Tesla's alternating current power's most of the world's electric grids

Thomas Edison publicly executed animals with AC to convince the public of its dangers

J.P. Morgan first backed Thomas Edison's direct current system, seeing electricity's potential to usurp John D. Rockefeller's kerosene empire. Despite the investments and smear campaign against alternating current, alternating current ultimately won public support after lighting the 1893 World's Fair, after which Morgan would fund Tesla's wireless transmission tower.

Named after Nikola Tesla, who pioneered alternating current power systems, the Tesla coil was the first device to wirelessly transmit electricity.

Watch a timeline of the history of electricity, from observations of static electricity in antiquity to the War of the Currents—a rivalry to establish the ideal system for electric grids.

Niagara Falls helped decide the battle between AC and DC power

In the 1890s, Niagara Falls became the proving ground for alternating current (AC) when Tesla and Westinghouse built the first large-scale AC hydroelectric plant—defeating Edison’s push for direct current (DC) in the US electrical system.

Tesla's first successful AC prototype used a metal shoe polish tin for a rotor

After leaving his position working with Thomas Edison, Tesla partnered with George Westinghouse to promote alternating current systems as a more viable, scalable solution to electricity transmission.

Alternating current was used to commit the first execution by electric chair

Dubbed the "executioner's current," the device was designed in Thomas Edison's lab by Harold Brown—an opponent of George Westinghouse and Nikola Tesla. The effort aimed at discrediting AC technology and gain favor for Thomas Edison's direct current as part of "The Current War."

The world's first AC hydroelectric power plant incorporated Tesla's engineering

Built at Niagara Falls, New York, the plant alternating current electricity was hailed as the future of power generation. Tesla's fascination with Niagara Falls is traced to his seeing a photo of the waterfalls when he was still a child.

The history of the North American power grid, which is composed of five major grids

Thomas Edison's Pearl Street Station was the first US commercial power plant, burning coal to power lamps for some Manhattan residents. Over time, local power plants would be bought out by larger ones, forming interconnected systems spanning multiple states. Today, the Eastern Interconnection and Western Interconnection are the largest of these systems.

Despite promoting alternative current, Nikola Tesla did not invent it

The technology was developed by Hippolyte Pixii in 1832, almost 25 years before Tesla was born. Other myths about Tesla include that he invented the transformer, radio, and the induction coil, which was invented by Nicholas Callan in 1836.

Niagara power helped electrify early New York City

Tesla's AC system at Niagara Falls was so successful that electricity generated there lit up Broadway theaters and powered NYC's subway system in the early 1900s.

George Westinghouse purchased Tesla's AC technology patents for $60,000

The seven patents in alternating current motors and power transmission formed the basis for a system of technologies including generators, transformers, and lighting. Nikola Tesla spent half the funds on a new laboratory to develop new inventions.

Nikola Tesla embraced showmanship when promoting ideas ahead of their time

He once electrified himself during a live demonstration to illustrate the safety and power of alternating current, and his presentations often featured arcing coils, glowing lights, and bold claims about a future of wireless power.

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

Nikola Tesla was born in modern-day Croatia and moved to the US in 1884

His interest in electricity came from his mother, who invented small household appliances during Tesla's upbringing. Upon arriving in America, he began working for and improving upon the electrical inventions made in Thomas Edison's lab.

Nikola Tesla's biggest dream was a worldwide network of wireless power transmission

He built the Wardenclyffe lab and a massive prototype transmission tower to develop trans-Atlantic transmission, but it was never operational. The concept was based on incorrect assumptions about Earth's conductivity, but it inspired subsequent efforts for wireless systems.

While charges consistently move in the same direction in a direct current, the flow of charges changes multiple times per second in an alternating current.

The engineering underlying the electric grid and why it needs to be modernized

The system includes generators for producing electricity and millions of miles of transmission and distribution lines to transport the energy. The substantial increase in the number of electronic devices and electrical demand since the construction of much of the grid in the mid-1900s has strained infrastructure, requiring continuous upgrades and massive investments in new construction.

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

Nearly 40% of American cars were electric in 1899

They were most common in cities, where battery swap stations allowed drivers to "refuel" their vehicles reliably. Innovations in combustion engines caused electric cars to lose ground until environmental policies and advances in battery technology revitalized interest.

Before the invention of transistors, vacuum tubes made radio possible

Discovered by Thomas Edison, vacuum tubes allow electrical currents to travel through empty space. Later modified into a diode—keeping current flowing in only one direction—vacuum tubes allowed electronics to turn alternating current into direct current.

Tesla's lack of business savvy and inability to commercialize led to his obscurity

For decades, despite pioneering technologies for large-scale electrical systems and telecommunications, Nikola Tesla had been forgotten to history. Rather than monetizing his work and becoming more well known, his inventor-first mentality saw him sell off lucrative patents to fund new experiments in the short term.

Discover why Texas runs its own electric grid, separate from the other US interconnections

In 1935, electrical utilities in the Lone Star State opted to rely on the state's own fossil fuel reserves to power an independent electric grid. While this prevented the federal oversight required for the Eastern and Western Interconnections that span multiple states, it also meant Texas's grid was unable to draw sufficient backup power during the winter 2021 power grid failure.

Explore a gallery of electric vehicles from before 1920

In 1884, Thomas Parker invented the first practical electric car in London. By the turn of the century, early EVs were seen on the streets of Washington, DC. Automaker promotional materials included photographs of cars on mountain roads and other terrains.

Transformers change the current and voltage across a set of wires by wrapping them around a magnetic core and using the magnetic field of one wire to induce a current in the other.

Despite electric usage concerns, EV charging accounts for less than 1% of grid load

Other popular myths about EVs include battery failure concerns—failure rates are less than 1% on newer models—and that there are no places to charge cars, though both at-home outlets and more than 77,000 stations on the road are available.

Electric vehicles have been around since the 19th century

The first EVs ran on rechargeable lead-acid batteries, which could travel 60 to 80 miles on a single charge. Women preferred these vehicles, which were quieter, less smelly, and did not require turning a hand crank to start the engine.

Thomas Edison created the first strand of electric Christmas lights in 1880

Edison strung electric bulbs outside his laboratory in 1880, and his business partner Edward H. Johnson first wrapped a tree in lights in 1882. It wasn’t until the lights were commercialized in 1917 that they became common in household Christmas decorations.

Nikola Tesla's original laboratory was recognized as a historical site in 2018

Beginning in 1901, the Wardenclyffe Tower was built on Long Island, New York to transmit electrical power through Earth's atmosphere. The project was abandoned before becoming operational due to limited funding, and was demolished for scrap in 1917 to help pay off Tesla's debts.

Over-the-air updates, pioneered by Tesla, have become the industry standard

Tesla's innovative direct-to-consumer sales model and online ordering system changed car-buying, and the Model S, which had a 200-mile range, forced other automakers to enhance their EV offerings and rethink vehicle design.

A collective effort from multiple scientists and inventors led to the light bulb

While Thomas Edison's thin carbon filament design made light bulbs commercially viable, prior contributions, such as Joseph Swan's development of the first successful incandescent filament electric lamp, made its eventual invention possible.

More batteries in the power grid would create an on-demand energy reservoir

Most power grids are inefficient because they require enough generation capacity at all times to avoid blackouts. This means at any given time, as much as 50% of generating capacity at power plants can go unused. Batteries would reduce this inefficiency and allow for real-time adjustments.

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.

Why decarbonizing the entire electric grid is impossible with its current infrastructure

Fossil fuel plants can be built anywhere and have thus typically been built near highly populated areas, such as coastal cities, where electricity demand is high. However, certain renewable resources operate most efficiently in specific regions, such as wind turbines in the Midwest, and therefore require substantial transmission infrastructure to be constructed to transport the generated electricity.

Guglielmo Marconi overshadowed Nikola Tesla through commercialization

Despite Tesla envisioning wireless power and communication earlier, Marconi developed practical implementations of wireless communication, including transmitting the first transatlantic radio signal. The technology, which facilitated telegraphy critical for warships and navies, earned Marconi the 1909 Nobel Prize in physics.

As of 2025, China used the most electricity of any country, accounting for 33% of the total global demand and more than twice that of the US.

How microgrids can modernize electric grids to meet 21st-century demands

Just as having a single, outdated internet service provider leaves an area helpless in the case of an outage, failures in the electric grid can be devastating to communities. For this reason, hospitals, data centers, and other structures have their own backup power supplies. However, decentralized microgrids would provide areas with their own electricity generation and storage, thereby reducing overall grid load and reliance while enabling better electricity management.

J.P. Morgan provided Nikola Tesla with funding for the Wardenclyffe Tower

The structure was part of a project to transmit electricity and communication signals wirelessly across the globe. Shortly after construction began, Guglielmo Marconi beat Tesla to the punch and transmitted a trans-Atlantic signal, preventing Tesla from getting additional funding to finish his project.

Fluorescent bulbs can be illuminated by overhead power lines without making contact

The electromagnetic fields produced by the alternating current in transmission lines can induce the motion of charges in nearby objects. This motion yields electric currents that can light up bulbs but are too small to harm humans.

View breakdowns of the world's and each nation's electricity comes from

These charts show how the shares of generated electricity sources—solar, wind, hydro, nuclear, bioenergy, oil, gas, and coal—have changed since 1985. Since 2010, an increase in renewable sources has offset the share lost by nuclear and fossil fuels.

Learn how critical services, infrastructure, and people would be impacted by a US-scale blackout—a nationwide, long-term failure of the electric grid.

Establishing the wind power grid required incentives, reliability, and affordability

Although wind was harnessed to generate electricity for individual buildings in the late 1800s, high costs, mechanical issues with turbines, and better fossil-fuel alternatives delayed wind power's widespread growth. After the oil crises of the 1970s, governments sought alternative energy sources and, in the decades that followed, provided tax credits to expand the wind power market.

In 1898, Nikola Tesla wowed a crowd by controlling a boat with no visible connection

Some onlookers thought it was a trick, such a a monkey being inside the boat, rather than mind control or some other metaphysical phenomenon. In reality, Tesla was pioneering radio waves, proving wireless control was possible.

A pair of engineers began Tesla to prove the viability of electric vehicles

Martin Eberhard and Marc Tarpenning sought to design a high-end electric sports car for environmentally motivated, affluent buyers. The Tesla Roadster would be the first highway-legal car to use lithium-ion batteries.

Read about the nine depictions of Nikola Tesla in media through 2020

Portrayals include comedic takes, like John C. Reilly's performance in Comedy Central's "Drunk History" series, and more serious interpretations, like Nicholas Hoult's performance in Alfonso Gomez-Rejon’s historical drama, "The Current War."

Electromagnetic induction creates electricity from a changing magnetic field

The phenomenon was discovered in 1831 by Michael Faraday when an electric current was induced in a wire wrapped around an iron ring after a second wrapped wire not connected to the first was connected or disconnected from a battery.

High fuel prices and fuel shortages revived dormant interest in EVs

Electric vehicles, in the form of motorized carriages, predate the invention of the gas-powered automobile by over 40 years. The latter's affordability made it more popular until technological advances made EVs more viable to consumers in the early 2000s.

The unpredictability and brevity of lightning make lightning power impractical

While a typical lightning strike provides 30,000 amps at 300 million volts, the bolt only lasts about 30 microseconds. If the electrical surge could be captured—assuming one knew beforehand where it would strike—it would only provide enough electricity to power one home for about 6.4 hours.

AI's growing energy demands are driving tech companies to consider nuclear power

Big Tech has rebranded nuclear power as a green solution to address the strain on the grid from millions of people using power-hungry AI tools. As of mid-2025, generating one image uses as much electricity as charging the average smartphone, or leaving a household light bulb on for 87 consecutive days.

The speed of electricity may refer to the movement of electrons, which is on the order of a fraction of a millimeter per second, or energy, which is near the speed of light.

Explore a timeline of Tesla through 2025

Initially called Tesla Motors, the company was renamed Tesla Inc. in February 2017. Its Model Y became the world's bestselling EV worldwide by the end of 2023, overtaking the Model 3's title from 2020.