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

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.

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.

Niagara's flow is changed artificially to accommodate tourists and power generation

The natural wonder is also the site of great engineering feats, from the Welland Dam that first allowed ships to travel from the upper lakes to the St. Lawrence Seaway, to one of the first hydroelectric dams.

Niagara Falls is New York State’s biggest electricity producer

The Robert Moses Niagara Power Plant and Lewiston Pump-Generating Plant together produce up to 2.6 million kilowatts—providing about 20% of New York State’s hydropower and supplying electricity to over 3 million homes.

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

In 1879, Thomas Edison’s light bulb relied on direct current, but such currents can't efficiently transmit power over long distances. Nikola Tesla introduced alternating current, which feature far fewer energy loses. Despite Edison’s attempts to discredit AC, Tesla proved its efficiency by lighting the 1893 Chicago World’s Fair.

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.

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

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.

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'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.

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.

Water from four Great Lakes feeds Niagara Falls

Niagara Falls is powered by water from Lakes Superior, Michigan, Huron, and Erie. The Great Lakes basin spans over 260,000 square miles and holds nearly 20% of the world's surface freshwater—about two-thirds of which passes over the falls.

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.

Engineers shut off Niagara's American Falls for six months in 1969

In June 1969, the US Army Corps of Engineers diverted the Niagara River to halt flow over the American Falls. The dry riverbed allowed geologists to study erosion and remove dangerous rock buildup.

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."

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.

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.

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

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.

The US Army Corps of Engineers once stopped water from flowing into Niagara Falls to prevent long-term erosion.

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.

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.

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.

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.

Niagara Falls consists of three different waterfalls

The famous landmark is made up of the American, Canadian, and Bridal Veil falls. Of the three, Bridal Veil is the smallest and forms the other boundary of a small slice of area known as Luna Island, where tourists can view the scene.

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.

Whirlpool Rapids formed in a matter of days during the last ice age

Niagara Falls' dramatic whirlpool rapids were created in a matter of weeks when the retreating Falls intersected a buried ice age riverbed—generating North America's largest standing waves.

Niagara Falls flows over 400-million-year-old layered rock

The falls cut through distinct layers of ancient rock: a hard cap of Lockport Dolomite sits atop softer layers of Rochester and Queenston Shale. This structure allows the falls to maintain a steep vertical drop as erosion undercuts the caprock.

Niagara Falls generates its own microclimate

Constant mist from the Falls produces localized weather effects, including rare ice formations that can rise over 100 feet high in winter.

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.

Take a drone tour of a Tesla factory

The first of Tesla's large-scale European manufacturing plants for its electric vehicles was opened in Berlin in 2022. It—along with other facilities in Nevada, New York, Texas, and Shanghai—collectively manufactures solar panels, batteries, and other energy collection and storage products.

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.

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.

Amateur engineers built America’s first great infrastructure project

With no engineering schools in the US, the Erie Canal was designed and built by self-taught amateurs who improvised new methods and became known as the “Erie School of Engineering.”

Wind turbines explained

Wind turbines have powered homes since 1887, and today they’re stronger, quieter, and more reliable than ever. Offshore wind could power millions and grow fast enough to meet climate goals.

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.

The first rooftop solar panels were installed in 1883

In 1883, New York inventor Charles Fritts created the first solar cell by coating selenium with a thin layer of gold. The cell achieved energy conversion rates of 1 to 2% compared to the 15 to 20% of modern photovoltaics.

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

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.

Tesla's production of a high-performance electric vehicle revived the EV industry

The Model 3 shifted public perception by showing that EVs could be fast and desirable, and built at scale. However, at one point, Tesla built an entirely manual production line in a tent outside its main factory to keep up with demand.

Niagara’s frozen river once hosted winter carnivals

Before a 1912 collapse, winter ice bridges across the river were so thick that entrepreneurs built bars, photo studios, and entire carnival midways on the frozen surface.

Niagara Falls stopped flowing for a full day in 1848 due to ice

In March 1848, ice jams halted the Niagara River entirely for over 24 hours, allowing people to walk on the riverbed—a rare event that drew international headlines.

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.

Niagara Falls was a key Underground Railroad crossing point

In the mid-1800s, the Suspension Bridge near Niagara Falls connected the US to Canada and served as a frequent crossing location for people escaping slavery via the Underground Railroad.

A dispute about the origin of twitching frog legs led to the invention of the first battery

Experiments by Luigi Galvani on exposed frog leg nerves showed activity when they were hung from iron railings and brass hooks, suggesting the existence of "animal electricity" that discharged when connected to metals. Alessandro Volta's voltaic pile, which stacked metals with an inorganic electrolyte, showed that electricity originates from chemical reactions.

Why is hydropower important when other power sources go dark?

Hydropower can ramp up, recoup shortfalls, and stabilize the grid nearly instantaneously. A new study quantifies the energy source’s contribution to grid stability.

When Tesla died in 1943, the FBI seized his property for national security

Although Nikola Tesla had become increasingly eccentric in his later years, the US government wanted to ensure plans for a possible secret weapon didn’t fall into enemy hands during World War II.

Explore the technical side of the Erie Canal

Listen to this podcast from Northwestern University exploring the canal’s groundbreaking infrastructure—from locks and aqueducts to its role as America’s first large-scale engineered waterway.

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.

Niagara Falls is slowly eroding backward toward Lake Erie

At its current erosion rate of roughly one foot per year, Niagara Falls is expected to retreat all the way to Lake Erie in about 50,000 years.