The Statue of Liberty (Liberty Enlightening the World; French: La Liberté éclairant le monde) is a colossal neoclassical sculpture on Liberty Island in New York Harbor in New York, in the United States. The copper statue, a gift from the people of France to the people of the United States, was designed by French sculptor Frédéric Auguste Bartholdi and its metal framework was built by Gustave Eiffel. The statue was dedicated on October 28, 1886.
The Statue of Liberty is a figure of Libertas, a robed Roman liberty goddess. She holds a torch above her head with her right hand, and in her left hand carries a tabula ansata inscribed in Roman numerals with "JULY IV MDCCLXXVI" (July 4, 1776), the date of the U.S. Declaration of Independence. A broken chain lies at her feet as she walks forward. The statue became an icon of freedom and of the United States, a national park tourism destination, and is a welcoming sight to immigrants arriving from abroad.
Bartholdi was inspired by a French law professor and politician, Édouard René de Laboulaye, who is said to have commented in 1865 that any monument raised to U.S. independence would properly be a joint project of the French and U.S. peoples. Because of the post-war instability in France, work on the statue did not commence until the early 1870s. In 1875, Laboulaye proposed that the French finance the statue and the U.S. provide the site and build the pedestal. Bartholdi completed the head and the torch-bearing arm before the statue was fully designed, and these pieces were exhibited for publicity at international expositions.
The torch-bearing arm was displayed at the Centennial Exposition in Philadelphia in 1876, and in Madison Square Park in Manhattan from 1876 to 1882. Fundraising proved difficult, especially for the Americans, and by 1885 work on the pedestal was threatened by lack of funds. Publisher Joseph Pulitzer, of the New York World, started a drive for donations to finish the project and attracted more than 120,000contributors, most of whom gave less than a dollar. The statue was built in France, shipped overseas in crates, and assembled on the completed pedestal on what was then called Bedloe's Island. The statue's completion was marked by New York's first ticker-tape parade and a dedication ceremony presided over by President Grover Cleveland.
The statue was administered by the United States Lighthouse Board until 1901 and then by the Department of War; since 1933 it has been maintained by the National Park Service. Public access to the balcony around the torch has been barred for safety since 1916.
Design and construction process
Origin

According to the National Park Service, the idea of a monument presented by the French people to the United States was first proposed by Édouard René de Laboulaye, president of the French Anti-Slavery Society and a prominent and important political thinker of his time. The project is traced to a mid-1865 conversation between de Laboulaye, a staunch abolitionist, and Frédéric Bartholdi, a sculptor. In after-dinner conversation at his home near Versailles, Laboulaye, an ardent supporter of the Union in the American Civil War, is supposed to have said: "If a monument should rise in the United States, as a memorial to their independence, I should think it only natural if it were built by united effort—a common work of both our nations."[7]  The National Park Service, in a 2000 report, however, deemed this a legend traced to an 1885 fundraising pamphlet, and that the statue was most likely conceived in 1870.[8] In another essay on their website, the Park Service suggested that Laboulaye was minded to honor the Union victory and its consequences, "With the abolition of slavery and the Union's victory in the Civil War in 1865, Laboulaye's wishes of freedom and democracy were turning into a reality in the United States. In order to honor these achievements, Laboulaye proposed that a gift be built for the United States on behalf of France. Laboulaye hoped that by calling attention to the recent achievements of the United States, the French people would be inspired to call for their own democracy in the face of a repressive monarchy."[9]

According to sculptor Frédéric Auguste Bartholdi, who later recounted the story, Laboulaye's comment was not intended as a proposal, but it inspired Bartholdi.[7] Given the repressive nature of the regime of Napoleon III, Bartholdi took no immediate action on the idea except to discuss it with Laboulaye. Bartholdi was in any event busy with other possible projects; in the late 1860s, he approached Isma'il Pasha, Khedive of Egypt, with a plan to build Progress or Egypt Carrying the Light to Asia,[10] a huge lighthouse in the form of an ancient Egyptian female fellah or peasant, robed and holding a torch aloft, at the northern entrance to the Suez Canal in Port Said. Sketches and models were made of the proposed work, though it was never erected. There was a classical precedent for the Suez proposal, the Colossus of Rhodes: an ancient bronze statue of the Greek god of the sun, Helios. This statue is believed to have been over 100 feet (30m) high, and it similarly stood at a harbor entrance and carried a light to guide ships.[11] Both the khedive and Lesseps declined the proposed statue from Bartholdi, citing the expensive cost.[12] The Port Said Lighthouse was built instead, by François Coignet in 1869.

Any large project was further delayed by the Franco-Prussian War, in which Bartholdi served as a major of militia. In the war, Napoleon III was captured and deposed. Bartholdi's home province of Alsace was lost to the Prussians, and a more liberal republic was installed in France.[7] As Bartholdi had been planning a trip to the United States, he and Laboulaye decided the time was right to discuss the idea with influential Americans.[13] In June 1871, Bartholdi crossed the Atlantic, with letters of introduction signed by Laboulaye.[14]
Arriving at New York Harbor, Bartholdi focused on Bedloe's Island (now named Liberty Island) as a site for the statue, struck by the fact that vessels arriving in New York had to sail past it. He was delighted to learn that the island was owned by the United States government—it had been ceded by the New York State Legislature in 1800 for harbor defense. It was thus, as he put it in a letter to Laboulaye: "land common to all the states."[15] As well as meeting many influential New Yorkers, Bartholdi visited President Ulysses S. Grant, who assured him that it would not be difficult to obtain the site for the statue.[16] Bartholdi crossed the United States twice by rail, and met many Americans who he thought would be sympathetic to the project.[14] But he remained concerned that popular opinion on both sides of the Atlantic was insufficiently supportive of the proposal, and he and Laboulaye decided to wait before mounting a public campaign.[17]

Bartholdi had made a first model of his concept in 1870.[18] The son of a friend of Bartholdi's, U.S. artist John LaFarge, later maintained that Bartholdi made the first sketches for the statue during his U.S. visit at La Farge's Rhode Island studio. Bartholdi continued to develop the concept following his return to France.[18] He also worked on a number of sculptures designed to bolster French patriotism after the defeat by the Prussians. One of these was the Lion of Belfort, a monumental sculpture carved in sandstone below the fortress of Belfort, which during the war had resisted a Prussian siege for over three months. The defiant lion, 73 feet (22m) long and half that in height, displays an emotional quality characteristic of Romanticism, which Bartholdi would later bring to the Statue of Liberty.[19]
Design, style, and symbolism

Bartholdi and Laboulaye considered how best to express the idea of American liberty.[20] In early American history, two female figures were frequently used as cultural symbols of the nation.[21] One of these symbols, the personified Columbia, was seen as an embodiment of the United States in the manner that Britannia was identified with the United Kingdom and Marianne came to represent France. Columbia had supplanted the earlier figure of an Indian princess, which had come to be regarded as uncivilized and derogatory toward Americans.[21] The other significant female icon in American culture was a representation of Liberty, derived from Libertas, the goddess of freedom widely worshipped in ancient Rome, especially among emancipated slaves. A Liberty figure adorned most American coins of the time,[20] and representations of Liberty appeared in popular and civic art, including Thomas Crawford's Statue of Freedom (1863) atop the dome of the United States Capitol Building.[20]

Artists of the 18th and 19th centuries striving to evoke republican ideals commonly used representations of Libertas as an allegorical symbol.[20]  A figure of Liberty was also depicted on the Great Seal of France.[20]  However, Bartholdi and Laboulaye avoided an image of revolutionary liberty such as that depicted in Eugène Delacroix's famed Liberty Leading the People (1830). In this painting, which commemorates France's July Revolution, a half-clothed Liberty leads an armed mob over the bodies of the fallen.[21] Laboulaye had no sympathy for revolution, and so Bartholdi's figure would be fully dressed in flowing robes.[21] Instead of the impression of violence in the Delacroix work, Bartholdi wished to give the statue a peaceful appearance and chose a torch, representing progress, for the figure to hold.[22]
Crawford's statue was designed in the early 1850s. It was originally to be crowned with a pileus, the cap given to emancipated slaves in ancient Rome. Secretary of War Jefferson Davis, a Southerner who would later serve as President of the Confederate States of America, was concerned that the pileus would be taken as an abolitionist symbol. He ordered that it be changed to a helmet.[23]
Delacroix's figure wears a pileus,[21] and Bartholdi at first considered placing one on his figure as well. Instead, he used a diadem, or crown, to top its head.[24] In so doing, he avoided a reference to Marianne, who invariably wears a pileus.[25] The seven rays form a halo or aureole.[26] They evoke the sun, the seven seas, and the seven continents,[27] and represent another means, besides the torch, whereby Liberty enlightens the world.[22]
Bartholdi's early models were all similar in concept: a female figure in neoclassical style representing liberty, wearing a stola and pella (gown and cloak, common in depictions of Roman goddesses) and holding a torch aloft. According to popular accounts, the face was modeled after that of Charlotte Beysser Bartholdi, the sculptor's mother,[28] but Regis Huber, the curator of the Bartholdi Museum is on record as saying that this, as well as other similar speculations, have no basis in fact.[29] He designed the figure with a strong, uncomplicated silhouette, which would be set off well by its dramatic harbor placement and allow passengers on vessels entering New York Bay to experience a changing perspective on the statue as they proceeded toward Manhattan. He gave it bold classical contours and applied simplified modeling, reflecting the huge scale of the project and its solemn purpose.[22] Bartholdi wrote of his technique:
The surfaces should be broad and simple, defined by a bold and clear design, accentuated in the important places. The enlargement of the details or their multiplicity is to be feared. By exaggerating the forms, in order to render them more clearly visible, or by enriching them with details, we would destroy the proportion of the work. Finally, the model, like the design, should have a summarized character, such as one would give to a rapid sketch. Only it is necessary that this character should be the product of volition and study, and that the artist, concentrating his knowledge, should find the form and the line in its greatest simplicity.[30]

Bartholdi made alterations in the design as the project evolved. Bartholdi considered having Liberty hold a broken chain, but decided this would be too divisive in the days after the Civil War. The erected statue does stride over a broken chain, half-hidden by her robes and difficult to see from the ground.[24] Bartholdi was initially uncertain of what to place in Liberty's left hand; he settled on a tabula ansata,[31] used to evoke the concept of law.[32] Though Bartholdi greatly admired the United States Constitution, he chose to inscribe "JULY IV MDCCLXXVI" on the tablet, thus associating the date of the country's Declaration of Independence with the concept of liberty.[31]
Bartholdi interested his friend and mentor, architect Eugène Viollet-le-Duc, in the project.[29] As chief engineer,[29] Viollet-le-Duc designed a brick pier within the statue, to which the skin would be anchored.[33]
After consultations with the metalwork foundry Gaget, Gauthier & Co., Viollet-le-Duc chose the metal which would be used for the skin, copper sheets, and the method used to shape it, repoussé, in which the sheets were heated and then struck with wooden hammers.[29][34] An advantage of this choice was that the entire statue would be light for its volume, as the copper need be only 0.094 inches (2.4mm) thick. Bartholdi had decided on a height of just over 151 feet (46m) for the statue, double that of Italy's Sancarlone and the German statue of Arminius, both made with the same method.[35]
Announcement and early work
By 1875, France was enjoying improved political stability and a recovering postwar economy. Growing interest in the upcoming Centennial Exposition in Philadelphia led Laboulaye to decide it was time to seek public support.[36] In September 1875, he announced the project and the formation of the Franco-American Union as its fundraising arm. With the announcement, the statue was given a name, Liberty Enlightening the World.[37] The French would finance the statue; Americans would be expected to pay for the pedestal.[38] The announcement provoked a generally favorable reaction in France, though many Frenchmen resented the United States for not coming to their aid during the war with Prussia.[37] French monarchists opposed the statue, if for no other reason than it was proposed by the liberal Laboulaye, who had recently been elected a senator for life.[38] Laboulaye arranged events designed to appeal to the rich and powerful, including a special performance at the Paris Opera on April 25, 1876, that featured a new cantata by composer Charles Gounod. The piece was titled La Liberté éclairant le monde, the French version of the statue's announced name.[37]

Initially focused on the elites, the Union was successful in raising funds from across French society. Schoolchildren and ordinary citizens gave, as did 181French municipalities. Laboulaye's political allies supported the call, as did descendants of the French contingent in the American Revolutionary War. Less idealistically, contributions came from those who hoped for American support in the French attempt to build the Panama Canal. The copper may have come from multiple sources and some of it is said to have come from a mine in Visnes, Norway,[39] though this has not been conclusively determined after testing samples.[40] According to Cara Sutherland in her book on the statue for the Museum of the City of New York, 200,000 pounds (91,000kg) was needed to build the statue, and the French copper industrialist Eugène Secrétan donated 128,000 pounds (58,000kg) of copper.[41]
Although plans for the statue had not been finalized, Bartholdi moved forward with fabrication of the right arm, bearing the torch, and the head. Work began at the Gaget, Gauthier & Co. workshop.[42] In May 1876, Bartholdi traveled to the United States as a member of a French delegation to the Centennial Exhibition,[43] and arranged for a huge painting of the statue to be shown in New York as part of the Centennial festivities.[44] The arm did not arrive in Philadelphia until August; because of its late arrival, it was not listed in the exhibition catalogue, and while some reports correctly identified the work, others called it the "Colossal Arm" or "Bartholdi Electric Light". The exhibition grounds contained a number of monumental artworks to compete for fairgoers' interest, including an outsized fountain designed by Bartholdi.[45] Nevertheless, the arm proved popular in the exhibition's waning days, and visitors would climb up to the balcony of the torch to view the fairgrounds.[46] After the exhibition closed, the arm was transported to New York, where it remained on display in Madison Square Park for several years before it was returned to France to join the rest of the statue.[46]
During his second trip to the United States, Bartholdi addressed a number of groups about the project, and urged the formation of American committees of the Franco-American Union.[47] Committees to raise money to pay for the foundation and pedestal were formed in New York, Boston, and Philadelphia.[48] The New York group eventually took on most of the responsibility for American fundraising and is often referred to as the "American Committee".[49] One of its members was 19-year-old Theodore Roosevelt, the future governor of New York and president of the United States.[47] On March 3, 1877, on his final full day in office, President Grant signed a joint resolution that authorized the President to accept the statue when it was presented by France and to select a site for it. President Rutherford B. Hayes, who took office the following day, selected the Bedloe's Island site that Bartholdi had proposed.[50]
Construction in France

On his return to Paris in 1877, Bartholdi concentrated on completing the head, which was exhibited at the 1878 Paris World's Fair. Fundraising continued, with models of the statue put on sale. Tickets to view the construction activity at the Gaget, Gauthier & Co. workshop were also offered.[51] The French government authorized a lottery; among the prizes were valuable silver plate and a terracotta model of the statue. By the end of 1879, about 250,000francs had been raised.[52]
The head and arm had been built with assistance from Viollet-le-Duc, who fell ill in 1879. He soon died, leaving no indication of how he intended to transition from the copper skin to his proposed masonry pier.[53] The following year, Bartholdi was able to obtain the services of the innovative designer and builder Gustave Eiffel.[51] Eiffel and his structural engineer, Maurice Koechlin, decided to abandon the pier and instead build an iron truss tower. Eiffel opted not to use a completely rigid structure, which would force stresses to accumulate in the skin and lead eventually to cracking. A secondary skeleton was attached to the center pylon, then, to enable the statue to move slightly in the winds of New York Harbor and as the metal expanded on hot summer days, he loosely connected the support structure to the skin using flat iron bars[29] which culminated in a mesh of metal straps, known as "saddles", that were riveted to the skin, providing firm support. In a labor-intensive process, each saddle had to be crafted individually.[54][55] To prevent galvanic corrosion between the copper skin and the iron support structure, Eiffel insulated the skin with asbestos impregnated with shellac.[56]
Eiffel's design made the statue one of the earliest examples of curtain wall construction, in which the exterior of the structure is not load bearing, but is instead supported by an interior framework. He included two interior spiral staircases, to make it easier for visitors to reach the observation point in the crown.[57] Access to an observation platform surrounding the torch was also provided, but the narrowness of the arm allowed for only a single ladder, 40 feet (12m) long.[58] As the pylon tower arose, Eiffel and Bartholdi coordinated their work carefully so that completed segments of skin would fit exactly on the support structure.[59] The components of the pylon tower were built in the Eiffel factory in the nearby Parisian suburb of Levallois-Perret.[60]
The change in structural material from masonry to iron allowed Bartholdi to change his plans for the statue's assembly. He had originally expected to assemble the skin on-site as the masonry pier was built; instead he decided to build the statue in France and have it disassembled and transported to the United States for reassembly in place on Bedloe's Island.[61]
In a symbolic act, the first rivet placed into the skin, fixing a copper plate onto the statue's big toe, was driven by United States Ambassador to France Levi P. Morton.[62] The skin was not, however, crafted in exact sequence from low to high; work proceeded on a number of segments simultaneously in a manner often confusing to visitors.[63] Some work was performed by contractors—one of the fingers was made to Bartholdi's exacting specifications by a coppersmith in the southern French town of Montauban.[64] By 1882, the statue was complete up to the waist, an event Barthodi celebrated by inviting reporters to lunch on a platform built within the statue.[65] Laboulaye died in 1883. He was succeeded as chairman of the French committee by Ferdinand de Lesseps, builder of the Suez Canal. The completed statue was formally presented to Ambassador Morton at a ceremony in Paris on July 4, 1884, and de Lesseps announced that the French government had agreed to pay for its transport to New York.[66] The statue remained intact in Paris pending sufficient progress on the pedestal; by January 1885, this had occurred and the statue was disassembled and crated for its ocean voyage.[67]

The committees in the United States faced great difficulties in obtaining funds for the construction of the pedestal. The Panic of 1873 had led to an economic depression that persisted through much of the decade. The Liberty statue project was not the only such undertaking that had difficulty raising money: construction of the obelisk later known as the Washington Monument sometimes stalled for years; it would ultimately take over three-and-a-half decades to complete.[68] There was criticism both of Bartholdi's statue and of the fact that the gift required Americans to foot the bill for the pedestal. In the years following the Civil War, most Americans preferred realistic artworks depicting heroes and events from the nation's history, rather than allegorical works like the Liberty statue.[68] There was also a feeling that Americans should design American public works—the selection of Italian-born Constantino Brumidi to decorate the Capitol had provoked intense criticism, even though he was a naturalized U.S. citizen.[69] Harper's Weekly declared its wish that "M. Bartholdi and our French cousins had 'gone the whole figure' while they were about it, and given us statue and pedestal at once."[70] The New York Times stated that "no true patriot can countenance any such expenditures for bronze females in the present state of our finances."[71] Faced with these criticisms, the American committees took little action for several years.[71]
Design

The foundation of Bartholdi's statue was to be laid inside Fort Wood, a disused army base on Bedloe's Island constructed between 1807 and 1811. Since 1823, it had rarely been used, though during the Civil War, it had served as a recruiting station.[72] The fortifications of the structure were in the shape of an eleven-point star. The statue's foundation and pedestal were aligned so that it would face southeast, greeting ships entering the harbor from the Atlantic Ocean.[73]
In 1881, the New York committee commissioned Richard Morris Hunt to design the pedestal. Within months, Hunt submitted a detailed plan, indicating that he expected construction to take about nine months.[74] He proposed a pedestal 114 feet (35m) in height; faced with money problems, the committee reduced that to 89 feet (27m).[75]
Hunt's pedestal design contains elements of classical architecture, including Doric portals, as well as some elements influenced by Aztec architecture.[29] The large mass is fragmented with architectural detail, in order to focus attention on the statue.[75] In form, it is a truncated pyramid, 62 feet (19m) square at the base and 39.4 feet (12.0m) at the top. The four sides are identical in appearance. Above the door on each side, there are ten disks upon which Bartholdi proposed to place the coats of arms of the states (between 1876 and 1889, there were 38 U.S. states), although this was not done. Above that, a balcony was placed on each side, framed by pillars. Bartholdi placed an observation platform near the top of the pedestal, above which the statue itself rises.[76] According to author Louis Auchincloss, the pedestal "craggily evokes the power of an ancient Europe over which rises the dominating figure of the Statue of Liberty".[75] The committee hired former army General Charles Pomeroy Stone to oversee the construction work.[77] Construction on the 15-foot-deep (4.6m) foundation began in 1883, and the pedestal's cornerstone was laid in 1884.[74] In Hunt's original conception, the pedestal was to have been made of solid granite. Financial concerns again forced him to revise his plans; the final design called for poured concrete walls, up to 20 feet (6.1m) thick, faced with granite blocks.[78][79] This Stony Creek granite came from the Beattie Quarry in Branford, Connecticut.[80] The concrete mass was the largest poured to that time.[79]
Norwegian immigrant civil engineer Joachim Goschen Giæver designed the structural framework for the Statue of Liberty. His work involved design computations, detailed fabrication and construction drawings, and oversight of construction. In completing his engineering for the statue's frame, Giæver worked from drawings and sketches produced by Gustave Eiffel.[81]
Fundraising

Fundraising for the statue had begun in 1882. The committee organized a large number of money-raising events.[82] As part of one such effort, an auction of art and manuscripts, poet Emma Lazarus was asked to donate an original work. She initially declined, stating she could not write a poem about a statue. At the time, she was also involved in aiding refugees to New York who had fled anti-Semitic pogroms in eastern Europe. These refugees were forced to live in conditions that the wealthy Lazarus had never experienced. She saw a way to express her empathy for these refugees in terms of the statue.[83] The resulting sonnet, "The New Colossus", including the iconic lines "Give me your tired, your poor/Your huddled masses yearning to breathe free", is uniquely identified with the Statue of Liberty and is inscribed on a plaque in the museum in its base.[84]
Even with these efforts, fundraising lagged. Grover Cleveland, the governor of New York, vetoed a bill to provide $50,000 for the statue project in 1884. An attempt the next year to have Congress provide $100,000, sufficient to complete the project, also failed. The New York committee, with only $3,000 in the bank, suspended work on the pedestal. With the project in jeopardy, groups from other American cities, including Boston and Philadelphia, offered to pay the full cost of erecting the statue in return for relocating it.[85]
Joseph Pulitzer, publisher of the New York World, a New York newspaper, announced a drive to raise $100,000—the equivalent of $2.3million today.[86] Pulitzer pledged to print the name of every contributor, no matter how small the amount given.[87] The drive captured the imagination of New Yorkers, especially when Pulitzer began publishing the notes he received from contributors. "A young girl alone in the world" donated "60cents, the result of self denial."[88] One donor gave "five cents as a poor office boy's mite toward the Pedestal Fund." A group of children sent a dollar as "the money we saved to go to the circus with."[89] Another dollar was given by a "lonely and very aged woman."[88] Residents of a home for alcoholics in New York's rival city of Brooklyn—the cities would not merge until 1898—donated $15; other drinkers helped out through donation boxes in bars and saloons.[90] A kindergarten class in Davenport, Iowa, mailed the World a gift of $1.35.[88] As the donations flooded in, the committee resumed work on the pedestal.[91]
Construction
On June 17, 1885, the French steamer Isère, arrived in New York with the crates holding the disassembled statue on board. New Yorkers displayed their new-found enthusiasm for the statue. Two hundred thousand people lined the docks and hundreds of boats put to sea to welcome the ship.[92][93] After five months of daily calls to donate to the statue fund, on August 11, 1885, the World announced that $102,000 had been raised from 120,000donors, and that 80 percent of the total had been received in sums of less than one dollar.[94]
Even with the success of the fund drive, the pedestal was not completed until April 1886. Immediately thereafter, reassembly of the statue began. Eiffel's iron framework was anchored to steel I-beams within the concrete pedestal and assembled.[95] Once this was done, the sections of skin were carefully attached.[96] Due to the width of the pedestal, it was not possible to erect scaffolding, and workers dangled from ropes while installing the skin sections. Nevertheless, no one died during the construction.[97] Bartholdi had planned to put floodlights on the torch's balcony to illuminate it; a week before the dedication, the Army Corps of Engineers vetoed the proposal, fearing that ships' pilots passing the statue would be blinded. Instead, Bartholdi cut portholes in the torch—which was covered with gold leaf—and placed the lights inside them.[98] A power plant was installed on the island to light the torch and for other electrical needs.[99] After the skin was completed, renowned landscape architect Frederick Law Olmsted, co-designer of New York's Central Park and Brooklyn's Prospect Park, supervised a cleanup of Bedloe's Island in anticipation of the dedication.[100]
Dedication

A ceremony of dedication was held on the afternoon of October 28, 1886. President Grover Cleveland, the former New York governor, presided over the event.[101] On the morning of the dedication, a parade was held in New York City; estimates of the number of people who watched it ranged from several hundred thousand to a million. President Cleveland headed the procession, then stood in the reviewing stand to see bands and marchers from across America. General Stone was the grand marshal of the parade. The route began at Madison Square, once the venue for the arm, and proceeded to the Battery at the southern tip of Manhattan by way of Fifth Avenue and Broadway, with a slight detour so the parade could pass in front of the World building on Park Row. As the parade passed the New York Stock Exchange, traders threw ticker tape from the windows, beginning the New York tradition of the ticker-tape parade.[102]
A nautical parade began at 12:45p.m., and President Cleveland embarked on a yacht that took him across the harbor to Bedloe's Island for the dedication.[103] De Lesseps made the first speech, on behalf of the French committee, followed by the chairman of the New York committee, Senator William M. Evarts. A French flag draped across the statue's face was to be lowered to unveil the statue at the close of Evarts's speech, but Bartholdi mistook a pause as the conclusion and let the flag fall prematurely. The ensuing cheers put an end to Evarts's address.[102] President Cleveland spoke next, stating that the statue's "stream of light shall pierce the darkness of ignorance and man's oppression until Liberty enlightens the world".[104] Bartholdi, observed near the dais, was called upon to speak, but he declined. Orator Chauncey M. Depew concluded the speechmaking with a lengthy address.[105]
No members of the general public were permitted on the island during the ceremonies, which were reserved entirely for dignitaries. The only females granted access were Bartholdi's wife and de Lesseps's granddaughter; officials stated that they feared women might be injured in the crush of people. The restriction offended area suffragists, who chartered a boat and got as close as they could to the island. The group's leaders made speeches applauding the embodiment of Liberty as a woman and advocating women's right to vote.[104] A scheduled fireworks display was postponed until November 1 because of poor weather.[106]
Shortly after the dedication, The Cleveland Gazette, an African American newspaper, suggested that the statue's torch not be lit until the United States became a free nation "in reality":
"Liberty enlightening the world," indeed! The expression makes us sick. This government is a howling farce. It can not or rather does not protect its citizens within its own borders. Shove the Bartholdi statue, torch and all, into the ocean until the "liberty" of this country is such as to make it possible for an inoffensive and industrious colored man to earn a respectable living for himself and family, without being ku-kluxed, perhaps murdered, his daughter and wife outraged, and his property destroyed. The idea of the "liberty" of this country "enlightening the world," or even Patagonia, is ridiculous in the extreme.[107]

After dedication
Lighthouse Board and War Department (1886–1933)

When the torch was illuminated on the evening of the statue's dedication, it produced only a faint gleam, barely visible from Manhattan. The World characterized it as "more like a glowworm than a beacon."[99] Bartholdi suggested gilding the statue to increase its ability to reflect light, but this proved too expensive. The United States Lighthouse Board took over the Statue of Liberty in 1887 and pledged to install equipment to enhance the torch's effect; in spite of its efforts, the statue remained virtually invisible at night. When Bartholdi returned to the United States in 1893, he made additional suggestions, all of which proved ineffective. He did successfully lobby for improved lighting within the statue, allowing visitors to better appreciate Eiffel's design.[99] In 1901, President Theodore Roosevelt, once a member of the New York committee, ordered the statue's transfer to the War Department, as it had proved useless as a lighthouse.[108] A unit of the Army Signal Corps was stationed on Bedloe's Island until 1923, after which military police remained there while the island was under military jurisdiction.[109]
The statue rapidly became a landmark. Many immigrants who entered through New York saw it as a welcoming sight. Oral histories of immigrants record their feelings of exhilaration on first viewing the Statue of Liberty. One immigrant who arrived from Greece recalled:
I saw the Statue of Liberty. And I said to myself, "Lady, you're such a beautiful![sic] You opened your arms and you get all the foreigners here. Give me a chance to prove that I am worth it, to do something, to be someone in America." And always that statue was on my mind.[110]

Originally, the statue was a dull copper color, but shortly after 1900 a green patina, also called verdigris, caused by the oxidation of the copper skin, began to spread. As early as 1902 it was mentioned in the press; by 1906 it had entirely covered the statue.[111] Believing that the patina was evidence of corrosion, Congress authorized US$62,800(equivalent to $1,751,000 in 2018) for various repairs, and to paint the statue both inside and out.[112] There was considerable public protest against the proposed exterior painting.[113] The Army Corps of Engineers studied the patina for any ill effects to the statue and concluded that it protected the skin, "softened the outlines of the Statue and made it beautiful."[114] The statue was painted only on the inside. The Corps of Engineers also installed an elevator to take visitors from the base to the top of the pedestal.[114]
On July 30, 1916, during World War I, German saboteurs set off a disastrous explosion on the Black Tom peninsula in Jersey City, New Jersey, in what is now part of Liberty State Park, close to Bedloe's Island. Carloads of dynamite and other explosives that were being sent to Britain and France for their war efforts were detonated, and seven people were killed. The statue sustained minor damage, mostly to the torch-bearing right arm, and was closed for ten days. The cost to repair the statue and buildings on the island was about US$100,000(equivalent to about $2,300,000 in 2018). The narrow ascent to the torch was closed for public-safety reasons, and it has remained closed ever since.[105]
That same year, Ralph Pulitzer, who had succeeded his father Joseph as publisher of the World, began a drive to raise US$30,000(equivalent to $691,000 in 2018) for an exterior lighting system to illuminate the statue at night. He claimed over 80,000 contributors, but failed to reach the goal. The difference was quietly made up by a gift from a wealthy donor—a fact that was not revealed until 1936. An underwater power cable brought electricity from the mainland and floodlights were placed along the walls of Fort Wood. Gutzon Borglum, who later sculpted Mount Rushmore, redesigned the torch, replacing much of the original copper with stained glass. On December 2, 1916, President Woodrow Wilson pressed the telegraph key that turned on the lights, successfully illuminating the statue.[115]
After the United States entered World War I in 1917, images of the statue were heavily used in both recruitment posters and the Liberty Bond drives that urged American citizens to support the war financially. This impressed upon the public the war's stated purpose—to secure liberty—and served as a reminder that embattled France had given the United States the statue.[116]
In 1924, President Calvin Coolidge used his authority under the Antiquities Act to declare the statue a National Monument.[108] The only successful suicide in the statue's history occurred five years later, when a man climbed out of one of the windows in the crown and jumped to his death, glancing off the statue's breast and landing on the base.[117]
Early National Park Service years (1933–1982)

In 1933, President Franklin Roosevelt ordered the statue to be transferred to the National Park Service (NPS). In 1937, the NPS gained jurisdiction over the rest of Bedloe's Island.[108] With the Army's departure, the NPS began to transform the island into a park.[118] The Works Progress Administration (WPA) demolished most of the old buildings, regraded and reseeded the eastern end of the island, and built granite steps for a new public entrance to the statue from its rear. The WPA also carried out restoration work within the statue, temporarily removing the rays from the statue's halo so their rusted supports could be replaced. Rusted cast-iron steps in the pedestal were replaced with new ones made of reinforced concrete;[119] the upper parts of the stairways within the statue were replaced, as well. Copper sheathing was installed to prevent further damage from rainwater that had been seeping into the pedestal.[120] The statue was closed to the public from May until December 1938.[119]
During World War II, the statue remained open to visitors, although it was not illuminated at night due to wartime blackouts. It was lit briefly on December 31, 1943, and on D-Day, June 6, 1944, when its lights flashed "dot-dot-dot-dash", the Morse code for V, for victory. New, powerful lighting was installed in 1944–1945, and beginning on V-E Day, the statue was once again illuminated after sunset. The lighting was for only a few hours each evening, and it was not until 1957 that the statue was illuminated every night, all night.[121] In 1946, the interior of the statue within reach of visitors was coated with a special plastic so that graffiti could be washed away.[120]
In 1956, an Act of Congress officially renamed Bedloe's Island as Liberty Island, a change advocated by Bartholdi generations earlier. The act also mentioned the efforts to found an American Museum of Immigration on the island, which backers took as federal approval of the project, though the government was slow to grant funds for it.[122] Nearby Ellis Island was made part of the Statue of Liberty National Monument by proclamation of President Lyndon Johnson in 1965.[108] In 1972, the immigration museum, in the statue's base, was finally opened in a ceremony led by President Richard Nixon. The museum's backers never provided it with an endowment to secure its future and it closed in 1991 after the opening of an immigration museum on Ellis Island.[95]

In 1970, Ivy Bottini led a demonstration at the statue where she and others from the National Organization for Women's New York chapter draped an enormous banner over a railing which read "WOMEN OF THE WORLD UNITE!"[123][124]
Beginning December 26, 1971, 15 anti-Vietnam War veterans occupied the statue, flying a US flag upside down from her crown. They left December 28 following a Federal Court order.[125] The statue was also several times taken over briefly by demonstrators publicizing causes such as Puerto Rican independence, opposition to abortion, and opposition to US intervention in Grenada.  Demonstrations with the permission of the Park Service included a Gay Pride Parade rally and the annual Captive Baltic Nations rally.[126]
A powerful new lighting system was installed in advance of the American Bicentennial in 1976. The statue was the focal point for Operation Sail, a regatta of tall ships from all over the world that entered New York Harbor on July 4, 1976, and sailed around Liberty Island.[127] The day concluded with a spectacular display of fireworks near the statue.[128]
Renovation and rededication (1982–2000)

The statue was examined in great detail by French and American engineers as part of the planning for its centennial in 1986.[129] In 1982, it was announced that the statue was in need of considerable restoration. Careful study had revealed that the right arm had been improperly attached to the main structure. It was swaying more and more when strong winds blew and there was a significant risk of structural failure. In addition, the head had been installed 2 feet (0.61m) off center, and one of the rays was wearing a hole in the right arm when the statue moved in the wind. The armature structure was badly corroded, and about two percent of the exterior plates needed to be replaced.[130] Although problems with the armature had been recognized as early as 1936, when cast iron replacements for some of the bars had been installed, much of the corrosion had been hidden by layers of paint applied over the years.[131]
In May 1982, President Ronald Reagan announced the formation of the Statue of Liberty–Ellis Island Centennial Commission, led by Chrysler Corporation chair Lee Iacocca, to raise the funds needed to complete the work.[132] Through its fundraising arm, the Statue of Liberty–Ellis Island Foundation, Inc., the group raised more than $350million in donations.[133] The Statue of Liberty was one of the earliest beneficiaries of a cause marketing campaign. A 1983 promotion advertised that for each purchase made with an American Express card, the company would contribute one cent to the renovation of the statue. The campaign generated contributions of $1.7million to the restoration project.[134]
In 1984, the statue was closed to the public for the duration of the renovation. Workers erected the world's largest free-standing scaffold,[29] which obscured the statue from view. Liquid nitrogen was used to remove layers of paint that had been applied to the interior of the copper skin over decades, leaving two layers of coal tar, originally applied to plug leaks and prevent corrosion. Blasting with baking soda powder removed the tar without further damaging the copper.[135] The restorers' work was hampered by the asbestos-based substance that Bartholdi had used—ineffectively, as inspections showed—to prevent galvanic corrosion. Workers within the statue had to wear protective gear, dubbed "moon suits", with self-contained breathing circuits.[136] Larger holes in the copper skin were repaired, and new copper was added where necessary.[137] The replacement skin was taken from a copper rooftop at Bell Labs, which had a patina that closely resembled the statue's; in exchange, the laboratory was provided some of the old copper skin for testing.[138] The torch, found to have been leaking water since the 1916 alterations, was replaced with an exact replica of Bartholdi's unaltered torch.[139] Consideration was given to replacing the arm and shoulder; the National Park Service insisted that they be repaired instead.[140] The original torch was removed and replaced in 1986 with the current one, whose flame is covered in 24-karat gold.[32] The torch reflects the sun's rays in daytime and is lighted by floodlights at night.[32]

The entire puddled iron armature designed by Gustave Eiffel was replaced. Low-carbon corrosion-resistant stainless steel bars that now hold the staples next to the skin are made of Ferralium, an alloy that bends slightly and returns to its original shape as the statue moves.[141] To prevent the ray and arm making contact, the ray was realigned by several degrees.[142] The lighting was again replaced—night-time illumination subsequently came from metal-halide lamps that send beams of light to particular parts of the pedestal or statue, showing off various details.[143] Access to the pedestal, which had been through a nondescript entrance built in the 1960s, was renovated to create a wide opening framed by a set of monumental bronze doors with designs symbolic of the renovation.[144] A modern elevator was installed, allowing handicapped access to the observation area of the pedestal.[145] An emergency elevator was installed within the statue, reaching up to the level of the shoulder.[146]
July 3–6, 1986, was designated "Liberty Weekend", marking the centennial of the statue and its reopening. President Reagan presided over the rededication, with French President François Mitterrand in attendance. July 4 saw a reprise of Operation Sail,[147] and the statue was reopened to the public on July 5.[148] In Reagan's dedication speech, he stated, "We are the keepers of the flame of liberty; we hold it high for the world to see."[147]
Closures and reopenings (2001–present)

Following the September 11 attacks, the statue and Liberty Island were immediately closed to the public. The island reopened at the end of 2001, while the pedestal and statue remained off-limits. The pedestal reopened in August 2004,[148] but the National Park Service announced that visitors could not safely be given access to the statue due to the difficulty of evacuation in an emergency. The Park Service adhered to that position through the remainder of the Bush administration.[149] New York Congressman Anthony Weiner made the statue's reopening a personal crusade.[150] On May 17, 2009, President Barack Obama's Secretary of the Interior, Ken Salazar, announced that as a "special gift" to America, the statue would be reopened to the public as of July 4, but that only a limited number of people would be permitted to ascend to the crown each day.[149]
The statue, including the pedestal and base, closed on October 29, 2011, for installation of new elevators and staircases and to bring other facilities, such as restrooms, up to code. The statue was reopened on October 28, 2012,[1][151][152]  only to close again a day later due to Hurricane Sandy.[153]  Although the storm did not harm the statue, it destroyed some of the infrastructure on both Liberty Island and Ellis Island,  severely damaging the dock used by the ferries bearing visitors to the statue.  On November 8, 2012, a Park Service spokesperson announced that both islands would remain closed for an indefinite period for repairs to be done.[154]  Due to lack of electricity on Liberty Island, a generator was installed to power temporary floodlights to illuminate the statue at night. The superintendent of Statue of Liberty National Monument, David Luchsinger, whose home on the island was severely damaged, stated that it would be "optimistically... months" before the island was reopened to the public.[155] The statue and Liberty Island reopened to the public on July 4, 2013.[156] Ellis Island remained closed for repairs for several more months but reopened in late October 2013.[157] For part of October 2013, Liberty Island was closed to the public due to the United States federal government shutdown of 2013, along with other federally funded museums, parks, monuments, construction projects and buildings.[158] The statue and Liberty Island were briefly closed on July 4, 2018, due to a protester against American immigration policy climbing onto the statue.[159]

On October 7, 2016, construction started on a new Statue of Liberty museum on Liberty Island. The new $70 million, 26,000-square-foot (2,400m2) museum will be able to accommodate all of the island's visitors when it opens in 2019, as opposed to the current museum, which only 20% of the island's visitors can visit.[160] The museum, designed by FXFOWLE Architects, will integrate with the parkland around it.[161][162] Von Fürstenberg heads the fundraising for the museum, and the project had garnered more than $40 million in fundraising as of groundbreaking.[161]
Access and attributes
Location and tourism

The statue is situated in Upper New York Bay on Liberty Island south of Ellis Island,  which together comprise the Statue of Liberty National Monument. Both islands were ceded by New York to the federal government in 1800.[163] As agreed in an 1834 compact between New York and New Jersey that set the state border at the bay's midpoint, the original islands remain New York territory though located on the New Jersey side of the state line. Liberty Island is one of the islands that are part of the borough of Manhattan in New York. Land created by reclamation added to the 2.3-acre (0.93ha) original island at Ellis Island is New Jersey territory.[164]
No charge is made for entrance to the national monument, but there is a cost for the ferry service that all visitors must use, as private boats may not dock at the island. A concession was granted in 2007 to Statue Cruises to operate the transportation and ticketing facilities, replacing Circle Line, which had operated the service since 1953.[165]
The ferries, which depart from Liberty State Park in Jersey City and Battery Park in Lower Manhattan, also stop at Ellis Island when it is open to the public, making a combined trip possible.[166] All ferry riders are subject to security screening, similar to airport procedures, prior to boarding.[167] Visitors intending to enter the statue's base and pedestal must obtain a complimentary museum/pedestal ticket along with their ferry ticket.[168] Those wishing to climb the staircase within the statue to the crown purchase a special ticket, which may be reserved up to a year in advance. A total of 240 people per day are permitted to ascend: ten per group, three groups per hour. Climbers may bring only medication and cameras—lockers are provided for other items—and must undergo a second security screening.[169]
Inscriptions, plaques, and dedications

There are several plaques and dedicatory tablets on or near the Statue of Liberty.
A plaque on the copper just under the figure in front declares that it is a colossal statue representing Liberty, designed by Bartholdi and built by the Paris firm of Gaget, Gauthier et Cie (Cie is the French abbreviation analogous to Co.). [170]
A presentation tablet, also bearing Bartholdi's name, declares the statue is a gift from the people of the Republic of France that honors "the Alliance of the two Nations in achieving the Independence of the United States of America and attests their abiding friendship."[170]
A tablet placed by the American Committee commemorates the fundraising done to build the pedestal.[170]
The cornerstone bears a plaque placed by the Freemasons.[170]
In 1903, a bronze tablet that bears the text of Emma Lazarus's sonnet, "The New Colossus" (1883), was presented by friends of the poet. Until the 1986 renovation, it was mounted inside the pedestal; today it resides in the Statue of Liberty Museum, in the base.[170]
"The New Colossus" tablet is accompanied by a tablet given by the Emma Lazarus Commemorative Committee in 1977, celebrating the poet's life.[170]
A group of statues stands at the western end of the island, honoring those closely associated with the Statue of Liberty. Two Americans—Pulitzer and Lazarus—and three Frenchmen—Bartholdi, Eiffel, and Laboulaye—are depicted. They are the work of Maryland sculptor Phillip Ratner.[171]
UNESCO World Heritage Site
In 1984, the Statue of Liberty was designated a UNESCO World Heritage Site. The UNESCO "Statement of Significance" describes the statue as a "masterpiece of the human spirit" that "endures as a highly potent symbol—inspiring contemplation, debate and protest—of ideals such as liberty, peace, human rights, abolition of slavery, democracy and opportunity."[172]
Physical characteristics

Depictions

Hundreds of replicas of the Statue of Liberty are displayed worldwide.[173] A smaller version of the statue, one-fourth the height of the original, was given by the American community in Paris to that city. It now stands on the Île aux Cygnes, facing west toward her larger sister.[173] A replica 30 feet (9.1m) tall stood atop the Liberty Warehouse on West 64thStreet in Manhattan for many years;[173] it now resides at the Brooklyn Museum.[174] In a patriotic tribute, the Boy Scouts of America, as part of their Strengthen the Arm of Liberty campaign in 1949–1952, donated about two hundred replicas of the statue, made of stamped copper and 100 inches (2.5m) in height, to states and municipalities across the United States.[175] Though not a true replica, the statue known as the Goddess of Democracy temporarily erected during the Tiananmen Square protests of 1989 was similarly inspired by French democratic traditions—the sculptors took care to avoid a direct imitation of the Statue of Liberty.[176] Among other recreations of New York City structures, a replica of the statue is part of the exterior of the New York-New York Hotel and Casino in Las Vegas.[177]

As an American icon, the Statue of Liberty has been depicted on the country's coinage and stamps. It appeared on commemorative coins issued to mark its 1986 centennial, and on New York's 2001 entry in the state quarters series.[178] An image of the statue was chosen for the American Eagle platinum bullion coins in 1997, and it was placed on the reverse, or tails, side of the Presidential Dollar series of circulating coins.[27] Two images of the statue's torch appear on the current ten-dollar bill.[179] The statue's intended photographic depiction on a 2010 forever stamp proved instead to be of the replica at the Las Vegas casino.[180]
Depictions of the statue have been used by many regional institutions. Between 1986[181] and 2000,[182] New York State issued license plates with an outline of the statue.[181][182] The Women's National Basketball Association's New York Liberty use both the statue's name and its image in their logo, in which the torch's flame doubles as a basketball.[183] The New York Rangers of the National Hockey League depicted the statue's head on their third jersey, beginning in 1997.[184] The National Collegiate Athletic Association's 1996 Men's Basketball Final Four, played at New Jersey's Meadowlands Sports Complex, featured the statue in its logo.[185]  The Libertarian Party of the United States uses the statue in its emblem.[186]
The statue is a frequent subject in popular culture. In music, it has been evoked to indicate support for American policies, as in Toby Keith's song "Courtesy of the Red, White and Blue (The Angry American)", and in opposition, appearing on the cover of the Dead Kennedys' album Bedtime for Democracy, which protested the Reagan administration.[187] In film, the torch is the setting for the climax of director Alfred Hitchcock's 1942 movie Saboteur.[188] The statue makes one of its most famous cinematic appearances in the 1968 picture Planet of the Apes, in which it is seen half-buried in sand.[187][189] It is knocked over in the science-fiction film Independence Day[190] and in Cloverfield the head is ripped off.[191] In Jack Finney's time-travel novel Time and Again, the right arm of the statue, on display in the early 1880s in Madison Square Park, plays a crucial role.[192] Robert Holdstock, consulting editor of The Encyclopedia of Science Fiction, wondered in 1979:
Where would science fiction be without the Statue of Liberty? For decades it has towered or crumbled above the wastelands of deserted [E]arth—giants have uprooted it, aliens have found it curious... the symbol of Liberty, of optimism, has become a symbol of science fiction's pessimistic view of the future.[193]

See also

List of the tallest statues in the United States
Place des États-Unis, in Paris, France
The Statue of Liberty, 1985 Ken Burns documentary film
Statues and sculptures in New York City
List of statues by height

Bibliography

 – many historical photographs
 at Structurae
Historic American Engineering Record (HAER) No.NY-138, "", 404photos, 59color transparencies, 41measured drawings, 10data pages, 33photo caption pages
HAER No.NY-138-A, "", 6photos, 6measured drawings, 1photo caption page
HAER No.NY-138-B, "", 12photos, 6measured drawings, 1photo caption page
, BBC Radio 4 discussion with Robert Gildea, Kathleen Burk & John Keane (In Our Time, February 14, 2008)

How much copper was used to make the Statue of Liberty?


In electrical power generation, the distinct ways of generating electricity incur significantly different costs. Calculations of these costs can be made at the point of connection to a load or to the electricity grid. The cost is typically given per kilowatt-hour or megawatt-hour. It includes the initial capital, discount rate, as well as the costs of continuous operation, fuel, and maintenance. This type of calculation assists policymakers, researchers and others to guide discussions and decision making.
The levelized cost of energy (LCOE) is a measure of a power source that allows comparison of different methods of electricity generation on a consistent basis. It is an economic assessment of the average total cost to build and operate a power-generating asset over its lifetime divided by the total energy output of the asset over that lifetime. The LCOE can also be regarded as the average minimum price at which electricity must be sold in order to break-even over the lifetime of the project.
Cost factors
While calculating costs, several internal cost factors have to be considered.[1] Note the use of "costs," which is not the actual selling price, since this can be affected by a variety of factors such as subsidies and taxes:
Capital costs (including waste disposal and decommissioning costs for nuclear energy) – tend to be low for fossil fuel power stations; high for wind turbines, solar PV (photovoltaics); very high for waste to energy, wave and tidal, solar thermal, and nuclear.
Fuel costs – high for fossil fuel and biomass sources, low for nuclear, and zero for many renewables. Fuel costs can vary somewhat unpredictably over the life of the generating equipment, due to political and other factors.
Factors such as the costs of waste (and associated issues) and different insurance costs are not included in the following: Works power, own use or parasitic load – that is, the portion of generated power actually used to run the station's pumps and fans has to be allowed for.
To evaluate the total cost of production of electricity, the streams of costs are converted to a net present value using the time value of money. These costs are all brought together using discounted cash flow.[2][3]
Levelized cost of electricity
The levelized cost of electricity (LCOE), also known as Levelized Energy Cost (LEC), is the net present value of the unit-cost of electricity over the lifetime of a generating asset. It is often taken as a proxy for the average price that the generating asset must receive in a market to break even over its lifetime. It is a first-order economic assessment of the cost competitiveness of an electricity-generating system that incorporates all costs over its lifetime: initial investment, operations and maintenance, cost of fuel, cost of capital.
The levelized cost is that value for which an equal-valued fixed revenue delivered over the life of the asset's generating profile would cause the project to break even. This can be roughly calculated as the net present value of all costs over the lifetime of the asset divided by the total electrical energy output of the asset.[4]
The levelized cost of electricity (LCOE) is given by:

L
C
O
E

=

sum of costs over lifetime
sum of electrical energy produced over lifetime

=

∑

t
=
1

n

I

t

+

M

t

+

F

t

(

1
+
r

)

t

∑

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=
1

n

E

t

(

1
+
r

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t

{\displaystyle \mathrm {LCOE} ={\frac {\text{sum of costs over lifetime}}{\text{sum of electrical energy produced over lifetime}}}={\frac {\sum _{t=1}^{n}{\frac {I_{t}+M_{t}+F_{t}}{\left({1+r}\right)^{t}}}}{\sum _{t=1}^{n}{\frac {E_{t}}{\left({1+r}\right)^{t}}}}}}

It:investment expenditures in the year tMt:operations and maintenance expenditures in the year tFt:fuel expenditures in the year tEt:electrical energy generated in the year tr:discount raten:expected lifetime of system or power station
Note: Some caution must be taken when using formulas for the levelized cost, as they often embody unseen assumptions, neglect effects like taxes, and may be specified in real or nominal levelized cost. For example, other versions of the above formula do not discount the electricity stream.
Typically the LCOE is calculated over the design lifetime of a plant, which is usually 20 to 40 years, and given in the units of currency per kilowatt-hour or megawatt-day, for example AUD/kWh or EUR/kWh or per megawatt-hour, for example AUD/MWh (as tabulated below).[5] However, care should be taken in comparing different LCOE studies and the sources of the information as the LCOE for a given energy source is highly dependent on the assumptions, financing terms and technological deployment analyzed.[6] In particular, assumption of capacity factor has significant impact on the calculation of LCOE. Thus, a key requirement for the analysis is a clear statement of the applicability of the analysis based on justified assumptions.[6]
Many scholars, such as Paul Joskow, have described limits to the "levelized cost of electricity" metric for comparing new generating sources. In particular, LCOE ignores time effects associated with matching production to demand. This happens at two levels:
Dispatchability, the ability of a generating system to come online, go offline, or ramp up or down, quickly as demand swings.
The extent to which the availability profile matches or conflicts with the market demand profile.
Thermally lethargic technologies like coal and nuclear are physically incapable of fast ramping. Capital intensive technologies such as wind, solar, and nuclear are economically disadvantaged unless generating at maximum availability since the LCOE is nearly all sunk-cost capital investment. Intermittent power sources, such as wind and solar, may incur extra costs associated with needing to have storage or backup generation available.[7] At the same time, intermittent sources can be competitive if they are available to produce when demand and prices are highest, such as solar during summertime mid-day peaks seen in hot countries where air conditioning is a major consumer.[6] Despite these time limitations, leveling costs is often a necessary prerequisite for making comparisons on an equal footing before demand profiles are considered, and the levelized-cost metric is widely used for comparing technologies at the margin, where grid implications of new generation can be neglected.
Another limitation of the LCOE metric is the influence of energy efficiency and conservation (EEC).[8]
EEC has caused the electricity demand of many countries to remain flat or decline. Considering only the LCOE for utility scale plants will tend to maximise generation and risks overestimating required generation due to efficiency, thus "lowballing" their LCOE. For solar systems installed at the point of end use, it is more economical to invest in EEC first, then solar (resulting in a smaller required solar system than what would be needed without the EEC measures). However, designing a solar system on the basis of LCOE would cause the smaller system LCOE to increase (as the energy generation [measured in kWh] drops faster than the system cost [$]). The whole of system life cycle cost should be considered, not just the LCOE of the energy source.[8] LCOE is not as relevant to end-users than other financial considerations such as income, cashflow, mortgage, leases, rent, and electricity bills.[8] Comparing solar investments in relation to these can make it easier for end-users to make a decision, or using cost-benefit calculations "and/or an asset’s capacity value or contribution to peak on a system or circuit level".[8]
Avoided cost
The US Energy Information Administration has recommended that levelized costs of non-dispatchable sources such as wind or solar may be better compared to the avoided energy cost rather than to the LCOE of dispatchable sources such as fossil fuels or geothermal. This is because introduction of fluctuating power sources may or may not avoid capital and maintenance costs of backup dispatchable sources. Levelized Avoided Cost of Energy (LACE) is the avoided costs from other sources divided by the annual yearly output of the non-dispatchable source. However, the avoided cost is much harder to calculate accurately.[9][10]
Marginal cost of electricity
A more accurate economic assessment might be the marginal cost of electricity. This value works by comparing the added system cost of increasing electricity generation from one source versus that from other sources of electricity generation (see Merit Order).
[11]
External costs of energy sources

Typically pricing of electricity from various energy sources may not include all external costs – that is, the costs indirectly borne by society as a whole as a consequence of using that energy source.[12] These may include enabling costs, environmental impacts, usage lifespans, energy storage, recycling costs, or beyond-insurance accident effects.
The US Energy Information Administration predicts that coal and gas are set to be continually used to deliver the majority of the world's electricity.[13] This is expected to result in the evacuation of millions of homes in low-lying areas, and an annual cost of hundreds of billions of dollars' worth of property damage.[14][15][16][17][18][19][20]
Furthermore, with a number of island nations becoming slowly submerged underwater due to rising sea levels,[21] massive international climate litigation lawsuits against fossil fuel users are currently beginning in the International Court of Justice.[22][23]
An EU funded research study known as ExternE, or Externalities of Energy, undertaken over the period of 1995 to 2005 found that the cost of producing electricity from coal or oil would double over its present value, and the cost of electricity production from gas would increase by 30% if external costs such as damage to the environment and to human health, from the particulate matter, nitrogen oxides, chromium VI, river water alkalinity, mercury poisoning and arsenic emissions produced by these sources, were taken into account. It was estimated in the study that these external, downstream, fossil fuel costs amount up to 1%–2% of the EU’s entire Gross Domestic Product (GDP), and this was before the external cost of global warming from these sources was even included.[24][25] Coal has the highest external cost in the EU, and global warming is the largest part of that cost.[12]
A means to address a part of the external costs of fossil fuel generation is carbon pricing — the method most favored by economics for reducing global-warming emissions. Carbon pricing charges those who emit carbon dioxide (CO2) for their emissions. That charge, called a 'carbon price', is the amount that must be paid for the right to emit one tonne of CO2 into the atmosphere.[26] Carbon pricing usually takes the form of a carbon tax or a requirement to purchase permits to emit (also called "allowances").
Depending on the assumptions of possible accidents and their probabilites external costs for nuclear power vary significantly and can reach between 0.2 and 200 ct/kWh.[27] Furthermore, nuclear power is working under an insurance framework that limits or structures accident liabilities in accordance with the Paris convention on nuclear third-party liability, the Brussels supplementary convention, and the Vienna convention on civil liability for nuclear damage[28] and in the U.S. the Price-Anderson Act. It is often argued that this potential shortfall in liability represents an external cost not included in the cost of nuclear electricity; but the cost is small, amounting to about 0.1% of the levelized cost of electricity, according to a CBO study.[29]
These beyond-insurance costs for worst-case scenarios are not unique to nuclear power, as hydroelectric power plants are similarly not fully insured against a catastrophic event such as the Banqiao Dam disaster, where 11 million people lost their homes and from 30,000 to 200,000 people died, or large dam failures in general. As private insurers base dam insurance premiums on limited scenarios, major disaster insurance in this sector is likewise provided by the state.[30]
Because externalities are diffuse in their effect, external costs can not be measured directly, but must be estimated. One approach estimate external costs of environmental impact of electricity is the Methodological Convention of Federal Environment Agency of Germany. That method arrives at external costs of electricity from lignite at 10.75 Eurocent/kWh, from hard coal 8.94 Eurocent/kWh, from natural gas 4.91 Eurocent/kWh, from photovoltaic 1.18 Eurocent/kWh, from wind 0.26 Eurocent/kWh and from hydro 0.18 Eurocent/kWh.[31] For nuclear the Federal Environment Agency indicates no value, as different studies have results that vary by a factor of 1,000. It recommends the nuclear given the huge uncertainty, with the cost of the next inferior energy source to evaluate.[32] Based on this recommendation the Federal Environment Agency, and with their own method, the Forum Ecological-social market economy, arrive at external environmental costs of nuclear energy at 10.7 to 34 ct/kWh.[33]
Additional cost factors
Calculations often do not include wider system costs associated with each type of plant, such as long distance transmission connections to grids, or balancing and reserve costs. Calculations do not include externalities such as health damage by coal plants, nor the effect of CO2 emissions on the climate change, ocean acidification and eutrophication, ocean current shifts. Decommissioning costs of nuclear plants are usually not included (The USA is an exception, because the cost of decommissioning is included in the price of electricity, per the Nuclear Waste Policy Act), is therefore not full cost accounting. These types of items can be explicitly added as necessary depending on the purpose of the calculation. It has little relation to actual price of power, but assists policy makers and others to guide discussions and decision making.
These are not minor factors but very significantly affect all responsible power decisions:
Comparisons of life-cycle greenhouse gas emissions show coal, for instance, to be radically higher in terms of GHGs than any alternative. Accordingly, in the analysis below, carbon captured coal is generally treated as a separate source rather than being averaged in with other coal.
Other environmental concerns with electricity generation include acid rain, ocean acidification and effect of coal extraction on watersheds.
Various human health concerns with electricity generation, including asthma and smog, now dominate decisions in developed nations that incur health care costs publicly. A Harvard University Medical School study estimates the US health costs of coal alone at between 300 and 500 billion US dollars annually.[34]
While cost per kWh of transmission varies drastically with distance, the long complex projects required to clear or even upgrade transmission routes make even attractive new supplies often uncompetitive with conservation measures (see below), because the timing of payoff must take the transmission upgrade into account.
Current global studies

Lazard (2018)
In November, 2018, Lazard found that not only are utility-scale solar and wind cheaper than fossil fuels, "[i]n some scenarios, alternative energy costs have decreased to the point that they are now at or below the marginal cost of conventional generation."
Overall, Lazard found "The low end levelized cost of onshore wind-generated energy is $29/MWh, compared to an average illustrative marginal cost of $36/MWh for coal. The levelized cost of utility-scale solar is nearly identical to the illustrative marginal cost of coal, at $36/MWh. This comparison is accentuated when subsidizing onshore wind and solar, which results in levelized costs of energy of $14/MWh and $32/MWh, respectively. ... The mean levelized cost of energy of utility-scale PV technologies is down approximately 13% from last year and the mean levelized cost of energy of onshore wind has declined almost 7%."[35]
Bloomberg (2018)
Bloomberg New Energy Finance estimates a "global LCOE for onshore wind [of] $55 per megawatt-hour, down 18% from the first six months of [2017], while the equivalent for solar PV without tracking systems is $70 per MWh, also down 18%." Bloomberg does not provide its global public LCOEs for fossil fuels, but it notes in India they are significantly more expensive: "BNEF is now showing benchmark LCOEs for onshore wind of just $39 per MWh, down 46% on a year ago, and for solar PV at $41, down 45%. By comparison, coal comes in at $68 per MWh, and combined-cycle gas at $93." [36][37]
IRENA (2018)
The International Renewable Energy Agency (IRENA) released a study based on comprehensive international datasets in January 2018 which projects the fall by 2020 of the kilowatt cost of electricity from utility scale renewable projects such as onshore wind farms to a point equal or below that of electricity from conventional sources.[38]
Banks (2018)
The European Bank for Reconstruction and Development (EBRD) says that "renewables are now cheapest energy source", elaborating: "the Bank believes that renewable energy markets in many of the countries where it invests have reached a stage where the introduction of competitive auctions will lead both to a steep drop in electricity prices and an increase in investment." [39] The World Bank (World Bank) President Jim Yong Kim agreed on 10 October 2018: "We are required by our by-laws to go with the lowest cost option, and renewables have now come below the cost of [fossil fuels]." [40]
Regional and historical studies
Australia

According to various studies, the cost for wind and solar has dramatically reduced since 2006. For example, the Australian Climate Council states that over the 5 years between 2009–2014 solar costs fell by 75% making them comparable to coal, and are expected to continue dropping over the next 5 years by another 45% from 2014 prices.[42] They also found that wind has been cheaper than coal since 2013, and that coal and gas will become less viable as subsidies are withdrawn and there is the expectation that they will eventually have to pay the costs of pollution.[42]
A CO2CRC report, printed on the 27th of November 2015, titled , provides the following updated situation in Australia. "The updated LCOE analysis finds that in 2015 natural gas combined cycle and supercritical pulverised coal (both black and brown) plants have the lowest LCOEs of the technologies covered in the study. Wind is the lowest cost large-scale renewable energy source, while rooftop solar panels are competitive with retail electricity prices. By 2030 the LCOE ranges of both conventional coal and gas technologies as well as wind and large-scale solar converge to a common range of A$50 to A$100 per megawatt hour."
An updated report, posted on the 27th of September 2017, titled "", indicated that a 100% renewables system is competitive with new-build supercritical (ultrasupercritical) coal, which, according to the Jacobs calculations in the report link above, would come in at around A$75(80) per MWh between 2020 and 2050. This projection for supercritical coal is consistent with other studies by the  (A$80 per MWh) and used by  (A$65-80 per MWh).
France

The International Energy Agency and EDF have estimated for 2011 the following costs. For nuclear power, they include the costs due to new safety investments to upgrade the French nuclear plant after the Fukushima Daiichi nuclear disaster; the cost for those investments is estimated at 4 €/MWh. Concerning solar power, the estimate of 293 €/MWh is for a large plant capable of producing in the range of 50–100 GWh/year located in a favorable location (such as in Southern Europe). For a small household plant that can produce around 3 MWh/year, the cost is between 400 and 700 €/MWh, depending on location. Solar power was by far the most expensive renewable source of electricity among the technologies studied, although increasing efficiency and longer lifespan of photovoltaic panels together with reduced production costs have made this source of energy more competitive since 2011. By 2017, the cost of photovoltaic solar power had decreased to less than 50 €/MWh.

Germany

In November 2013, the Fraunhofer Institute for Solar Energy Systems ISE assessed the levelised generation costs for newly built power plants in the German electricity sector.[45] PV systems reached LCOE between 0.078 and 0.142 Euro/kWh in the third quarter of 2013, depending on the type of power plant (ground-mounted utility-scale or small rooftop solar PV) and average German insolation of 1000 to 1200 kWh/m² per year (GHI). There are no LCOE-figures available for electricity generated by recently built German nuclear power plants as none have been constructed since the late 1980s. An update of the ISE study was published in March 2018[44].

Japan

A 2010 study by the Japanese government (pre-Fukushima disaster), called the Energy White Paper, concluded the cost for kilowatt hour was ¥49 for solar, ¥10 to ¥14 for wind, and ¥5 or ¥6 for nuclear power. Masayoshi Son, an advocate for renewable energy, however, has pointed out that the government estimates for nuclear power did not include the costs for reprocessing the fuel or disaster insurance liability. Son estimated that if these costs were included, the cost of nuclear power was about the same as wind power.[46][47][48]
United Kingdom
The Institution of Engineers and Shipbuilders in Scotland commissioned a former Director of Operations of the British National Grid, Colin Gibson, to produce a report on generation levelised costs that for the first time would include some of the transmission costs as well as the generation costs. This was published in December 2011.[49] The institution seeks to encourage debate of the issue, and has taken the unusual step among compilers of such studies of publishing a spreadsheet.[50]
On 27 February 2015 Vattenfall Vindkraft AS agreed to build the Horns Rev 3 offshore wind farm at a price of . This has been quoted as below  per MWh.
In 2013 in the United Kingdom for a new-to-build nuclear power plant (Hinkley Point C: completion 2023), a feed-in tariff of £92.50/MWh (around 142 USD/MWh) plus compensation for inflation with a running time of 35 years was agreed.[51][52]
The Department for Business, Energy and Industrial Strategy (BEIS) publishes regular estimates of the costs of different electricity generation sources, following on the estimates of the merged Department of Energy and Climate Change (DECC). Levelised cost estimates for new generation projects begun in 2015 are listed in the table below.[53]

United States
Energy Information Administration

The following data are from the Energy Information Administration's (EIA) Annual Energy Outlook released in 2015 (AEO2015). They are in dollars per megawatt-hour (2013 USD/MWh). These figures are estimates for plants going into service in 2020.[10] The LCOE below is calculated based off a 30-year recovery period using a real after tax weighted average cost of capital (WACC) of 6.1%. For carbon intensive technologies 3 percentage points are added to the WACC. (This is approximately equivalent fee of $15 per metric ton of carbon dioxide CO
2)
Since 2010, the US Energy Information Administration (EIA) has published the Annual Energy Outlook (AEO), with yearly LCOE-projections for future utility-scale facilities to be commissioned in about five years' time. In 2015, EIA has been criticized by the Advanced Energy Economy (AEE) Institute after its release of the AEO 2015-report to "consistently underestimate the growth rate of renewable energy, leading to 'misperceptions' about the performance of these resources in the marketplace". AEE points out that the average power purchase agreement (PPA) for wind power was already at $24/MWh in 2013. Likewise, PPA for utility-scale solar PV are seen at current levels of $50–$75/MWh.[57] These figures contrast strongly with EIA's estimated LCOE of $125/MWh (or $114/MWh including subsidies) for solar PV in 2020.[58]

The electricity sources which had the most decrease in estimated costs over the period 2010 to 2017 were solar photovoltaic (down 81%), onshore wind (down 63%) and advanced natural gas combined cycle (down 32%).
For utility-scale generation put into service in 2040, the EIA estimated in 2015 that there would be further reductions in the constant-dollar cost of concentrated solar power (CSP) (down 18%), solar photovoltaic (down 15%), offshore wind (down 11%), and advanced nuclear (down 7%). The cost of onshore wind was expected to rise slightly (up 2%) by 2040, while natural gas combined cycle electricity was expected to increase 9% to 10% over the period.[58]

NREL OpenEI (2015)
OpenEI, sponsored jointly by the US DOE and the National Renewable Energy Laboratory (NREL), has compiled a historical cost-of-generation database[67] covering a wide variety of generation sources. Because the data is open source it may be subject to frequent revision.

Note:

Only Median value = only one data point.

Only Max + Min value = Only two data points
California Energy Commission (2014)
LCOE data from the California Energy Commission report titled "Estimated Cost of New Renewable and Fossil Generation in California".[68] The model data was calculated for all three classes of developers: merchant, investor-owned utility (IOU), and publicly owned utility (POU).

Lazard (2015)
In November 2015, the investment bank Lazard headquartered in New York, published its ninth annual study on the current electricity production costs of photovoltaics in the US compared to conventional power generators. The best large-scale photovoltaic power plants can produce electricity at 50 USD per MWh. The upper limit at 60 USD per MWh. In comparison, coal-fired plants are between 65 USD and $150 per MWh, nuclear power at 97 USD per MWh. Small photovoltaic power plants on roofs of houses are still at 184–300 USD per MWh, but which can do without electricity transport costs. Onshore wind turbines are 32–77 USD per MWh. One drawback is the intermittency of solar and wind power. The study suggests a solution in batteries as a storage, but these are still expensive so far.[69][70]
Lazard's long standing Levelized Cost of Energy (LCOE) report is widely considered and industry benchmark.  In 2015 Lazard published its inaugural Levelized Cost of Storage (LCOS) report, which was developed by the investment bank Lazard in collaboration with the energy consulting firm, Enovation.[71]
Below is the complete list of LCOEs by source from the investment bank Lazard.[69]

NOTE: ** Battery Storage is no longer include in this report (2015). It has been rolled into its own separate report LCOS 1.0, developed in consultation with Enovation Partners (See charts below).
Below are the LCOSs for different battery technologies. This category has traditionally been filled by Diesel Engines. These are "Behind the meter" applications.[72]

Below are the LCOSs for different battery technologies. This category has traditionally been filled by Natural Gas Engines. These are "In front of the meter" applications.[72]

Lazard (2016)
On December 15, 2016 Lazard released version 10[73] of their LCOE report and version 2[74] of their LCOS report.

Lazard (2017)
On November 2, 2017 the investment bank Lazard released version 11[75] of their LCOE report and version 3[76] of their LCOS report.[77]

Below are the unsubsidized LCOSs for different battery technologies for "Behind the Meter" (BTM) applications.[76]

Below are the Unsubsidized LCOSs for different battery technologies "Front of the Meter" (FTM) applications.[76]

Note: Flow battery value range estimates
Global
IEA and NEA (2015)
The International Energy Agency and the Nuclear Energy Agency published a joint study in 2015 on LCOE data internationally.[78][79]
Other studies and analysis
Buffett Contract (2015)
In a power purchase agreement in the United States in July 2015 for a period of 20 years of solar power will be paid 3.87 UScent per kilowatt hour (38.7 USD/MWh). The solar system, which produces this solar power, is in Nevada (USA) and has 100 MW capacity.[80]
Sheikh Mohammed Bin Rashid solar farm (2016)
In the spring of 2016 a winning bid of 2.99 US cents per kilowatt-hour of photovoltaic solar energy was achieved for the next (800MW capacity) phase of the Sheikh Mohammed Bin Rashid solar farm in Dubai.[81]
Brookings Institution (2014)
In 2014, the Brookings Institution published The Net Benefits of Low and No-Carbon Electricity Technologies which states, after performing an energy and emissions cost analysis, that "The net benefits of new nuclear, hydro, and natural gas combined cycle plants far outweigh the net benefits of new wind or solar plants", with the most cost effective low carbon power technology being determined to be nuclear power.[82][83]
Brazilian electricity mix: the Renewable and Non-renewable Exergetic Cost (2014)

As long as exergy stands for the useful energy required for an economic activity to be accomplished, it is reasonable to evaluate the cost of the energy on the basis of its exergy content. Besides, as exergy can be considered as measure of the departure of the environmental conditions, it also serves as an indicator of environmental impact, taking into account both the efficiency of supply chain (from primary exergy inputs) and the efficiency of the production processes. In this way, exergoeconomy can be used to rationally distribute the exergy costs and CO
2 emission cost among the products and by-products of a highly integrated Brazilian electricity mix. Based on the thermoeconomy methodologies, some authors[84] have shown that exergoeconomy provides an opportunity to quantify the renewable and non-renewable specific exergy consumption; to properly allocate the associated CO
2 emissions among the streams of a given production route; as well as to determine the overall exergy conversion efficiency of the production processes. Accordingly, the non-renewable unit exergy cost (cNR) [kJ/kJ] is defined as the rate of non-renewable exergy necessary to produce one unit of exergy rate/flow rate of a substance, fuel, electricity, work or heat flow, whereas the Total Unit Exergy Cost (cT) includes the Renewable (cR) and Non-Renewable Unit Exergy Costs. Analogously, the CO
2 emission cost (cCO
2) [gCO
2/kJ] is defined as the rate of CO
2 emitted to obtain one unit of exergy rate/flow rate.[84]
Renewables
Photovoltaics

Photovoltaic prices have fallen from $76.67 per watt in 1977 to nearly $0.23 per watt in August 2017, for crystalline silicon solar cells.[86][87] This is seen as evidence supporting Swanson's law, which states that solar cell prices fall 20% for every doubling of cumulative shipments. The famous Moore's law calls for a doubling of transistor count every two years.
By 2011, the price of PV modules per MW had fallen by 60% since 2008, according to Bloomberg New Energy Finance estimates, putting solar power for the first time on a competitive footing with the retail price of electricity in some sunny countries; an alternative and consistent price decline figure of 75% from 2007 to 2012 has also been published,[88] though it is unclear whether these figures are specific to the United States or generally global. The levelised cost of electricity (LCOE) from PV is competitive with conventional electricity sources in an expanding list of geographic regions,[6] particularly when the time of generation is included, as electricity is worth more during the day than at night.[89] There has been fierce competition in the supply chain, and further improvements in the levelised cost of energy for solar lie ahead, posing a growing threat to the dominance of fossil fuel generation sources in the next few years.[90] As time progresses, renewable energy technologies generally get cheaper,[91][92] while fossil fuels generally get more expensive:
The less solar power costs, the more favorably it compares to conventional power, and the more attractive it becomes to utilities and energy users around the globe. Utility-scale solar power [could in 2011] be delivered in California at prices well below $100/MWh ($0.10/kWh) less than most other peak generators, even those running on low-cost natural gas. Lower solar module costs also stimulate demand from consumer markets where the cost of solar compares very favourably to retail electric rates.[93]

In the year 2015, First Solar agreed to supply solar power at 3.87 cents/kWh levelised price from its 100 MW Playa Solar 2 project which is far cheaper than the electricity sale price from conventional electricity generation plants.[94]  From January 2015 through May 2016, records have continued to fall quickly, and solar electricity prices, which have reached levels below 3 cents/kWh, continue to fall.[95]  In August 2016, Chile announced a new record low contract price to provide solar power for $29.10 per megawatt-hour (MWh).[96] In September 2016, Abu Dhabi announced a new record breaking bid price, promising to provide solar power for $24.2 per MWh[97] In October 2017, Saudi Arabia announced a further low contract price to provide solar power for $17.90 per MWh.[98]
With a carbon price of $50/ton (which would raise the price of coal-fired power by 5c/kWh), solar PV is cost-competitive in most locations. The declining price of PV has been reflected in rapidly growing installations, totaling a worldwide cumulative capacity of 297 GW by end 2016. According to some estimates total investment in renewables for 2011 exceeded investment in carbon-based electricity generation.[99]
In the case of self consumption, payback time is calculated based on how much electricity is not brought from the grid. Additionally, using PV solar power to charge DC batteries, as used in Plug-in Hybrid Electric Vehicles and Electric Vehicles, leads to greater efficiencies, but higher costs. Traditionally, DC generated electricity from solar PV must be converted to AC for buildings, at an average 10% loss during the conversion. Inverter technology is rapidly improving and current equipment has reached 99% efficiency for small scale residential,[100] while commercial scale three-phase equipment can reach well above 98% efficiency. However, an additional efficiency loss occurs in the transition back to DC for battery driven devices and vehicles, and using various interest rates and energy price changes were calculated to find present values that range from $2,057.13 to $8,213.64 (analysis from 2009).[101]
It is also possible to combine solar PV with other technologies to make hybrid systems, which enable more stand alone systems. The calculation of LCOEs becomes more complex, but can be done by aggregating the costs and the energy produced by each component. As for example, PV and cogen and batteries [102] while reducing energy- and electricity-related greenhouse gas emissions as compared to conventional sources.[103]
Solar thermal
LCOE of solar thermal power with energy storage which can operate round the clock on demand, has fallen to AU$78/MWh (US$61/MWh) in August 2017.[104] Though solar thermal plants with energy storage can work as stand alone systems, combination with solar PV power can deliver further cheaper power.[105] Cheaper and dispatchable solar thermal storage power need not depend on costly or polluting coal/gas/oil/nuclear based power generation for ensuring stable grid operation.[106][107]
When a solar thermal storage plant is forced to idle due to lack of sunlight locally during cloudy days, it is possible to consume the cheap excess infirm power from solar PV, wind and hydro power plants (similar to a lesser efficient, huge capacity and low cost battery storage system) by heating the hot molten salt to higher temperature for converting the stored thermal energy in to electricity during the peak demand hours when the electricity sale price is profitable.[108][109]
Wind power

Current land-based wind
In the windy great plains expanse of the central United States new-construction wind power costs in 2017 are compellingly below costs of continued use of existing coal burning plants.  Wind power can be contracted via a power purchase agreement at two cents per kilowatt hour while the operating costs for power generation in existing coal-burning plants remain above three cents.[111]
Current offshore wind
In 2016 the Norwegian Wind Energy Association (NORWEA) estimated the LCoE of a typical Norwegian wind farm at 44€/MWh, assuming a weighted average cost of capital of 8% and an annual 3,500 full load hours, i.e. a capacity factor of 40%. NORWEA went on to estimate the LCoE of the 1GW Fosen Vind onshore wind farm which is expected to be operational by 2020 to be as low as 35€/MWh to 40€/MWh.[112] In November 2016, Vattenfall won a tender to develop the Kriegers Flak windpark in the Baltic Sea for 49.9 €/MWh,[113] and similar levels were agreed for the Borssele offshore wind farms. As of 2016, this is the lowest projected price for electricity produced using offshore wind.
Historic levels
In 2004, wind energy cost a fifth of what it did in the 1980s, and some expected that downward trend to continue as larger multi-megawatt turbines were mass-produced.[114] As of 2012 capital costs for wind turbines are substantially lower than 2008–2010 but are still above 2002 levels.[115] A 2011 report from the American Wind Energy Association stated, "Wind's costs have dropped over the past two years, in the range of 5 to 6 cents per kilowatt-hour recently.... about 2 cents cheaper than coal-fired electricity, and more projects were financed through debt arrangements than tax equity structures last year.... winning more mainstream acceptance from Wall Street's banks.... Equipment makers can also deliver products in the same year that they are ordered instead of waiting up to three years as was the case in previous cycles.... 5,600 MW of new installed capacity is under construction in the United States, more than double the number at this point in 2010. 35% of all new power generation built in the United States since 2005 has come from wind, more than new gas and coal plants combined, as power providers are increasingly enticed to wind as a convenient hedge against unpredictable commodity price moves."[116]
This cost has additionally reduced as wind turbine technology has improved. There are now longer and lighter wind turbine blades, improvements in turbine performance and increased power generation efficiency. Also, wind project capital and maintenance costs have continued to decline.[117] For example, the wind industry in the USA in 2014 was able to produce more power at lower cost by using taller wind turbines with longer blades, capturing the faster winds at higher elevations. This opened up new opportunities in Indiana, Michigan, and Ohio. The price of power from wind turbines built 300 to 400ft (91 to 122m) above the ground can now compete with conventional fossil fuels like coal. Prices have fallen to about 4 cents per kilowatt-hour in some cases and utilities have been increasing the amount of wind energy in their portfolio, saying it is their cheapest option.[118]
See also

Electricity pricing
Comparisons of life-cycle greenhouse gas emissions
Distributed generation
Economics of new nuclear power plants
Demand response
Intermittent energy source
National Grid Reserve Service
Nuclear power in France
List of thermal power station failures
Calculating the cost of the UK Transmission network: Estimating cost per kWh of transmission
List of countries by electricity production from renewable sources
List of U.S. states by electricity production from renewable sources
Environmental concerns with electricity generation
Grid parity

Further reading
. United States Environmental Protection Agency.
. .
 (Nov. 2017)

How much does a solar panel typically cost?