processing of REEs requires significant amounts of water, and poorly regulated projects can contaminate groundwater with acids and heavy metals. Toxic waste spills have paused work in several US mines since the 1980s, despite growing REE demand.

Without greenhouse gases, Earth's average surface temperature would be below freezing

Atmospheric molecules that absorb and emit infrared radiation from the planet's surface effectively trap additional incident solar energy that would otherwise escape to space. Without the greenhouse effect, the planet's average surface temperature would be approximately -18 degrees Celsius (0 degrees Fahrenheit).

Scientists investigate Earth's interior by studying seismic waves

Scientists investigate Earth's interior by studying seismic wavesBelow Earth's atmosphere lies the crust, which extends to the Mohorovičić discontinuity between five and 20 miles below Earth's surface. Below the crust lies the mantle, the liquid-metal outer core, and the solid inner core, which surpasses 5,200 degrees Celsius (9,392 degrees Fahrenheit).

The Geysers is the largest geothermal power complex in the world

Despite the Mayacamas Mountains area north of San Francisco lacking geysers, the name given by a grizzly bear hunter stuck after the construction of The Geysers Resort Hotel to accommodate tourists. Natural steam vents in the region are funneled into more than 12 geothermal plants, each capable of powering about 40,000 homes.

In 2009, accidentally drilling into magma provided time capsules of volcanic glass

While drilling for geothermal energy in Iceland's Krafla Geothermal Field, magma encountered at a depth of 2,100 meters quickly formed glass upon making contact with drilling fluid. By trapping dissolved gases, volatile chemicals, and the physical characteristics of magma before cooling, the glass acts as a time capsule of ancient volcanic activity and magmatic conditions.

Solar power is converting the sun's energy into thermal or electrical energy

Solar energy is the most abundant renewable energy resource. It can be captured in photovoltaic cells to generate electricity, solar heating and cooling technologies for temperature control, and concentrated solar power to drive steam turbines.

How the sun heats the Earth

We all know it: Without the sun's heat, the Earth would be uninhabitable. So how does it work? The sun fuses roughly 600 million tons of hydrogen every second, the energy from which bursts out into space—including toward our planet. Our atmosphere...

Scientists can determine the age of rocks, fossils, and other ancient samples by measuring how many radioactive atoms in the sample have decayed, a process that occurs at precise, well-known rates.

Atmospheric greenhouse gases trap thermal energy and make Earth habitable

The moon and Earth are at the same distance from the sun, but the moon experiences large fluctuations in surface temperature because it lacks an atmosphere to insulate it. Gases such as water vapor, ozone, carbon dioxide, and methane can intercept about 90% of the infrared radiation emitted by Earth's surface.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

Microreactors are 100 to 1,000 times smaller than traditional nuclear reactors but still generate thermal energy for heating or electricity by splitting atomic nuclei.

If the sun disappeared, we would not know about it for 8 minutes and 20 seconds, at which point the Earth would suddenly move in a straight line on its way out of the solar system.

The cycling of carbon via tectonic activity may have facilitated life on Earth

Plates sinking into Earth’s mantle pull carbon from the surface, helping stabilize the atmosphere and climate by removing greenhouse gases from volcanic eruptions. At the same time, magma is a significant contributor of heavy metals and other crucial minerals for life to the surface.

What fuels the sun?

The sun is our biggest source of heat and light, but how does this massive powerhouse continue to produce such amazing energy? Basically, it's a fusion reactor. At its core the sun produces all that solar energy through hydrogen fusing and converting into helium, over and over again. Learn more about the entire amazing and explosive process here.

Understanding why the thermosphere feels cold, despite exceeding 2,000 degrees Celsius

High-energy solar radiation can raise temperatures above 2,000 degrees Celsius (3,632 degrees Fahrenheit), but the air density in this layer is so low that there would be insufficient collisions between energized molecules and a person's skin to cause them to experience this warmth. Variations in the level of solar radiation reaching the layer cause it to swell and shrink.

Although they rely on radioactive elements to operate, everyday technologies such as electronic exit signs, some wristwatches, and smoke detectors are not dangerous, unless they are damaged and their radioactive material is inhaled or swallowed.

Everything with a temperature above absolute zero emits light at nearly all wavelengths

Thermal radiation results from random motions of particles that make up an object, which only theoretically cease at 0 Kelvin, or -273.15 degrees Celsius. The greatest intensity of thermal radiation, also known as blackbody radiation, is emitted at a characteristic wavelength corresponding to the object's surface temperature.

Nuclear batteries generate electrical currents using radioactive materials

Rather than using electrochemical reactions to produce the electrons that flow through a circuit, isotopes like nickel-63 undergo beta decay—emitting electrons—which a semiconducting material can absorb to establish a charge imbalance that generates current. Such batteries could provide low-power energy for decades.

Nuclear fusion, where the nuclei of two atoms are combined, can produce near-limitless clean energy, but requires extreme conditions to kickstart because of the natural repulsion of atomic nuclei.

Extreme temperature resilience appears to be temporary for tardigrades

Although often considered indestructible, scientists observed these creatures could endure temperatures near 150°C for only a few minutes in their tun state. Outside this state, only half the samples in a Danish study survived 37.1 degrees Celsius (98 degrees Fahrenheit) for 24 hours, making tardigrades extremotolerant rather than extremophiles.