In a conversation over dinner, Volta and his colleague Luigi Galvani debated the cause of their frog legs twitching when touched by two different types of metal. While Galvani believed something in the frog's muscles was responsible for the reaction, Volta speculated that it might be the liquid in the frog's legs reacting to the metals. Putting his hypothesis to the test in a series of lab experiments, Volta tried stacking a variety of metal plates and wrapping them in rags soaked in brine, and found that he was able to generate and measure an electric charge. His creation, the Voltaic Pile, was the world's first electrochemical battery.

Carrying on from Hans Christian Ørsted's discovery of electric conductivity and André-Marie Ampère's work in polar magnetism, Faraday reasoned that an isolated magnetic pole should move constantly around a current-carrying wire. Using a small mercury bath atop a bar magnet to make a conductive magnetic field, Faraday created a second magnetic field by suspending a stiff wire into the mercury and connecting it to an electric battery. As he observed the wire start to spin clockwise over the the base, it was clear that he'd found a reliable method to convert electrical energy into mechanical energy—a discovery that served as the basis for every electric motor that followed.

Edison filed his patent for “an improvement on Electric Lamps” on November 4th, 1879 and first demonstrated his invention to the public on New Year's Eve. The small, glass vacuum bulb housing a platinum filament was designed to require far less electrical power than the industrial arc lamps of the day, making electric light an accessible commodity for home use. “We will make electric light so cheap,” he told the crowd gathered at his Menlo Park Laboratory, “that only the rich will be able to burn candles.”

Pearl Street's six coal-powered “Jumbo” dynamos supplied up to 600 kilowatts of direct current power to 82 customers across a square-mile grid centered in lower Manhattan. Among Edison's first customers were the US Post Office and The New York Times Building. In their report following the plant's opening, the Times noted, “To turn on the light nothing is required but to turn the thumbscrew. No matches are needed, no patent appliances.” By 1884, Pearl Street served 504 customers and powered 10,164 lamps.

Early in his engineering career, Parsons left development of rocket-powered torpedos to lead the electrical equipment development team at Clarke, Chapman and Co. His compound steam turbine employed several stages in a series to restrict the expansion of steam and permit the greatest extraction of kinetic energy without damaging the turbine blades through excessive speed. When connected with an electrical generator, also of his original design, the turbine would go on to make electricity more abundant and affordable for a growing customer base.

Early attempts at gas turbine development were rife with failure, due in large measure to a lack of materials that could withstand high pressures, temperatures, and rotational speeds simultaneously. By conceiving of a machine that used steam injection between the combustion chamber and the turbine, Ægidius was able to keep the combustion gases cool enough to run the turbine above production speed without overheating. His implementation of steam injection to augment power and improve thermal efficiency is still used in gas turbines today.

It was a strange notion to think that a water reservoir could effectively serve as a battery, but not too strange for the engineers at Connecticut Light and Power. By using excess energy from a nearby steam power plant to pump water from the Housatonic River into a reservoir at a 230 foot boost in elevation, the company could keep a significant amount of potential hydroelectric energy standing by for use at a moment's notice. When supplemental power was needed during hours of peak consumption, valves at the reservoir would open and allow the water to flow downhill, driving a water turbine and feeding power back into the grid. Pumped-Storage hydroelectric utilities are still used today, and are an excellent means of reducing the number of power plants needed to meet peak demand.

In the midst of the Great Depression, infrastructure projects played a key role in rehabilitating the American economy and making electricity more affordable for homes and businesses. With a development time of twenty-nine years, and an aggressive five years of construction, the Hoover Dam was the most ambitious hydroelectric project ever attempted in its day. Composed of 6.6 million tons of concrete and 582 miles of cooling pipes, the massive hydroelectric plant was capable of outputting an impressive 1,345 megawatts.

In late 1941, as World War II raged in Europe, a group of engineers at GE's factory in Lynn Massachusetts received a secret mission: they were tasked with redesigning and commercializing the Whittle jet engine, first developed by RAF officer Frank Whittle. Given only six months to complete the task, the team worked day and night, guided only by Whittle's blueprints and a few British engineers. Less than a year later, on October 2nd, 1942, their engine powered the initial test flight of the first American jet, the XP-59. The axial flow compressor designed for the engine is still being used in almost every modern jet engine and gas turbine in operation today.

In an address to the UN General Assembly in 1953, President Eisenhower called for the creation of an international atomic energy agency, and pledged the United States' “determination to help solve the fearful atomic dilemma — to devote its entire heart and mind to finding the way by which the miraculous inventiveness of man shall not be dedicated to his death, but consecrated to his life.” Shortly thereafter, GE contributed a turbine and generator to the 2-megawatt “SM-1” nuclear reactor at Fort Belvoir in Virginia. The SM-1 reactor was both the first nuclear power plant to be connected to an electric grid and the first to deliver nuclear-generated electricity for public use in the United States.

When Professor Giovanni Francia began his experimentation with harnessing solar energy to generate power, it bore no resemblance to the early photovoltaic systems that were being developed in the United States. Instead, Francia built a complex of reflector discs to converge sunlight onto a single receiver in the middle of the array - the receiver, in turn, would use the heat gathered by the sunlight to produce steam and power an electrical generator. While subsequent Concentrated Solar Plants would transition to the use of molten salts rather than steam, Francia's design for light convergence through an array of reflectors is still used today.

America's first wind farm was built on a small piece of land owned by the Crotched Mountain Rehabilitation Center by U.S. Windpower in New Hampshire. It opened to a great deal of local fanfare, welcomed by area residents as a symbol of technological innovation and progress. Using a series of twenty turbines, each capable of outputting 30 kilowatts, its maximum total generating capacity was 600 kW. Though it only lasted a relatively short time before being decommissioned due to inconsistent power output, the wind farm managed to capture the public's imagination, and inspired further innovation in American Wind Power.

The 1990s saw significant advances in photovoltaic technology, including the construction of the first grid-connected PV system in 1993, and the development of the first 30% efficient solar cell in 1994. In less than two decades since the world crossed the 1,000 MW threshold, massive advances in solar tech have led to a worldwide boom in solar power. In 2017, the total global operating solar power reached 405 GW, with nearly a quarter of that capacity installed that same year.

On Friday the 17th of June 2016, GE and EDF officially inaugurated the first ever combined-cycle power plant equipped with GE's 9HA gas turbine in Bouchain, France. Before it opened, Bouchain had already achieved a huge milestone: In April 2016, the turbine received a Guinness World Records™ title for powering the world's most efficient combined-cycle power plant, achieving a 62.2% efficiency rating for the first time. This was not the last time a GE gas turbine achieved a world record: in 2018, Nishi-Nagoya power plant's three 7HA turbines broke the record with a verified efficiency of 63.08%.

On April 17, 2017, GE and Southern California Edison debuted the world's first battery-gas turbine hybrid in Fairfield, California. The addition of battery power allows SCE to keep the turbine in standby mode - no fuel required. The plant, which combines 10 MW battery energy storage system with GE's 50 MW LM6000 aeroderivative gas turbine, reduces greenhouse gas emissions and pollution by 60 percent and water consumption by approximately 45 percent. In 2017, the Hybrid EGT received Edison Electric Institute and ESNA innovation awards.

On March 1, 2018, GE Renewable Energy announced its plan to build the world's largest offshore wind turbine. The Haliade-X will tower 230 meters and its 12 MW electric generator will produce up to 67Wh annually. That's the equivalent power to the energy needs of up to 16,000 European homes. Scheduled to ship in 2021, the Haliade-X will produce 45% more energy than any wind turbine available today.