Explaining how water's movement between different salt concentrations can generate electricity

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.

How electricity is generated by heating water into steam, which rotates magnets

Electrical current—the flow of electrons in a wire—can be produced when exposing a wire to a changing magnetic field. By rotating the magnets, as occurs in a turbine-generator system, the field changes become cyclical. This produces alternating current—flow that moves forward and backward—converting mechanical energy into electrical energy.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

The moon's gravity pulls water from Earth's poles to produce tides

By attracting all parts of the Earth to varying degrees based on their distance from it, the moon produces an overall pressure that drives water toward the opposite sides of the Earth along the Earth-moon axis, not unlike how squeezing a grape causes it to bulge. This creates high tides along the axis on opposite sides of the Earth and low tides along the perpendicular axis. Without significant water to displace, most lakes do not experience noticeable tides.

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.

An overview of hydropower

Hydropower, or the use of the natural flow of moving water to generate electricity, is one of the oldest and largest sources of renewable energy.

Transpiration drives water movement through a plant’s vascular system

Water evaporates from the leaves, creating tension that pulls more water upward from the roots through the xylem—the equivalent of plant blood vessels. This process is supported by water molecules sticking to each other (cohesion) and xylem walls (adhesion).

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.

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.

How salt, sunlight, and wind drive ocean currents

The Atlantic Meridional Overturning Circulation plays a critical role in regulating earth's climate, but is threatened by climate change. Explore the effects of temperature, density, and salinity on ocean currents in this 13-minute PBS video.

Windmills can be designed to pump groundwater for irrigation or land drainage

A gearbox within the windmill converts the windmill's rotation into the vertical motion of a piston that pushes water up a pipe. It also drives the rotation of an Archimedes screw to move water to higher elevations.

As of 2025, wave power projects remain in early research and testing phases

Waves can become a steady source of renewable energy because they do not pause like wind and solar power do. However, funding gaps and the effects of storms, salt exposure, and biofouling—mussels and other sea creatures attaching to wave machines—have presented challenges in scaling the technology beyond testing sites.

Data centers' electrical needs create increased water demands beyond cooling

Each query uses approximately one single-serving water bottle per conversation, but water is also used for steam cycles and cooling in power plants that generate electricity for data centers. Newer cooling methods, such as immersion cooling, where servers are submerged in fluids that don't conduct electricity, can minimize water use.

An overview of oxygenic photosynthesis, which releases oxygen from breaking down water

Within the membranes of chloroplasts, electrons in pigments are energized by light and transferred across a series of molecules until they create the energetic NADPH molecule. This transfer also powers a hydrogen pump, which creates an ion imbalance that, when relieved, produces energetic ATP molecules. Outside the membranes, both NADPH and ATP are used to synthesize G3Ps, which are funneled into other metabolic pathways to produce sugars.

Explaining the Leidenfrost effect, where water can hover and move against gravity

Water droplets can glide across surfaces whose temperatures are well above water's boiling point. This heat instantly vaporizes the bottom of the droplet, creating a layer of steam that the rest of the droplet rides and bounces upon. This can be seen when sprinkling water on skillets to determine if the surface is hot enough to cook on.

How water pressure affects the body

The extreme conditions of the deep sea include increasing amounts of pressure as explorers and organisms descend into its depths. The major danger for both fish and humans is the way pressure changes how body tissues absorb chemical molecules...

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.

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

Most advanced touch screens rely on electrical charge in your skin

Capacitive touch screens store electrical charges in an electrostatic grid of tiny wires. When we touch the screen a tiny electrical charge is transferred from the screen to the finger to complete a circuit (since skin has positive and negative charges). This connection creates a voltage drop on that point of the screen. Cloth, however, doesn't conduct electricity, which is why humans can't wear thick gloves and operate their smartphones.

How to make your own DIY ionic thruster

In the search for more efficient, sustainable types of propulsive thrust, scientists have dabbled in developing engines using ionic thrust, a type of propulsion using the attractive force of oppositely charged ions. First introduced by a Russian...

We hear because soundwaves are converted into electrochemical signals in our ears

This science teacher video systematically walks through the biology of the outer, middle, and inner ear. The explanation starts with the auricle, an external part that funnels sound through the auditory canal, and the tympanic membrane (the ear drum), which vibrates when sounds hit it. Beyond that, as the video details, is the eustachian tube, which is connected to the back of our throats and allows air to pass in and out to equalize ear pressure.

Will-o'-the-wisps may be the result of microlightning between bubbles

Methane and air bubbles moving through water can generate small sparks between them, which can ignite gas. The above-ground phenomenon may have historically been the result of passing travelers igniting swamp gas with their lanterns. (Some readers may experience a paywall.)

Learn why water can take millions of years to be recycled via the hydrologic cycle

While a single drop of water spends an average of nine days in the atmosphere before precipitating back to Earth, it can spend thousands of years in the ocean before evaporating, and hundreds of thousands of years deep in rock layers before being released as steam in volcanic eruptions. Some water molecules have been trapped in Antarctic ice sheets for millions of years since they last moved through the water cycle.

View a map of the balancing authorities managing electric systems and costs throughout the continental US

These are made up of utilities, Power Marketing Administrations—hydropower marketers from the Department of Energy—and groups of utilities that have formed regional entities called Regional Transmission Organizations or Independent System Operators. Collectively, balancing authorities ensure supply meets demand and can direct utilities to implement rolling blackouts to prevent permanent damage to electrical equipment.

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.

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.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

Massive blooms of microscopic plankton called dinoflagellates produce the neon blue light seen in glowing tides.

Planeterrellas create artificial auroras that mimic the atmospheric displays of light by setting up an electric field between two metal balls in a jar filled with a small amount of air.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

Dirty lightning is a thunderstorm created from friction between rising and falling flows of ash and smoke during volcanic eruptions.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

See how fireworks are made and learn how metals like magnesium and copper are responsible for different colors.

Waves off the coast of Nazaré, Portugal, can reach over 100 feet and are caused by the area's deep underwater canyon geography

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

How Amazon operates a 'flywheel' business model, a self-reinforcing cycle that drives continuous growth

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.

Watch how viruses like Ebola can spill over from animals to humans—and vice-versa.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

Stanford built a Google Maps for the Roman Empire, revealing how much it cost to travel in the ancient world

Planarian flatworms are small, aquatic worms with exceptional regenerative capabilities. When cut, the worms can regenerate multiple bodies in a matter of weeks.

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

Researchers believe the brain consolidates memories, processes emotions, and plans for the future during dream states