Unlike solar panels, which convert sunlight directly into electricity, concentrated solar power systems focus sunlight to heat a material that boils water, which then drives a turbine-generator to produce electricity.

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.

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 osmotic power systems, the natural movement of water from regions of low to high salt concentration is used to generate electricity from pressurized water.

Sand 'batteries' can store excess electricity from the power grid as thermal energy

Energy collected from solar or wind power is used to heat insulated silos full of sand to temperatures as high as 450 degrees Celsius (842 degrees Fahrenheit), which can be retained for long periods. These thermal energy storage systems can be designed to boil water and generate electricity when needed.

In the photovoltaic effect, light generates electricity by creating a charge imbalance after knocking electrons out of atoms in the semiconducting materials of solar cells.

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.

Space-based solar power systems may beam energy to Earth

Researchers have successfully collected power from solar panels on a plane and transmitted it to a receiver on Earth's surface, achieving a milestone for space-based energy. The proof of concept is a precursor for a satellite-based solar farm that would transmit energy 24 hours a day.

Desalination involves costly, energy-intensive methods for producing freshwater

Thermal desalination heats saltwater to produce steam, and reverse osmosis forces saltwater through a membrane that only allows water through. In both cases, freshwater is collected and remineralized for consumption, while wastewater brine is often returned to the ocean, where it may harm marine organisms.

A 1,000 square kilometer patch of solar panels in Africa can power most of Europe

The $500 billion Desertec initiative would have constructed massive solar farms in the Sahara and expansive electrical transmission networks across continents. However, the plan was built on concentrated solar power technology, which is more expensive and less practical than photovoltaics.

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.

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.

Solar energy alone can fully power the world if transmission hurdles can be resolved

When light strikes a photovoltaic cell, electrons are loosened, which travel through a circuit where the energy can be used. Distributing energy from high solar intensity regions and storing energy for non-daylight hours is logistically challenging and costly.

Solar sails use light as a means of propulsion

Photons possess momentum and can transfer it to objects they strike or bounce off, imparting radiative pressure, or a light-based force over a small surface area. Lasers fired at observational equipment with specially designed sails can theoretically use this mechanism to accelerate up to 20% the speed of light.

Larger shares of solar power generation produce larger energy demand curves

Because solar energy is only available during daylight hours, transitioning an electric grid to solar requires significant ramp-ups and ramp-downs of other energy sources during mornings and evenings to compensate. Widespread adoption of affordable energy storage solutions can soften these curves.

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.

Clean energy technologies are more mineral-intensive than burning fossil fuels

Solar panels use silver due to its high conductivity, hydropower plants use chromium in their steel alloys, and geothermal plants need titanium to withstand abundant heat and pressure. Lithium—used in energy storage—is expected to see over 500% increased demand from 2020 to 2025.

Visualize how alternating currents—electricity that periodically changes direction—are generated by rotating magnetic fields, as occurs in turbine-generator systems.

Since 2026, the Large Hadron Collider has provided heat to thousands of French homes and businesses through a system that harnesses hot water from the accelerator's cooling circuits.

Hydrogen fuel cells, which combine hydrogen and oxygen to generate electricity and water, can be run in reverse to produce hydrogen fuel from water.

If two strands of conducting materials are connected at two junctions, electricity can be generated if one junction is heated while the other is cooled—a phenomenon known as the Seebeck effect.

A composite of telescope images of the sun, which each reveal unique solar features

While traditional cameras can reveal sunspots—cooler regions on the sun's surface—in visible light, x-ray detectors can highlight explosions of high-energy plasma and magnetic fields known as coronal mass ejections. Hydrogen-alpha filters can reveal clouds and filaments of material suspended in magnetic fields above the sun's surface.

Watch a server submerged in a fluid continue to run and stay cool by boiling the liquid away.

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.

The sun emits a continuous stream of plasma known as the solar wind

Composed of charged particles—electrons and ions—the solar wind is deflected around the Earth by the planet's magnetic field. More powerful solar storms, known as coronal mass ejections, are short-lived but produce huge clouds of plasma that disrupt technology upon reaching Earth.

Aquifer thermal energy storage systems bank water heated during the summer in aquifers—layers of porous rock, gravel, and sand filled with groundwater—which are then collected in winter to warm homes.

Data centers can be kept cool by circulating fluid over plates atop high-temperature components or by submerging equipment in non-corrosive oil that does not conduct electricity.

Heat pumps use an easily boilable chemical to regulate temperature

In air conditioners, warm air is pulled from a home to turn a refrigerant into a gas, which is then compressed, raising its temperature. The gas naturally releases this energy to the comparatively cooler environment when exposed, then expands and is reused in the system. Heaters run in reverse, with the refrigerant picking up energy from the comparatively warmer environment.

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.

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

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...

While carbon capture and storage systems collect carbon dioxide at the source, such as power plants, direct air capture systems extract it from the atmosphere.

Explaining concentrate and how concentrate-derived juice differs from its source

Developed to reduce the volume of goods—thus lowering storage and shipping costs—the concentration process uses pressure and heat to remove water, pulp, and skin from fruits. Concentrates provide significant flavor, sugar, and calories to foods in small quantities, but do not retain most of the fiber, vitamins, and other nutrients from the source fruit.

Solar panels can create pollinator-friendly habitats by protecting flowering plants

An example of agrivoltaics, where land is used for solar energy production and agriculture, the panels provide clean energy while also shading plants from excessive sunlight. Pollinator-friendly plants can improve water quality and reduce soil erosion by obstructing the wind.

Solar panel manufacturing begins with silicon extracted from sand

The silicon is purified and shaped into wafers less than 0.2 millimeters thick, coated and connected through a criss-cross pattern of narrow and wider metal, followed by multiple rounds of lamination before bonding to a weatherproof panel.

Cathode-ray tube televisions are examples of electron accelerators

CRT TVs work by converting electricity into heat, which causes electrons to be emitted from the rear of the device in three beams responsible for the colors red, green, and blue. Electromagnets direct electrons to phosphor molecules on the screen, which emit light and illuminate the pixels.

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

Artificial photosynthesis turns CO₂ into sustainable fuel

Carbon conversion focuses on a central perplexing question: if carbon dioxide is a leading driver of climate change, and fossil fuels are made of carbon-based molecules, can we devise a way to convert CO₂ into useful alternatives efficiently? This video breaks down a potential pathway using artificial photosynthesis, which uses sunlight to convert CO₂ into fuel.

Enough sunlight hits Earth in just 90 minutes to power the planet for an entire year

Despite this, in 2023, only 5.1% of electricity in the US came from solar energy. Solar panel technology has nonetheless made significant advancements since the 19th century, largely due to NASA's efforts in the space race.

Rain-catching tubes provide new hydropower source for tropical regions

An experiment in Singapore showed that charge separation could be established by rainwater flowing through narrow tubes. The separation, which creates a voltage, could be scaled up in regions of high rainfall to provide a clean energy source.

Explore global solar resources with this interactive map

One of the biggest challenges to deploying solar panels is whether electricity can be generated reliably when needed, day after day. This detailed interactive map calculates the solar power output potential of regions worldwide and provides a visual comparison between locations such as North Africa and the US Midwest.

When users prompt AI chatbots, both cooling systems that support data centers and power plants that rely on steam cycles to generate electricity for data centers contribute to water use.

Data centers require interconnected server- and building-level cooling systems

Computer equipment can be cooled by circulating cold air or water through the equipment racks, siphoning the heated fluid into a heat exchanger. This exchanger transfers thermal energy to building cooling systems, which can dispose of the heat by evaporative cooling—the way humans cool off by sweating—or via air conditioning.

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.

Space weather phenomena, including solar flares, coronal mass ejections, and solar wind, are driven by the sun's magnetic field and can affect Earth's ground- and space-based technological systems.

Electric grids that rely on solar power must compensate for reduced electricity generation during solar eclipses.

The International Space Station is powered entirely by large solar arrays

Launched in 1998, its original solar panels were designed to withstand no more than 20 years of wear from temperature swings and micrometeoroid impacts in space. Replacement panels that roll out like carpets have since been installed.

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.

View a breakdown of global electricity generation in 2025, led by coal power plants.

The first practical silicon solar cell was developed at Bell Labs

In 1953, scientists at Bell Labs attempted to develop a power source for phone systems in remote locations, as the dry battery cells lacked the necessary longevity. They experimented with solar power, but the selenium solar cells of the time were too inefficient, eventually leading to the usage of silicon.

How solar systems form

Learn how our sun, the planets, and other solar system bodies came to be with these videos and an infographic from NASA. Use this resource to visualize how the solar system formed and to model and describe the process.