[edit] Characteristics
Heavy metal is traditionally characterized by loud distorted guitars, emphatic rhythms, dense bass-and-drum sound, and vigorous vocals. Metal subgenres variously emphasize, alter, or omit one or more of these attributes. New York Times critic Jon Pareles writes, "In the taxonomy of popular music, heavy metal is a major subspecies of hard-rock—the breed with less syncopation, less blues, more showmanship and more brute force." The typical band lineup includes a drummer, a bassist, a rhythm guitarist, a lead guitarist, and a singer, who may or may not be an instrumentalist. Keyboard instruments are sometimes used to enhance the fullness of the sound.
The electric guitar and the sonic power that it projects through amplification has historically been the key element in heavy metal. The lead role of the guitar in heavy metal often collides with the traditional "frontman" or bandleader role of the vocalist, creating a musical tension as the two "contend for dominance" in a spirit of "affectionate rivalry". Heavy metal "demands the subordination of the voice" to the overall sound of the band. Reflecting metal's roots in the 1960s counterculture, an "explicit display of emotion" is required from the vocals as a sign of authenticity. Critic Simon Frith claims that the metal singer's "tone of voice" is more important than the lyrics. Metal vocals vary widely in style, from the multioctave, theatrical approach of Judas Priest's Rob Halford and Iron Maiden's Bruce Dickinson, to the gruff style of Motörhead's Lemmy and Metallica's James Hetfield, to the growling of many death metal performers.
The prominent role of the bass is also key to the metal sound, and the interplay of bass and guitar is a central element. The bass guitar provides the low-end sound crucial to making the music "heavy". Metal basslines vary widely in complexity, from holding down a low pedal point as a foundation to doubling complex riffs and licks along with the lead and/or rhythm guitars. Some bands feature the bass as a lead instrument, an approach popularized by Metallica's Cliff Burton in the early 1980s.
The essence of metal drumming is creating a loud, constant beat for the band using the "trifecta of speed, power, and precision". Metal drumming "requires an exceptional amount of endurance", and drummers have to develop "considerable speed, coordination, and dexterity...to play the intricate patterns" used in metal. A characteristic metal drumming technique is the cymbal choke, which consists of striking a cymbal and then immediately silencing it by grabbing it with the other hand (or, in some cases, the same striking hand), producing a burst of sound. The metal drum setup is generally much larger than those employed in other forms of rock music.
In live performance, loudness—an "onslaught of sound," in sociologist Deena Weinstein's description—is considered vital. In his book Metalheads, psychologist Jeffrey Arnett refers to heavy metal concerts as "the sensory equivalent of war." Following the lead set by Jimi Hendrix, Cream and The Who, early heavy metal acts such as Blue Cheer set new benchmarks for volume. As Blue Cheer's Dick Peterson put it, "All we knew was we wanted more power." A 1977 review of a Motörhead concert noted how "excessive volume in particular figured into the band’s impact." Weinstein makes the case that in the same way that melody is the main element of pop and rhythm is the main focus of house music, powerful sound, timbre, and volume are the key elements of metal. She argues that the loudness is designed to "sweep the listener into the sound" and to provide a "shot of youthful vitality."
[edit] Musical language
[edit] Rhythm and tempo
The rhythm in metal songs is emphatic, with deliberate stresses. Weinstein observes that the wide array of sonic effects available to metal drummers enables the "rhythmic pattern to take on a complexity within its elemental drive and insistency." In many heavy metal songs, the main groove is characterized by short, two-note or three-note rhythmic figures—generally made up of 8th or 16th notes. These rhythmic figures are usually performed with a staccato attack created by using a palm-muted technique on the rhythm guitar.
Brief, abrupt, and detached rhythmic cells are joined into rhythmic phrases with a distinctive, often jerky texture. These phrases are used to create rhythmic accompaniment and melodic figures called riffs, which help to establish thematic hooks. Heavy metal songs also use longer rhythmic figures such as whole note- or dotted quarter note-length chords in slow-tempo power ballads. The tempos in early heavy metal music tended to be "slow, even ponderous." By the late 1970s, however, metal bands were employing a wide variety of tempos. In the 2000s, metal tempos range from slow ballad tempos (quarter note = 60 beats per minute) to extremely fast blast beat tempos (quarter note = 350 beats per minute).
[edit] Harmony
One of the signatures of the genre is the guitar power chord. In technical terms, the power chord is relatively simple: it involves just one main interval, generally the perfect fifth, though an octave may be added as a doubling of the root. Although the perfect fifth interval is the most common basis for the power chord, power chords are also based on different intervals such as the minor third, major third, perfect fourth, diminished fifth, or minor sixth. Most power chords are also played with a consistent finger arrangement that can be slid easily up and down the fretboard.
[edit] Typical harmonic structures
Heavy metal is usually based on riffs created with three main harmonic traits: modal scale progressions, tritone and chromatic progressions, and the use of pedal points. Traditional heavy metal tends to employ modal scales, in particular the Aeolian and Phrygian modes. Harmonically speaking, this means the genre typically incorporates modal chord progressions such as the Aeolian progressions I-VI-VII, I-VII-(VI), or I-VI-IV-VII and Phrygian progressions implying the relation between I and ♭II (I-♭II-I, I-♭II-III, or I-♭II-VII for example). Tense-sounding chromatic or tritone relationships are used in a number of metal chord progressions. The tritone, an interval spanning three whole tones—such as C and F#—was a forbidden dissonance in medieval ecclesiastical singing, which led monks to call it diabolus in musica—"the devil in music." Because of that original symbolic association, it came to be heard in Western cultural convention as "evil". Heavy metal has made extensive use of the tritone in guitar solos and riffs, such as in the beginning of "Black Sabbath".
Heavy metal songs often make extensive use of pedal point as a harmonic basis. A pedal point is a sustained tone, typically in the bass range, during which at least one foreign (i.e., dissonant) harmony is sounded in the other parts.
[edit] Relationship with classical music
Robert Walser argues that, alongside blues and R&B, the "assemblage of disparate musical styles known...as 'classical music'" has been a major influence on heavy metal since the genre's earliest days. He claims that metal's "most influential musicians have been guitar players who have also studied classical music. Their appropriation and adaptation of classical models sparked the development of a new kind of guitar virtuosity [and] changes in the harmonic and melodic language of heavy metal." The Grove Music Online states that the "1980s brought on ...the widespread adaptation of chord progressions and virtuosic practices from 18th-century European models, especially Bach and Vivaldi, by influential guitarists such as Van Halen, Randy Rhoads and Yngwie Malmsteen".
Although a number of metal musicians cite classical composers as inspiration, classical and metal are rooted in different cultural traditions and practices—classical in the art music tradition, metal in the popular music tradition. As musicologists Nicolas Cook and Nicola Dibben note, "Analyses of popular music also sometimes reveal the influence of 'art traditions.' An example is Walser’s linkage of heavy metal music with the ideologies and even some of the performance practices of nineteenth-century Romanticism. However, it would be clearly wrong to claim that traditions such as blues, rock, heavy metal, rap or dance music derive primarily from 'art music.'"
[edit] Lyrical themes
Black Sabbath and the many metal bands they inspired have concentrated lyrically "on dark and depressing subject matter to an extent hitherto unprecedented in any form of pop music," according to scholars David Hatch and Stephen Millward. They take as an example Sabbath's 1970 album Paranoid, which "included songs dealing with personal trauma—'Paranoid' and 'Fairies Wear Boots' (which described the unsavoury side effects of drug-taking)—as well as those confronting wider issues, such as the self-explanatory 'War Pigs' and 'Hand of Doom.'" Nuclear annihilation was addressed in later metal songs such as Iron Maiden's "2 Minutes to Midnight" and Ozzy Osbourne's "Killer of Giants". Death is a predominant theme in heavy metal, routinely featuring in the lyrics of bands as otherwise widely different as Slayer and W.A.S.P. The more extreme forms of death metal and grindcore tend to have aggressive and gory lyrics.
Deriving from the genre's roots in blues music, sex is another important topic—a thread running from Led Zeppelin's suggestive lyrics to the more explicit references of glam and nu metal bands. Romantic tragedy is a standard theme of gothic and doom metal, as well as of nu metal, where teenage angst is another central topic. Heavy metal songs often feature outlandish, fantasy-inspired lyrics, lending them an escapist quality. Iron Maiden's songs, for instance, were frequently inspired by mythology, fiction, and poetry, such as Iron Maiden's "Rime of the Ancient Mariner," based on the Samuel Taylor Coleridge poem. Led Zeppelin lyrics often reference Lord of the Rings as well as other mythology and folklore, such as in the songs "The Battle of Evermore", "Immigrant Song", "Ramble On", "No Quarter", and "Achilles Last Stand". Other examples include Black Sabbath's "The Wizard," Megadeth's "The Conjuring" and "Five Magics," and Judas Priest's "Dreamer Deceiver". Since the 1980s, with the rise of thrash metal and songs such as Metallica's "...And Justice for All" and Megadeth's "Peace Sells", more metal lyrics have included sociopolitical commentary. Genres such as melodic death metal, progressive metal, and black metal often explore philosophical themes.
The thematic content of heavy metal has long been a target of criticism. According to Jon Pareles, "Heavy metal's main subject matter is simple and virtually universal. With grunts, moans and subliterary lyrics, it celebrates...a party without limits.... [T]he bulk of the music is stylized and formulaic." Music critics have often deemed metal lyrics juvenile and banal, and others have objected to what they see as advocacy of misogyny and the occult. During the 1980s, the Parents Music Resource Center petitioned the U.S. Congress to regulate the popular music industry due to what the group asserted were objectionable lyrics, particularly those in heavy metal songs. In 1990, Judas Priest was sued in American court by the parents of two young men who had shot themselves five years earlier, allegedly after hearing the subliminal statement "do it" in a Priest song. While the case attracted a great deal of media attention, it was ultimately dismissed. In some predominantly Muslim countries, heavy metal has been officially denounced as a threat to traditional values. In countries including Morocco, Egypt, Lebanon, and Malaysia, there have been incidents of heavy metal musicians and fans being arrested and incarcerated.
[edit] Image and fashion
As with much popular music, visual imagery plays a large role in heavy metal. In addition to its sound and lyrics, a heavy metal band's "image" is expressed in album sleeve art, logos, stage sets, clothing, and music videos. Some heavy metal acts such as Alice Cooper, Kiss, and Gwar have become known as much for their outrageous performance personas and stage shows as for their music.
Down-the-back long hair, according to Weinstein, is the "most crucial distinguishing feature of metal fashion." Originally adopted from the hippie subculture, by the 1980s and 1990s heavy metal hair "symbolised the hate, angst and disenchantment of a generation that seemingly never felt at home," according to journalist Nader Rahman. Long hair gave members of the metal community "the power they needed to rebel against nothing in general."
The classic uniform of heavy metal fans consists of "blue jeans, black T-shirts, boots and black leather or jeans jackets.... T-shirts are generally emblazoned with the logos or other visual representations of favorite metal bands." Metal fans also "appropriated elements from the S&M community (chains, metal studs, skulls, leather and crosses)." In the 1980s, a range of sources, from punk and goth music to horror films, influenced metal fashion. Many metal performers of the 1970s and 1980s used radically shaped and brightly colored instruments to enhance their stage appearance. Fashion and personal style was especially important for glam metal bands of the era. Performers typically wore long, dyed, hairspray-teased hair (hence the nickname, "hair metal"); makeup such as lipstick and eyeliner; gaudy clothing, including leopard-skin-printed shirts or vests and tight denim, leather, or spandex pants; and accessories such as headbands and jewelry. Pioneered by the heavy metal act X Japan in the late 1980s, bands in the Japanese movement known as visual kei—which includes many nonmetal groups—emphasize elaborate costumes, hair, and makeup.
[edit] Physical gestures
Many metal musicians when performing live engage in headbanging, which involves rhythmically beating time with the head, often emphasized by long hair. The corna, or devil horns, hand gesture, also widespread, was popularized by vocalist Ronnie James Dio while with Black Sabbath and Dio. Gene Simmons of Kiss claims to have been the first to make the gesture in concert.
Attendees of metal concerts do not dance in the usual sense; Deena Weinstein has argued that this is due to the music's largely male audience and "extreme heterosexualist ideology." She identifies two primary body movements that substitute for dancing: headbanging and an arm thrust that is both a sign of appreciation and a rhythmic gesture. The performance of air guitar is popular among metal fans both at concerts and listening to records at home. Other concert audience activities include stage diving, crowd surfing, pushing and shoving in a chaotic mêlée called moshing, and displaying the corna hand symbol.
[edit] Fan subculture
Deena Weinstein argues that heavy metal has outlasted many other rock genres largely due to the emergence of an intense, exclusionary, strongly masculine subculture. While the metal fanbase is largely young, white, male, and blue-collar, the group is "tolerant of those outside its core demographic base who follow its codes of dress, appearance, and behavior." Identification with the subculture is strengthened not only by the shared experience of concert-going and shared elements of fashion, but also by contributing to metal magazines and, more recently, websites.
The metal scene has been characterized as a "subculture of alienation", with its own code of authenticity. This code puts several demands on performers: they must appear both completely devoted to their music and loyal to the subculture that supports it; they must appear disinterested in mainstream appeal and radio hits; and they must never "sell out". For the fans themselves, the code promotes "opposition to established authority, and separateness from the rest of society." Scholars of metal have noted the tendency of fans to classify and reject some performers (and some other fans) as "posers" "who pretended to be part of the subculture, but who were deemed to lack authenticity and sincerity."
[edit] Etymology
The origin of the term heavy metal in a musical context is uncertain. The phrase has been used for centuries in chemistry and metallurgy. An early use of the term in modern popular culture was by countercultural writer William S. Burroughs. His 1962 novel The Soft Machine includes a character known as "Uranian Willy, the Heavy Metal Kid." Burroughs's next novel, Nova Express (1964), develops the theme, using heavy metal as a metaphor for addictive drugs: "With their diseases and orgasm drugs and their sexless parasite life forms—Heavy Metal People of Uranus wrapped in cool blue mist of vaporized bank notes—And The Insect People of Minraud with metal music."
Metal historian Ian Christe describes what the components of the term mean in "hippiespeak": "heavy" is roughly synonymous with "potent" or "profound," and "metal" designates a certain type of mood, grinding and weighted as with metal. The word "heavy" in this sense was a basic element of beatnik and later countercultural slang, and references to "heavy music"—typically slower, more amplified variations of standard pop fare—were already common by the mid-1960s. Iron Butterfly's debut album, released in early 1968, was titled Heavy. The first recorded use of heavy metal is a reference to a motorcycle in the Steppenwolf song "Born to Be Wild," also released that year: "I like smoke and lightning/Heavy metal thunder/Racin' with the wind/And the feelin' that I'm under." A late, and disputed, claim about the source of the term was made by "Chas" Chandler, former manager of the Jimi Hendrix Experience. In a 1995 interview on the PBS program Rock and Roll, he asserted that heavy metal "was a term originated in a New York Times article reviewing a Jimi Hendrix performance," in which the author likened the event to "listening to heavy metal falling from the sky." A source for Chandler's claim has never been found.
The first documented use of the phrase to describe a type of rock music identified to date appears in a review by Barry Gifford. In the May 11, 1968, issue of Rolling Stone, he wrote about the album A Long Time Comin' by U.S. band Electric Flag: "Nobody who's been listening to Mike Bloomfield—either talking or playing—in the last few years could have expected this. This is the new soul music, the synthesis of white blues and heavy metal rock." Other early documented uses of the phrase are from reviews by critic Mike Saunders. In the November 12, 1970, issue of Rolling Stone, he commented on an album put out the previous year by the British band Humble Pie: "Safe As Yesterday Is, their first American release, proved that Humble Pie could be boring in lots of different ways. Here they were a noisy, unmelodic, heavy metal-leaden shit-rock band with the loud and noisy parts beyond doubt. There were a couple of nice songs...and one monumental pile of refuse." He described the band's latest, self-titled release as "more of the same 27th-rate heavy metal crap." In a review of Sir Lord Baltimore's Kingdom Come in the May 1971 Creem, Saunders wrote, "Sir Lord Baltimore seems to have down pat most all the best heavy metal tricks in the book." Creem critic Lester Bangs is credited with popularizing the term via his early 1970s essays on bands such as Led Zeppelin and Black Sabbath. Through the decade, heavy metal was used by certain critics as a virtually automatic putdown. In 1979, lead New York Times popular music critic John Rockwell described what he called "heavy-metal rock" as "brutally aggressive music played mostly for minds clouded by drugs," and, in a different article, as "a crude exaggeration of rock basics that appeals to white teenagers."
Coined by Black Sabbath drummer, Bill Ward, "downer rock" was one of the earliest terms used to describe this style of music and was applied to such acts as Sabbath and Bloodrock. Classic Rock magazine described the downer rock culture revolving around the use of Quaaludes and the drinking of wine. Later the term would be replaced by "heavy metal."
The terms "heavy metal" and "hard rock" have often been used interchangeably, particularly in discussing bands of the 1970s, a period when the terms were largely synonymous. For example, the 1983 Rolling Stone Encyclopedia of Rock & Roll includes this passage: "known for its aggressive blues-based hard-rock style, Aerosmith was the top American heavy-metal band of the mid-Seventies."
[edit] History
[edit] Antecedents: mid-1960s
While heavy metal's quintessential guitar style, built around distortion-heavy riffs and power chords, traces its roots to the late 1950s instrumentals of American Link Wray, the genre's direct lineage begins in the mid-1960s. American blues music was a major influence on the early British rockers of the era. Bands like The Rolling Stones and The Yardbirds developed blues-rock by recording covers of many classic blues songs, often speeding up the tempos. As they experimented with the music, the UK blues-based bands—and the U.S. acts they influenced in turn—developed what would become the hallmarks of heavy metal, in particular, the loud, distorted guitar sound. The Kinks played a major role in popularizing this sound with their 1964 hit "You Really Got Me." A significant contributor to the emerging guitar sound was the feedback facilitated by the new generation of amplifiers.
In addition to The Kinks' Dave Davies, other guitarists such as The Who's Pete Townshend and the Tridents' Jeff Beck were experimenting with feedback. Where the blues-rock drumming style started out largely as simple shuffle beats on small kits, drummers began using a more muscular, complex, and amplified approach to match and be heard against the increasingly loud guitar. Vocalists similarly modified their technique and increased their reliance on amplification, often becoming more stylized and dramatic. In terms of sheer volume, especially in live performance, The Who's "bigger-louder-wall-of-Marshalls" approach was seminal. Simultaneous advances in amplification and recording technology made it possible to successfully capture the power of this heavier approach on record.
The combination of blues-rock with psychedelic rock formed much of the original basis for heavy metal. One of the most influential bands in forging the merger of genres was the British power trio Cream, who derived a massive, heavy sound from unison riffing between guitarist Eric Clapton and bassist Jack Bruce, as well as Ginger Baker's double bass drumming. Their first two LPs, Fresh Cream (1966) and Disraeli Gears (1967), are regarded as essential prototypes for the future style. The Jimi Hendrix Experience's debut album, Are You Experienced (1967), was also highly influential. Hendrix's virtuosic technique would be emulated by many metal guitarists and the album's most successful single, "Purple Haze," is identified by some as the first heavy metal hit. Vanilla Fudge, whose first album also came out in 1967, have been called "one of the few American links between psychedelia and what soon became heavy metal."
[edit] Origins: late 1960s and early 1970s
In 1968, the sound that would become known as heavy metal began to coalesce. That January, the San Francisco band Blue Cheer released a cover of Eddie Cochran's classic "Summertime Blues," from their debut album Vincebus Eruptum, that many consider the first true heavy metal recording. The same month, Steppenwolf released its self-titled debut album, including "Born to Be Wild," which refers to "heavy metal" in the lyrics. In July, another two epochal records came out: The Yardbirds' "Think About It"—B-side of the band's last single—with a performance by guitarist Jimmy Page anticipating the metal sound he would soon make famous; and Iron Butterfly's In-A-Gadda-Da-Vida, with its 17-minute-long title track, a prime candidate for first-ever heavy metal album. In August, The Beatles' single version of "Revolution," with its redlined guitar and drum sound, set new standards for distortion in a top-selling context.
The Jeff Beck Group, whose leader had preceded Page as The Yardbirds' guitarist, released its debut record that same month: Truth featured some of the "most molten, barbed, downright funny noises of all time," breaking ground for generations of metal ax-slingers. In October, Page's new band, Led Zeppelin, made its live debut. The Beatles' so-called White Album, which also came out that month, included "Helter Skelter," then one of the heaviest-sounding songs ever released by a major band. The Pretty Things' rock opera S.F. Sorrow, released in December, featured "proto heavy metal" songs such as "Old Man Going."
In January 1969, Led Zeppelin's self-titled debut album was released and reached number 10 on the Billboard album chart. In July, Zeppelin and a power trio with a Cream-inspired, but cruder sound, Grand Funk Railroad, played the Atlanta Pop Festival. That same month, another Cream-rooted trio led by Leslie West released Mountain, an album filled with heavy blues-rock guitar and roaring vocals. In August, the group—now itself dubbed Mountain—played an hour-long set at the Woodstock Festival. Grand Funk's debut album, On Time, also came out that month. In the fall, Led Zeppelin II went to number 1 and the album's single "Whole Lotta Love" hit number 4 on the Billboard pop chart. The metal revolution was under way.
Led Zeppelin defined central aspects of the emerging genre, with Page's highly distorted guitar style and singer Robert Plant's dramatic, wailing vocals. Other bands, with a more consistently heavy, "purely" metal sound, would prove equally important in codifying the genre. The 1970 releases by Black Sabbath (Black Sabbath and Paranoid) and Deep Purple (In Rock) were crucial in this regard. Black Sabbath had developed a particularly heavy sound in part due to an industrial accident guitarist Tony Iommi suffered before cofounding the band. Unable to play normally, Iommi had to tune his guitar down for easier fretting and rely on power chords with their relatively simple fingering. Deep Purple had fluctuated between styles in its early years, but by 1969 vocalist Ian Gillan and guitarist Ritchie Blackmore had led the band toward the developing heavy metal style. In 1970, Black Sabbath and Deep Purple scored major UK chart hits with "Paranoid" and "Black Night," respectively. That same year, two other British bands released debut albums in a heavy metal mode: Uriah Heep with Very 'eavy... Very 'umble and UFO with UFO 1. Budgie brought the new metal sound into a power trio context. The occult lyrics and imagery employed by Black Sabbath and Uriah Heep would prove particularly influential; Led Zeppelin also began foregrounding such elements with its fourth album, released in 1971.
On the other side of the Atlantic, the trend-setting group was Grand Funk Railroad, "the most commercially successful American heavy-metal band from 1970 until they disbanded in 1976, [they] established the Seventies success formula: continuous touring." Other bands identified with metal emerged in the U.S., such as Dust (first LP in 1971), Blue Öyster Cult (1972), and Kiss (1974). In Germany, the Scorpions debuted with Lonesome Crow in 1972. Blackmore, who had emerged as a virtuoso soloist with Deep Purple's Machine Head (1972), quit the group in 1975 to form Rainbow. These bands also built audiences via constant touring and increasingly elaborate stage shows. As described above, there are arguments about whether these and other early bands truly qualify as "heavy metal" or simply as "hard rock." Those closer to the music's blues roots or placing greater emphasis on melody are now commonly ascribed the latter label. AC/DC, which debuted with High Voltage in 1976, is a prime example. The 1983 Rolling Stone encyclopedia entry begins, "Australian heavy-metal band AC/DC..." Rock historian Clinton Walker writes, "Calling AC/DC a heavy metal band in the seventies was as inaccurate as it is today.... [They] were a rock 'n' roll band that just happened to be heavy enough for metal." The issue is not only one of shifting definitions, but also a persistent distinction between musical style and audience identification: Ian Christe describes how the band "became the stepping-stone that led huge numbers of hard rock fans into heavy metal perdition."
In certain cases, there is little debate. After Black Sabbath, the next major example is Britain's Judas Priest, which debuted with Rocka Rolla in 1974. In Christe's description, Black Sabbath's
Though Judas Priest did not have a top 40 album in the U.S. until 1980, for many it was the definitive post-Sabbath heavy metal band; its twin-guitar attack, featuring rapid tempos and a nonbluesy, more cleanly metallic sound, was a major influence on later acts. While heavy metal was growing in popularity, most critics were not enamored of the music. Objections were raised to metal's adoption of visual spectacle and other trappings of commercial artifice, but the main offense was its perceived musical and lyrical vacuity: reviewing a Black Sabbath album in the early 1970s, leading critic Robert Christgau described it as "dull and decadent...dim-witted, amoral exploitation."
[edit] Mainstream: late 1970s and 1980s
Punk rock emerged in the mid-1970s as a reaction against contemporary social conditions as well as what was perceived as the overindulgent, overproduced rock music of the time, including heavy metal. Sales of heavy metal records declined sharply in the late 1970s in the face of punk, disco, and more mainstream rock. With the major labels fixated on punk, many newer British heavy metal bands were inspired by the movement's aggressive, high-energy sound and "lo-fi", do it yourself ethos. Underground metal bands began putting out cheaply recorded releases independently to small, devoted audiences. Motörhead, founded in 1975, was the first important band to straddle the punk/metal divide. With the explosion of punk in 1977, others followed. British music papers such as the NME and Sounds took notice, with Sounds writer Geoff Barton christening the movement the "New Wave of British Heavy Metal." NWOBHM bands including Iron Maiden, Saxon, and Def Leppard reenergized the heavy metal genre. Following the lead set by Judas Priest and Motörhead, they toughened up the sound, reduced its blues elements, and emphasized increasingly fast tempos. In 1980, NWOBHM broke into the mainstream, as albums by Iron Maiden and Saxon, as well as Motörhead, reached the British top 10. Though less commercially successful, other NWOBHM bands such as Venom and Diamond Head would have a significant influence on metal's development. In 1981, Motörhead became the first of this new breed of metal bands to top the UK charts with No Sleep 'til Hammersmith.
The first generation of metal bands was ceding the limelight. Deep Purple had broken up soon after Blackmore's departure in 1975, and Led Zeppelin broke up following drummer John Bonham's death in 1980. Black Sabbath was routinely upstaged in concert by its opening act, the Los Angeles band Van Halen. Eddie Van Halen established himself as one of the leading metal guitar virtuosos of the era—his solo on "Eruption," from the band's self-titled 1978 album, is considered a milestone. Randy Rhoads and Yngwie Malmsteen also became famed virtuosos, associated with what would be known as the neoclassical metal style. The adoption of classical elements had been spearheaded by Blackmore and the Scorpions' Uli Jon Roth; this next generation progressed to occasionally using classical nylon-stringed guitars, as Rhoads does on "Dee" from former Sabbath lead singer Ozzy Osbourne's first solo album, Blizzard of Ozz (1980).
Inspired by Van Halen's success, a metal scene began to develop in Southern California during the late 1970s. Based on the clubs of L.A.'s Sunset Strip, bands such as Quiet Riot, Ratt, Mötley Crüe, and W.A.S.P. were influenced by traditional heavy metal of the earlier 1970s and incorporated the theatrics (and sometimes makeup) of glam rock acts such as Alice Cooper and Kiss. The lyrics of these glam metal bands characteristically emphasized hedonism and wild behavior. Musically, the style was distinguished by rapid-fire shred guitar solos, anthemic choruses, and a relatively pop-oriented melodic approach. The glam metal movement—along with similarly styled acts such as New York's Twisted Sister—became a major force in metal and the wider spectrum of rock music.
In the wake of the New Wave of British Heavy Metal and Judas Priest's breakthrough British Steel (1980), heavy metal became increasingly popular in the early 1980s. Many metal artists benefited from the exposure they received on MTV, which began airing in 1981—sales often soared if a band's videos screened on the channel. Def Leppard's videos for Pyromania (1983) made them superstars in America and Quiet Riot became the first domestic heavy metal band to top the Billboard chart with Metal Health (1983). One of the seminal events in metal's growing popularity was the 1983 US Festival in California, where the "heavy metal day" featuring Ozzy Osbourne, Van Halen, Scorpions, Mötley Crüe, Judas Priest, and others drew the largest audiences of the three-day event. Between 1983 and 1984, heavy metal went from an 8 percent to a 20 percent share of all recordings sold in the U.S. Several major professional magazines devoted to the genre were launched, including Kerrang! (in 1981) and Metal Hammer (in 1984), as well as a host of fan journals. In 1985, Billboard declared, "Metal has broadened its audience base. Metal music is no longer the exclusive domain of male teenagers. The metal audience has become older (college-aged), younger (pre-teen), and more female."
By the mid-1980s, glam metal was a dominant presence on the U.S. charts, music television, and the arena concert circuit. New bands such as L.A.'s Warrant and acts from the East Coast like Poison and Cinderella became major draws, while Mötley Crüe and Ratt remained very popular. Bridging the stylistic gap between hard rock and glam metal, New Jersey's Bon Jovi became enormously successful with its third album, Slippery When Wet (1986). The similarly styled Swedish band Europe became international stars with the The Final Countdown (1986). Its title track hit number 1 in 25 countries. In 1987, MTV launched a show, Headbanger's Ball, devoted exclusively to heavy metal videos. However, the metal audience had begun to factionalize, with those in many underground metal scenes favoring more extreme sounds and disparaging the popular style as "lite metal" or "hair metal."
One band that reached diverse audiences was Guns N' Roses. In contrast to their glam metal contemporaries in L.A., they were seen as much rawer and more dangerous. With the release of their chart-topping Appetite for Destruction (1987), they "recharged and almost single-handedly sustained the Sunset Strip sleaze system for several years." The following year, Jane's Addiction emerged from the same L.A. hard-rock club scene with its major label debut, Nothing's Shocking. Reviewing the album, Rolling Stone declared, "as much as any band in existence, Jane's Addiction is the true heir to Led Zeppelin." The group was one of the first to be identified with the "alternative metal" trend that would come to the fore in the next decade. Meanwhile, new bands such as New York's Winger and New Jersey's Skid Row sustained the popularity of the glam metal style.
[edit] Underground metal: 1980s, 1990s, and 2000s
Many subgenres of heavy metal developed outside of the commercial mainstream during the 1980s. Several attempts have been made to map the complex world of underground metal, most notably by the editors of Allmusic, as well as critic Garry Sharpe-Young. Sharpe-Young's multivolume metal encyclopedia separates the underground into five major categories: thrash metal, death metal, black metal, power metal, and the related subgenres of doom and gothic metal.
[edit] Thrash metal
Thrash metal emerged in the early 1980s under the influence of hardcore punk and the New Wave of British Heavy Metal, particularly songs in the revved-up style known as speed metal. The movement began in the United States, with Bay Area thrash metal being the leading scene. The sound developed by thrash groups was faster and more aggressive than that of the original metal bands and their glam metal successors. Low-register guitar riffs are typically overlaid with shredding leads. Lyrics often express nihilistic views or deal with social issues using visceral, gory language. Thrash has been described as a form of "urban blight music" and "a palefaced cousin of rap."
The subgenre was popularized by the "Big Four of Thrash": Metallica, Anthrax, Megadeth, and Slayer. Three German bands, Kreator, Sodom, and Destruction, played a central role in bringing the style to Europe. Others, including San Francisco Bay Area's Testament and Exodus, New Jersey's Overkill, and Brazil's Sepultura, also had a significant impact. While thrash began as an underground scene, and remained largely that for almost a decade, the leading bands in the movement began to reach a wider audience. Metallica brought the sound into the top 40 of the Billboard album chart in 1986 with Master of Puppets; two years later, the band's ...And Justice for All hit number 6, while Megadeth and Anthrax had top 40 records.
Though less commercially successful than the rest of the Big Four, Slayer released one of the genre's definitive records: Reign in Blood (1986) was described by Kerrang! as the "heaviest album of all time." Two decades later, Metal Hammer named it the best album of the preceding twenty years. Slayer attracted a following among far-right skinheads, and accusations of promoting violence and Nazi themes have dogged the band. In the early 1990s, thrash achieved breakout success, challenging and redefining the metal mainstream. Metallica's self-titled 1991 album topped the Billboard chart , Megadeth's Countdown to Extinction (1992) hit number 2 , Anthrax and Slayer cracked the top 10 , and albums by regional bands such as Testament and Sepultura entered the top 100.
[edit] Death metal
Thrash soon began to evolve and split into more extreme metal genres. "Slayer's music was directly responsible for the rise of death metal," according to MTV News. The NWOBHM band Venom was also an important progenitor. The death metal movement in both North America and Europe adopted and emphasized the elements of blasphemy and diabolism employed by such acts. Florida's Death and the Bay Area's Possessed are recognized as seminal bands in the style. Both groups have been credited with inspiring the subgenre's name, the latter via its 1984 demo Death Metal and the song "Death Metal," from its 1985 debut album Seven Churches (1985).
Death metal utilizes the speed and aggression of both thrash and hardcore, fused with lyrics preoccupied with Z-grade slasher movie violence and Satanism. Death metal vocals are typically bleak, involving guttural "death growls," high-pitched screaming, the "death rasp," and other uncommon techniques. Complementing the deep, aggressive vocal style are downtuned, highly distorted guitars and extremely fast percussion, often with rapid double bass drumming and "wall of sound"–style blast beats. Frequent tempo and time signature changes and syncopation are also typical.
Death metal, like thrash metal, generally rejects the theatrics of earlier metal styles, opting instead for an everyday look of ripped jeans and plain leather jackets. One major exception to this rule was Deicide's Glen Benton, who branded an inverted cross on his forehead and wore armor on stage. Morbid Angel adopted neo-fascist imagery. These two bands, along with Death and Obituary, were leaders of the major death metal scene that emerged in Florida in the mid-1980s. In the UK, the related style of grindcore, led by bands such as Napalm Death and Extreme Noise Terror, emerged out of the anarcho-punk movement. A large Scandinavian death metal scene, with bands such as Sweden's Entombed and Dismember, began to develop as well. Out of this evolved a melodic death metal sound, typified by Swedish bands such as In Flames and Dark Tranquillity and Finland's Children of Bodom and Kalmah.[citation needed]
[edit] Black metal
The first wave of black metal emerged in Europe in the early and mid-1980s, led by Britain's Venom, Denmark's Mercyful Fate, Switzerland's Hellhammer and Celtic Frost, and Sweden's Bathory. By the late 1980s, Norwegian bands such as Mayhem and Burzum were heading a second wave. Black metal varies considerably in style and production quality, although most bands emphasize shrieked and growled vocals, highly distorted guitars frequently played with rapid tremolo picking, a "dark" atmosphere and intentionally lo-fi production, with ambient noise and background hiss. Satanic themes are common in black metal, though many bands take inspiration from ancient paganism, promoting a return to pre-Christian values. Numerous black metal bands also "experiment with sounds from all possible forms of metal, folk, classical music, electronica and avant-garde." Darkthrone drummer Fenriz explains, "It had something to do with production, lyrics, the way they dressed and a commitment to making ugly, raw, grim stuff. There wasn't a generic sound."
By 1990, Mayhem was regularly wearing corpsepaint; many other black metal acts also adopted the look. Bathory inspired the Viking metal and folk metal movements and Immortal brought blast beats to the fore. Some bands in the Scandinavian black metal scene became associated with considerable violence in the early 1990s, with Mayhem and Burzum linked to church burnings. Growing commercial hype around death metal generated a backlash; beginning in Norway, much of the Scandinavian metal underground shifted to support a black metal scene that resisted being co-opted by the commercial metal industry. According to former Gorgoroth vocalist Gaahl, "Black Metal was never meant to reach an audience.... [We] had a common enemy which was, of course, Christianity, socialism and everything that democracy stands for."
By 1992, black metal scenes had begun to emerge in areas outside Scandinavia, including Germany, France, and Poland. The 1993 murder of Mayhem's Euronymous by Burzum's Varg Vikernes provoked intensive media coverage. Around 1996, when many in the scene felt the genre was stagnating, several key bands, including Burzum and Finland's Beherit, moved toward an ambient style, while symphonic black metal was explored by Sweden's Tiamat and Switzerland's Samael. In the late 1990s and early 2000s, Norway's Dimmu Borgir brought black metal closer to the mainstream, as did Cradle of Filth, which Metal Hammer calls England's most successful metal band since Iron Maiden.
[edit] Power metal
During the late 1980s, the power metal scene came together largely in reaction to the harshness of death and black metal. Though a relatively underground style in North America, it enjoys wide popularity in Europe, Japan, and South America. Power metal focuses on upbeat, epic melodies and themes that "appeal to the listener's sense of valor and loveliness." The prototype for the sound was established in the mid- to late 1980s by Germany's Helloween, which combined the power riffs, melodic approach, and high-pitched, "clean" singing style of bands like Judas Priest and Iron Maiden with thrash's speed and energy, "crystalliz[ing] the sonic ingredients of what is now known as power metal."
Traditional power metal bands like Sweden's HammerFall, England's DragonForce, and Florida's Iced Earth have a sound clearly indebted to the classic NWOBHM style. Many power metal bands such as Florida's Kamelot, Finland's Nightwish, Italy's Rhapsody of Fire, and Russia's Catharsis feature a keyboard-based "symphonic" sound, sometimes employing orchestras and opera singers. Power metal has built a strong fanbase in Japan and South America, where bands like Brazil's Angra and Argentina's Rata Blanca are popular.
Closely related to power metal is progressive metal, which adopts the complex compositional approach of bands like Rush and King Crimson. This style emerged in the United States in the early and mid-1980s, with innovators such as Queensrÿche, Fates Warning, and Dream Theater. The mix of the progressive and power metal sounds is typified by New Jersey's Symphony X, whose guitarist Michael Romeo is among the most recognized of latter-day shredders.
[edit] Doom and gothic metal
Emerging in the mid-1980s with such bands as California's Saint Vitus, Maryland's The Obsessed, Chicago's Trouble, and Sweden's Candlemass, the doom metal movement rejected other metal styles' emphasis on speed, slowing its music to a crawl. Doom metal traces its roots to the lyrical themes and musical approach of early Black Sabbath and Sabbath contemporaries such as Blue Cheer, Pentagram, and Black Widow. The Melvins have also been a significant influence on doom metal and a number of its subgenres. Doom emphasizes melody, melancholy tempos, and a sepulchral mood relative to many other varieties of metal.
The 1991 release of Forest of Equilibrium, the debut album by UK band Cathedral, helped spark a new wave of doom metal. During the same period, the doom-death fusion style of British bands Paradise Lost, My Dying Bride, and Anathema gave rise to European gothic metal, with its signature dual-vocalist arrangements, exemplified by Norway's Theatre of Tragedy and Tristania. New York's Type O Negative introduced an American take on the style.
In the United States, sludge metal, mixing doom and hardcore, emerged in the late 1980s—Eyehategod and Crowbar were leaders in a major Louisiana sludge scene. Early in the next decade, California's Kyuss and Sleep, inspired by the earlier doom metal bands, spearheaded the rise of stoner metal, while Seattle's Earth helped develop the drone metal subgenre. The late 1990s saw new bands form such as the Los Angeles–based Goatsnake, with a classic stoner/doom sound, and Sunn O))), which crosses lines between doom, drone, and dark ambient metal—the New York Times has compared their sound to an "Indian raga in the middle of an earthquake".
[edit] New fusions: 1990s and early 2000s
The era of metal's mainstream dominance in North America came to an end in the early 1990s with the emergence of Nirvana and other grunge bands, signaling the popular breakthrough of alternative rock. Grunge acts were influenced by the heavy metal sound, but rejected the excesses of the more popular metal bands, such as their "flashy and virtuosic solos" and "appearance-driven" MTV orientation.
Glam metal fell out of favor due not only to the success of grunge, but also because of the growing popularity of the more aggressive sound typified by Metallica and the post-thrash groove metal of Pantera and White Zombie. A few new, unambiguously metal bands had commercial success during the first half of the decade—Pantera's Far Beyond Driven topped the Billboard chart in 1994—but, "In the dull eyes of the mainstream, metal was dead." Some bands tried to adapt to the new musical landscape. Metallica revamped its image: the band members cut their hair and, in 1996, headlined the alternative musical festival Lollapalooza founded by Jane's Addiction singer Perry Farrell. While this prompted a backlash among some long-time fans, Metallica remained one of the most successful bands in the world into the new century.
Like Jane's Addiction, many of the most popular early 1990s groups with roots in heavy metal fall under the umbrella term "alternative metal." Bands in Seattle's grunge scene such as Soundgarden, credited as making a "place for heavy metal in alternative rock", and Alice in Chains were at the center of the alternative metal movement. The label was applied to a wide spectrum of other acts that fused metal with different styles: Faith No More combined their alternative rock sound with punk, funk, metal, and hip hop; Primus joined elements of funk, punk, thrash metal, and experimental music; Tool mixed metal and progressive rock; bands such as Fear Factory and Ministry began incorporating metal into their industrial sound, and vice versa, respectively; and Marilyn Manson went down a similar route, while also employing shock effects of the sort popularized by Alice Cooper. Alternative metal artists, though they did not represent a cohesive scene, were united by their willingness to experiment with the metal genre and their rejection of glam metal aesthetics (with the stagecraft of Marilyn Manson and White Zombie—also identified with alt-metal—significant, if partial, exceptions). Alternative metal's mix of styles and sounds represented "the colorful results of metal opening up to face the outside world."
In the mid- and late 1990s came a new wave of U.S. metal groups inspired by the alternative metal bands and their mix of genres. Dubbed "nu metal", bands such as P.O.D., Korn, Papa Roach, Limp Bizkit, Slipknot, and Linkin Park incorporated elements ranging from death metal to hip hop, often including DJs and rap-style vocals. The mix demonstrated that "pancultural metal could pay off." Nu metal gained mainstream success through MTV rotation and Ozzy Osbourne's 1996 introduction of Ozzfest, which led the media to talk of a resurgence of heavy metal. In 1999, Billboard noted that there were more than 500 specialty metal radio shows in the U.S., nearly three times as many as ten years before. While nu metal was widely popular, traditional metal fans did not fully embrace the style. By early 2003, the movement's popularity was on the wane, though some bands associated with nu metal, such as System of a Down retained substantial followings.
[edit] Recent trends: mid–late 2000s
Metalcore, an originally American hybrid of thrash metal and hardcore punk, emerged as a commercial force in the mid-2000s. It is rooted in the crossover thrash style developed two decades earlier by bands such as Suicidal Tendencies, Dirty Rotten Imbeciles, and Stormtroopers of Death. Through the 1990s, metalcore was mostly an underground phenomenon. By 2004, melodic metalcore—influenced as well by melodic death metal—was popular enough that Killswitch Engage's The End of Heartache and Shadows Fall's The War Within debuted at numbers 21 and 20, respectively, on the Billboard album chart. Bullet for My Valentine, from Wales, broke into the top 5 in both the U.S. and British charts with Scream Aim Fire (2008). In recent years, metalcore bands have received prominent slots at Ozzfest and the Download Festival. Lamb of God, with a related blend of metal styles, hit the Billboard top 10 in 2006 with Sacrament. The success of these bands and others such as Trivium, which has released both metalcore and straight-ahead thrash albums, and Mastodon, which plays in a progressive/sludge style, has inspired claims of a metal revival in the United States, dubbed by some critics the "New Wave of American Heavy Metal."
The term "retro-metal" has been applied to such bands as England's The Darkness and Australia's Wolfmother and Airbourne. The Darkness's Permission to Land (2003), described as an "eerily realistic simulation of '80s metal and '70s glam," topped the UK charts, going quintuple platinum. One Way Ticket to Hell... and Back (2005) reached number 11. Wolfmother's self-titled 2005 debut album had "Deep Purple-ish organs," "Jimmy Page-worthy chordal riffing," and lead singer Andrew Stockdale howling "notes that Robert Plant can't reach anymore." "Woman," a track from the album, won for Best Hard Rock Performance at the 2007 Grammy Awards. Slayer's "Eyes of the Insane" won for Best Metal Performance in 2007; their "Final Six" won the same award in 2008. Metallica took the honor in 2009 for "My Apocalypse".
In continental Europe, especially Germany and Scandinavia, metal continues to be broadly popular. Well-established British acts such as Judas Priest and Iron Maiden continue to have chart success on the continent, as do a range of local groups. In Germany, Western Europe's largest music market, several continental metal bands placed multiple albums in the top 20 of the charts between 2003 and 2009, including the long-running German thrash metal band Kreator, Finnish melodic death metal act Children of Bodom, Norwegian symphonic extreme metal group Dimmu Borgir, and two power metal bands, Germany's Blind Guardian and Sweden's HammerFall. The Swedish melodic death metal act In Flames took both Come Clarity (2006) and A Sense of Purpose (2008) to number 6 in Germany; each album topped the Swedish charts.

Summary:
Heavy metal (often referred to simply as metal) is a genre of rock music that developed in the late 1960s and early 1970s, largely in the United Kingdom and the United States. With roots in blues-rock and psychedelic rock, the bands that created heavy metal developed a thick, massive sound, characterized by highly amplified distortion, extended guitar solos, emphatic beats, and overall loudness. Heavy metal lyrics and performance styles are generally associated with masculinity and machismo.
The first heavy metal bands such as Led Zeppelin, Black Sabbath and Deep Purple attracted large audiences, though they were often critically reviled, a status common throughout the history of the genre. In the mid-1970s Judas Priest helped spur the genre's evolution by discarding much of its blues influence; Motörhead introduced a punk rock sensibility and an increasing emphasis on speed. Bands in the New Wave of British Heavy Metal such as Iron Maiden followed in a similar vein. Before the end of the decade, heavy metal had attracted a worldwide following of fans known as "metalheads" or "headbangers".
In the 1980s, glam metal became a major commercial force with groups like Mötley Crüe. Underground scenes produced an array of more extreme, aggressive styles: thrash metal broke into the mainstream with bands such as Metallica and Megadeth, while other styles like death metal and black metal remain subcultural phenomena. Since the mid-1990s, popular styles such as nu metal, which often incorporates elements of grunge and hip hop; and metalcore, which blends extreme metal with hardcore punk, have further expanded the definition of the genre.


[edit] Realisation of the potential
In January 2006 the total installed electrical generating capacity from all forms of renewable energy was less than 2 GW, about a fifth of the total electrical production. By January 2007 wind power capacity, which has been growing rapidly, reached 1 GW capacity, and the total for renewables had grown to over 2.3 GW. By August 2009 wind power capacity was a fraction short of 1.5 GW and total renewables capacity had reached over 3.1 GW. Renewables are now contributing over 19% of total electrical production, and about 4% of all energy usage. It should be borne in mind that electricity production is only part of the overall energy use budget. In 2002, Scotland consumed a total of 175 Terawatt-hours (TWh) of energy in all forms, some 2% less than in 1990. Of this, only 20% was consumed in the form of electricity by end users, the great majority of energy utilised being from the burning of oil (41%) and gas (36%).
Scotland also has significant quantities of fossil fuel deposits, including 62.4% of the EU's proven reserves of oil, 12.5% of the EU's proven reserves of gas and 69% of UK coal reserves. Nonetheless, the Scottish Government has set ambitious targets for renewable energy production. In 2005 the aim was for 18% of Scotland's electricity production to be generated by renewable sources by 2010, rising to 40% by 2020. In 2007 this was increased to 50 per cent of electricity from renewables by 2020, with an interim target of 31 per cent by 2011. The following year new targets to reduce overall greenhouse gas emissions by 80% by 2050 were announced and then confirmed in the 2009 Climate Change Delivery Plan. Maf Smith, director of the Sustainable Development Commission in Scotland said "Governments across the world are shying away from taking the necessary action. The Scottish Government must be commended for its intention to lead the way".
An important reason for this ambition is growing international concern about human-induced climate change. The Royal Commission on Environmental Pollution's proposal that carbon dioxide emissions should be reduced by 60% was incorporated into the UK government's 2003 Energy White Paper. The 2006 Stern Review proposed a 55% reduction by 2030. The recent Intergovernmental Panel on Climate Change's Fourth Assessment Report has further increased the profile of the issue.
[edit] Wind power
Wind power is a renewable technology and produces no greenhouse gases during operation, although inevitably some are produced during construction and transport. The precise amounts involved are a matter of controversy. Manufacturers typically state that carbon emissions are 'paid back' within 3–18 months of production, but recent research claims that turbines located on peat bogs create incidental emissions that may increase this to 8 years or more.
Wind turbines are the fastest growing of the renewable energy technologies in Scotland. Most turbines in the EU produce electricity at an average of 25% of their rated maximum power due to the intermittency of wind resources, but Scotland's wind regime provides average of 40% or higher on the west and northern coasts. A small wind farm on Shetland with five Vestas V47 660�kW turbines recently achieved a world record of 58% capacity over the course of a year.
There are now numerous large on-shore power stations including Black Law Wind Farm rated at over 96 MW, Hadyard Hill Wind Farm, which is the first wind farm in the UK able to generate over 100 MW, and Whitelee Wind Farm, a 322 MW project that is the largest onshore wind farm in Europe. Nevertheless the siting of turbines has become a controversial issue amongst those concerned about the value of natural landscapes.
It is estimated that 11.5 GW of onshore wind potential exists, enough to provide 45 TWh of energy. More than double this amount exists on offshore sites where mean wind speeds are greater than on land. The total offshore potential is estimated at 25 GW, which although more expensive to install, could be enough to provide almost half the total energy used in Scotland. The first offshore turbines are operated by Talisman Energy, who have erected two large machines 25�kilometres (13�nmi) offshore adjacent to the Beatrice oilfield. These turbines are 88�metres (289�ft) high with the blades 63�metres (207�ft) long and have a capacity of 5 MW each, making them amongst the largest in the world.
Plans to harness up to 4.8 GW of the potential in the inner Moray Firth and Firth of Forth were announced in January 2010. Moray Offshore Renewables and SeaGreen Wind Energy were awarded development contracts by the Crown Estate as part of a UK-wide initiative.
[edit] Wave power
Various systems are under development at present aimed at harnessing the enormous potential available for wave power off Scotland's coasts. Pelamis Wave Power (previously Ocean Power Delivery) are an Edinburgh-based company whose Pelamis system has been tested off Orkney and Portugal. These devices are 150�metres (492�ft) long, 3.5�metres (11.5�ft) diameter floating tubes which capture the mechanical action of the waves. Future wave farm projects could involve an arrangement of interlinked 750�kW machines connected to shore by a subsea transmission cable.
Another approach is used by the LIMPET 500 (Land Installed Marine Power Energy Transformer) energy converter installed on the island of Islay by Wavegen Ltd. It is a shore-based unit and generates power when waves run up the beach, creating pressure inside an inclined oscillating water column. This in turn creates pneumatic power which drives twin 250�kW the generators. Islay LIMPET was opened in 2001 and is the world's first commercial scale wave-energy device. The manufacturers are now developing a larger system in the Faroe Islands.
Funding for the UK's first wave farm was announced by the Scottish Executive on 22 February 2007. It will be the world's largest, with a capacity of 3 MW generated by four Pelamis machines at a cost of over 4 million pounds. The funding is part of a new £13 million funding package for marine power projects in Scotland that will also support developments to Aquamarine's Oyster and Ocean Power Technology's PowerBuoy wave systems, AWS Ocean Energy's sub-sea wave devices, ScotRenewables' 1.2 MW floating rotor device, Cleantechcom's tidal surge plans for the Churchill barriers between various Orkney islands, the Open Hydro tidal ring turbines, and further developments to the Wavegen system proposed for Lewis as well as a further £2.5 million for the European Marine Energy Centre (EMEC) based in Orkney. This is a new Scottish Executive-backed research facility that has installed a wave testing system at Billia Croo on the Orkney mainland and a tidal power testing station on the nearby island of Eday. At the official opening of the Eday project the site was described as "the first of its kind in the world set up to provide developers of wave and tidal energy devices with a purpose-built performance testing facility."
The Siadar Wave Energy Project was announced in 2009. This is a 4 MW system to be built by npower Renewables and Wavegen, 400 metres off the shore of Siadar Bay, in Lewis. In early 2010 two areas were identified for substantial offshore wind development, in the Moray Firth basin and outer Firth of Forth. Shortly afterwards the Government earmarked eleven sites they expected to benefit from the construction of up to 8,000 offshore turbines by 2020. These included Campbeltown and Hunterston, four sites previously used for offshore oil fabrication at Ardersier, Nigg Bay, Arnish and Kishorn and five east coast locations from Peterhead to Leith.
[edit] Tidal power
Unlike wind and wave, tidal power is an inherently predictable source. However the technology is in its infancy and numerous devices are in the prototype stages. Today it is known that a tall tubular tower with three blades attached to it is the typical profile of a wind turbine, but twenty-five years ago there were a wide variety of different systems being tested. This is the current situation with regard to tidal power. Some systems capture energy from the tides in a vertical direction. The tide comes in and raises the water level in a basin. As the tide lowers the water in the basin is discharged through a turbine. Tidal stream power captures energy from the flow of tides, usually using underwater plant resembling a small wind turbine. To date the only installed tidal power plant of any size is the 240�MW rated barrage scheme at the Rance Estuary in Brittany, which has been operating successfully for more than 25 years, although there are a number of other much smaller projects around the world. An example is Marine Current Turbines SeaGen 1.2�MW device at Strangford Lough in Northern Ireland, which is the first commercial scale tidal turbine in the world.
The Pentland Firth between Orkney and mainland Scotland has been described as the "Saudi Arabia of tidal power" and may be capable of generating up to 10 GW. In March 2010 a total of ten sites in the area, capable of providing an installed capacity of 1.2 GW of tidal and wave generation were leased out by the Crown Estates. Several other tidal sites with considerable potential exist in the Orkney archipelago. Tidal races on the west coast at Kyle Rhea between Skye and Lochalsh, the Grey Dog north of Scarba, the Dorus Mòr off Crinan and the Gulf of Corryvreckan also offer significant prospects.
[edit] Hydro-electric power
Scotland has 85% of the UK's hydro-electric energy resource, much of it developed by the North of Scotland Hydro-Electric Board in the 1950s. The "Hydro Board", which brought "power from the glens", was a nationalised industry at the time although it was privatised in 1989 and is now part of Scottish and Southern Energy plc.
Numerous remote straths were flooded by these schemes, many of the largest of which involved tunneling through mountains as well as damming rivers. Emma Wood, the author of a study of these pioneers wrote:
Current capacity is 1.33 GW and includes major developments such as the 120 MW Breadalbane scheme and the 245 MW Tummel system. It is estimated that little more than another 0.3 GW remains available to develop. There is further potential for new pump storage schemes that would work well with intermittent sources of power such as wind and wave. Examples include the 440 MW Ben Cruachan and 300 MW Falls of Foyers schemes. The 100 MW Glen Doe project, currently under construction and Scotland's largest civil engineering project, is the first large scale scheme in Scotland for almost fifty years but is likely to be one of the last of its kind.
There is certainly further potential for small-scale run of the river local schemes such as the existing one in Knoydart and planned for Kingussie, but the total effect of such schemes, although important locally, will be tiny on a national basis. The production of hydro electricity has a long history in Scotland but given that the available catchment areas have practically all been exploited it is unlikely that there will be scope for the further development of significant amounts of new hydro generation.
[edit] Biofuels
[edit] Biodiesel
Various biodiesel schemes exist at present, and as with most renewables, interest is growing in the subject. Westray Development Trust operate a biodiesel vehicle fueled by the residual vegetable oils from the Orkney archipelago fish and chip outlets. On a larger scale Argent Energy's plant in Motherwell recycles tallow and used cooking oil to produce 50 million litres of biodiesel per annum.
A major benefit of biodiesel is lower carbon emissions, although the energy balance of liquid biofuels is a matter of controversy. Research is being undertaken into converting rapeseed oil into biodiesel, and the European biofuels directive intends to ensure that 5.75% Europe's transport fuel comes from renewable sources by 2010. However, there is only enough used vegetable oil in the UK to contribute 0.38% of current road fuel demand and if all the arable land in the UK were turned over to biofuel crops this would still only satisfy 22% of the existing requirement for road transport. Serious concerns regarding the ethics of growing biodiesel in developing countries and importing the fuel to Europe have been raised on the grounds that they may replace much needed food crops. Converting any mainstream transport system to a renewable one also involves the conundrum that for consumers to use it the infrastructure must be in place, but high levels of use may be required to finance the infrastructure. Developments are thus slow at present and renewably powered vehicles very much the exception.
Due to the relatively short growing season for sugar producing crops, ethanol is not commercially produced as a fuel in Scotland at present. However there are encouraging developments in cellulosic decomposition that might enable grass or tree crops to be used to this end in future and which may prove to have lower net carbon emissions than other production techniques.
[edit] Biogas, anaerobic digestion and landfill gas
Biogas, or landfill gas, is a biofuel produced through the intermediary stage of anaerobic digestion consisting mainly of 45–90% biologically produced methane and carbon dioxide. In early 2007 a thermophilic anaerobic digestion facility was commissioned in Stornoway in the Western Isles. The Scottish Environment Protection Agency (SEPA) and the Renewable Energy Association are also leading the way towards the establishment of a digestate standard to facilitate the use of solid outputs from digesters on land. Anaerobic digestion and mechanical biological treatment facilities have been planned at a number of other locations in Scotland, such as Westray.
It has been recognised that biogas (mainly methane) – produced from the anaerobic digestion of organic matter – is potentially a valuable and prolific feedstock. It is estimated that 0.4 GW of generating capacity might be available from agricultural waste in Scotland. The Scottish Executive and SEPA has funded seven small scale farm trial plants with the British anaerobic digestion company Greenfinch in Southwest Scotland. Landfill sites have the potential for a further 0.07 GW with sites such as the Avondale Landfill in Falkirk already utilising their potential.
[edit] Solid biomass
Wood fuel almost certainly exceeds hydroelectric and wind as the largest source of renewable energy at present. Scotland's forests, which currently make up 60% of the UK resource base, could provide up to 1 million tonnes of wood fuel per annum. The biomass energy supply in Scotland could reach 450 MW or higher in coming years, (predominantly from wood), with power stations requiring 4,500–5,000 oven dry tonnes per annum per megawatt of generating capacity. The energy company E.ON has constructed a 44 MW biomass power station at Lockerbie using locally sourced crops while the smaller but not insignificant EPR Westfield power plant in Fife produces 9.8 MW of output using chicken litter as fuel. The Forestry Commission are developing a Scottish Biomass Action Plan in conjunction with the Scottish Executive, and the latter is expected to provide a £7.5 million grant scheme to support biomass energy. There is growing demand for automatic wood pellet boilers which can be as convenient to use as conventional central heating systems, and which may be cheaper to run as well as being carbon neutral.
There is also local potential for energy crops such as short-rotation willow or poplar coppice, miscanthus energy grass, agricultural wastes such as straw and manure, and forestry residues. These crops could provide 0.8 GW of generating capacity.
[edit] Micro systems
The Energy Savings Trust has estimated that micro-generation could provide a significantly increased proportion of the UK's electricity demand by 2050 although only a fraction of this would come from renewable sources. The current Scottish output is negligible. In May 2006 the then Communities Minister Malcolm Chisholm launched a Planning Advice Note aimed at promoting micro-renewables. Small-scale 'wind2heat' projects, which use wind turbines to power electrical storage heaters directly, have proven to be successful in remoter rural areas; as have various other local schemes such as air source heat pumps.
Whisky distilleries may have a locally important part to play. Caithness Heat and Power have announced plans to tackle fuel poverty in Wick by utilising a wood chip CHP scheme in partnership with the Old Pulteney Distillery. On the island of Islay, a swimming pool is heated using waste heat from the Bowmore distillery. In Edinburgh, Tynecastle High School, due to be completed in 2010, will be heated by waste heat from the neighbouring North British Distillery. In 2009 the Diageo Cameron Bridge distillery announced plans for a £65�million facility to generate energy from the spent "wash" created in the manufacturing process, which will aim to replace 95% of the plan's existing fossil fuel use.
There are also a growing number of Micro hydro systems on smaller watercourses, especially in more remote rural locations.
[edit] Solar energy
Despite Scotland's relatively low level of sunshine hours, solar thermal panels can work effectively as they are capable of producing hot water even in cloudy weather. The technology was developed in the 1970s and is well-established with various installers in place such as Solar Power Scotland of Montrose, although AES Solar based in Forres (who provided the panels for the Scottish Parliament building) are Scotland's only manufacturer.
There are few examples of photovoltaic panels, which generate electricity, in Scotland as the price is not currently competitive. The introduction of Feed-In Tariffs in April 2010 will shorten the payback period on the cost of a PV installation, making solar PV a competitive form of renewable generation. The largest installation in Scotland is a 21 kWp system at the Sir E. Scott secondary school in Tarbert, Harris. The UK's practicable resource is estimated at 7.2 TWh per annum, which in the Scottish context is the approximate equivalent of 70 MW or less of installed capacity.
The "road energy system" uses water pipes buried beneath a layer of tarmac. In the summer, the dark asphalt is heated by the sun which in turn heats the water in the pipes. This water can be stored in an underground aquifer and the heat extracted in winter using a heat pump. The system can be used to warm or cool down roads, keeping them ice-free and/or preventing softening due to overheating. Alternatively, the stored energy can be used for cooling buildings. The system was developed in the Netherlands and has been licensed by Ullapool-based Invisible Energy Systems, who have installed the technology in their car park.
[edit] Geothermal energy
Geothermal energy is obtained by tapping the heat of the earth itself. Most systems in Scotland provide heating through a ground source heat pump which brings energy to the surface via shallow pipe works. An example is the Glenalmond Street project in Shettleston, which uses a combination of solar and geothermal energy to heat 16 houses. Water in a coal mine 100�metres (328�ft) below ground level is heated by geothermal energy and maintained at a temperature of about 12 °C (54 °F) throughout the year. The warmed water is raised and passed through a heat pump, boosting the temperature to 55�°C (131�°F), and is then distributed to the houses providing heating to radiators.
Although the pumps may not be powered from renewable sources, up to four times the energy used can be recovered. Installation costs can vary from £7,000 to £10,000, and grants may be available from the Scottish Community and Householders Renewables Initiative operated by Community Energy Scotland for domestic properties up to a maximum of £4,000. Perhaps up to 7.6 TWh of energy is available on an annual basis from this source.
[edit] Other means of reducing carbon emissions
It is clear that if carbon emissions are to be reduced, a combination of increased production from renewables and decreased consumption of energy in general and fossil fuels in particular will be required. On the latter front, Gordon Brown, the then UK Chancellor of the Exchequer, announced in November 2006 that within a decade all new houses would have to be 'zero carbon'. A variety of other options exist, most of which may affect development of renewable technologies even if they are not means of producing energy from renewable sources themselves.
[edit] Other renewable options
Various other ideas for renewable energy in the early stages of development, such as ocean thermal energy conversion, deep lake water cooling, and blue energy, have received little attention in Scotland, presumably because the potential is so significant for less speculative technologies.
[edit] Carbon offsetting
Carbon offsetting involves individuals or organisations compensating for their use of fossil fuels by making payments to projects that aim to neutralise the effect of these carbon emissions. Although the idea has become fashionable, the theory has received serious criticism of late.
Nonetheless, a credible option may be to plant trees within the local bioregion and maintain the forest on a permanent basis, thus locking up carbon produced by burning fossil fuels. In British growing conditions this method can compensate for carbon at a rate of 200 tonnes per square kilometre (0.89�tons/acre) planted over a 100 year period. Thus a 4-square-kilometre (988-acre) plantation could uptake 200 tonnes (220�tons) of carbon over twenty-five years. This is the equivalent of 10,000 tonnes (11,000�short tons) of carbon dioxide. The weaknesses of the approach include uncertainty as to whether the planting might have occurred anyway and who, in the future, will ensure permanence. However, there is likely to be a greater level of credibility inherent in a nearby and visible scheme than in a far-distant one.
[edit] Challenges and opportunities offered by non-renewables
The following technologies are means of reducing the effect of carbon emissions and form an important aspect of the energy debate in Scotland and are included here for completeness. Their effect is likely to influence the future direction of commercial renewable energy, but they are not renewable forms of energy production themselves.
Carbon sequestration: Also known as carbon capture and storage, this technology involves the storage of carbon dioxide (CO2) that is a by-product of industrial processes through its injection into oil fields. It is not a form of renewable energy production, but it may be a way to significantly reduce the effect of fossil fuels whilst renewables are commercialised. It may also be an intermediate step towards a 'hydrogen economy' (see below), which could either enable further renewable development or conceivably out-compete it. The technology has been successfully pioneered in Norway but is still a relatively untried concept.
'Clean coal' technology: It is has been estimated that it will be 2020 to 2025 before any commercial-scale clean coal power stations (coal-burning power stations with carbon capture and sequestration) are widely adopted. Moreover, some have criticised the clean coal approach and it is at best a means of ameliorating carbon emissions. It is not a form of renewable energy production, although like carbon sequestration it offers a significant commercial challenge to renewable developments. In 2009 a licence to test underground coal gassification technology in Fife was granted to Thornton New Energy. However, a plan to build a new "clean coal" power station at Hunterston collapsed in 2009 after financial backing was withdrawn.
Nuclear power: Renewable energy as a concept generally excludes nuclear power although this stance has been challenged.
Incineration: There is a successful waste-to-energy incineration plant at Lerwick in Shetland which burns 22,000 tonnes (24,250�tons) of waste every year and provides district heating to over 600 customers. Although such plants generate carbon emissions through the combustion of the biological material and plastic wastes (which derive from fossil fuels), they also reduce the damage done to the atmosphere from the creation of methane in landfill sites. This is a much more damaging greenhouse gas than the carbon dioxide the burning process produces, although other systems which do not involve district heating may have a similar carbon footprint to straightforward landfill degradation.
[edit] Hydrogen
Although hydrogen offers significant potential as an alternative to hydrocarbons as a carrier of energy, neither hydrogen itself nor the associated fuel cell technologies are sources of energy in themselves. Nevertheless, the combination of renewable technologies and hydrogen is of considerable interest to those seeking alternatives to fossil fuels. There are a number of Scottish projects involved in this research, supported by the Scottish Hydrogen & Fuel Cell Association (SHFCA).
The PURE project on Unst in Shetland is a ground-breaking training and research centre which uses a combination of the ample supplies of wind power and fuel cells to create a wind hydrogen system. Two 15�kW turbines are attached to a 'Hypod' fuel cell, which in turn provides power for heating systems, the creation of stored liquid hydrogen and an innovative fuel-cell driven car. The project is community-owned and part of the Unst Partnership, the community's development trust.
In the Western Isles a plan to enable a £10 million waste management plant into a hydrogen production facility was announced in June 2006. The Council have also agreed to purchase hydrogen-fuelled buses and hope the new plant, which will be constructed in partnership with the local Hydrogen Research Laboratory, will supply island filling stations and houses and the industrial park at Arnish.
ITI Energy is a company with the aim of funding Research and Development programmes in the energy sector. It is a division of ITI Scotland, which also includes a life sciences and digital media division. ITI Energy has attracted the Alterg project, a French company that is developing technology for the cost-effective storage of hydrogen.
In July 2008 the SHFCA announced plans for a "hydrogen corridor" from Aberdeen to Peterhead. The proposal involves running hydrogen powered buses along the A 90 and is supported by Aberdeenshire Council and the Royal Mail. The economics and practical application of hydrogen vehicles are currently being investigated by the University of Birmingham in England.
The "Hydrogen Office" in Methil aims to demonstrate the benefits of improved energy efficiency and renewable and hydrogen energy systems.
[edit] Local vs national concerns
A significant feature of Scotland's renewable potential is that the resources are largely distant from the main centres of population. This is by no means coincidental. The power of wind, wave and tide on the north and west coasts and for hydro in the mountains makes for dramatic scenery, but sometimes harsh living conditions. W. H. Murray described the Hebrides as "the Isles on the Edge of the Sea where men are welcome—if they are hard in body and in spirit tenacious."
This happenstance of geography and climate has created various tensions. There is clearly a significant difference between a renewable energy production facility of modest size providing an island community with all its energy needs, and an industrial scale power station in the same location that is designed to export power to far distant urban locations. Thus, plans for one of the world's largest onshore windfarms on the Hebridean island of Lewis, have generated considerable debate. A related issue is the planned high-voltage Beauly–Denny power line which will bring electricity from renewable projects in the north and west to the cities of the south. The matter went to a public inquiry and has been described by Ian Johnston of The Scotsman as a "battle that pitches environmentalists against conservationists and giant energy companies against aristocratic landowners and clan chiefs". In January 2010 Jim Mather, the Energy Minister, announced that the project would be going ahead, notwithstanding the more than 18,000 objections received.
There is considerable support for community-scale energy projects. For example, Alex Salmond, First Minister of Scotland, has stated that "we can think big by delivering small" and aspires to have a "million Scottish households with access to their own or community renewable generation within ten years". The John Muir Trust has also stated that "the best renewable energy options around wild land are small-scale, sensitively sited and adjacent to the communities directly benefiting from them", although even community-owned schemes can prove controversial.
A related issue is the position of Scotland within the United Kingdom. It has been alleged that UK transmission pricing structures are weighted against the development of renewables in Scotland, a debate which highlights the contrast between the sparsely populated north of Scotland and the highly urbanised south and east of England. Although the ecological footprints of Scotland and England are similar the relationship between this footprint and the biocapacities of the respective countries are not. Scotland's biocapacity (a measure of the biologically productive area) is 4.52 global hectares (gha) per head, some 15% less than the current ecological effect. In other words, with a 15% reduction in consumption, the Scottish population could live within the productive capacity of the land to support them. However, the UK ecological footprint is more than three times the biocapacity, which is only 1.6 gha head, amongst the lowest in Europe. Thus, to achieve the same end in the UK context, consumption would have to be reduced by about 66%.
The developed world's economy is presently very dependent on inexpensive 'point-source' fossil fuels. Scotland, as a relatively sparsely populated country with significant renewable resources, is in a unique position to demonstrate how the transition to a low-carbon, widely distributed energy economy may be undertaken. A balance will need to be struck between supporting this transition and providing exports to the economies of densely populated regions in the Central Belt and elsewhere, as they seek their own solutions. The tension between local and national needs in the Scottish context may therefore also play out on the wider UK and European stage.
[edit] Promotion of renewables
Growing national concerns regarding "peak oil" and climate change have driven the subject of renewable energy high up the political agenda. Various public bodies and public-private partnerships have been created to develop the potential. The Forum for Renewable Energy Development in Scotland, (FREDS) is a partnership between industry, academia and Government aimed at enabling Scotland to capitalise on its renewable energy resource. The Scottish Renewables Forum is an important intermediary organisation for the industry, hosting the annual Green Energy Awards. Community Energy Scotland provides advice, grant funding and finance for renewable energy projects developed by community groups. Aberdeen Renewable Energy Group (AREG) is a public-private partnership created to identify and promote renewable energy opportunities for businesses in the north-east. In 2009 AREG formed an alliance with North Scotland Industries Group to help promote the North of Scotland as an "international renewable energy hub".
The Forestry Commission is active in promoting the biomass potential. The Climate Change Business Delivery Group aims to act as a way for businesses to share best practice and address the climate change challenge. Numerous universities are playing a role in supporting energy research under the Supergen programme, including fuel cell research at St Andrews, marine technologies at Edinburgh, distributed power systems at Strathclyde and biomass crops at the UHI Millennium Institute's Orkney College.
[edit] Recent events
New data appears on a regular basis and milestones in 2007-9 include the following.
In February 2007 the commissioning of the Braes of Doune wind farm took the UK renewables installed capacity up to 2 GW. Total Scottish capacity at October 2007 was 1.13 GW from 760 turbines and increased to 1.3 GW by September 2008 and 1.48 GW by August 2009. The Robin Rigg 180 MW wind farm in the Solway Firth, Scotland first large offshore wind farm, is expected to commence production in the summer of 2009.
Also during 2007 Scottish and Southern Energy plc in conjunction with the University of Strathclyde began the implementation of a 'Regional Power Zone' in the Orkney archipelago. This ground-breaking scheme (that may be the first of its kind in the world) involves 'active network management' that will make better use of the existing infrastructure and allow a further 15MW of new 'non-firm generation' output from renewables onto the network. Heat and Power Ltd. of Westray are involved in developing an innovative digestor system that is being trialled at Tuquoy farm. Designed by Sam Harcus and Colin Risbridger, it is capable of handling up to 1,500 tonnes of feedstock per annum. Scottish & Southern Energy have been asked to provide for an export capacity of 40kWe. The aim is to help move the farm towards being powered by 100% renewable energy.
In January 2008 it was reported that Professor Graeme Walker of the University of Abertay is leading a project aimed at using grain that is a by-product of whisky distilling as a biofuel.
In February 2008 plans to build a 10MW prototype tidal energy plant in the Pentland Firth were announced by Tocardo Tidal Energy Ltd. of Wick. Production is expected to commence in 2009. The following September, Scottish Power announced plans for two tidal projects in the same area, pending successful tests of a £6 million prototype.
In January 2009 the government announced the launch of a "Marine Spatial Plan" to map the potential of the Pentland Firth and Orkney coasts and agreed to take part in a working group examining options for an offshore grid to connect renewable energy projects in the North Sea to on-shore national grids.
In July 2009 a new study called "The Power of Scotland Renewed" was published. Its findings indicated that the country could meet all its electricity needs by 2030 without the requirement for either nuclear or fossil fuel powered installations.
[edit] Summary of Scotland's resource potential
Table notes
a. ^ Note on 'installed capacity' and 'potential energy'. The former is an estimate of the maximum productive output of a given technology or individual generation station at a single point in time. The latter takes into account the likely intermittency of energy supply and is a measure of output over a period of time. Thus, for example, individual wind turbines may have a 'capacity factor' of between 15% and 45% depending on their location, with a higher capacity factor giving a greater potential energy output for a given installed capacity. The 'potential energy' column is thus an estimate based on a variety of assumptions including the installed capacity. Although 'potential energy' is in some ways a more useful method of comparing the current output and future potential of different technologies, using it would require cumbersome explanations of all the assumptions involved in each example, so installed capacity figures are generally used.
b. Table notes and sources:

Summary:
The production of renewable energy in Scotland is an issue that has come to the fore in technical, economic, and political terms during the opening years of the 21st century. The natural resource base for renewables is extraordinary by European, and even global standards. In addition to an existing installed capacity[a] of 1.3 Gigawatts (GW) of hydro-electric schemes, Scotland has an estimated potential of 36.5 GW of wind and 7.5 GW of tidal power, 25% of the estimated total capacity for the European Union and up to 14 GW of wave power potential, 10% of EU capacity. The renewable electricity generating capacity may be 60 GW or more, considerably greater than the existing capacity from all Scottish fuel sources of 10.3 GW.
Much of this potential remains untapped, but continuing improvements in engineering are enabling more of the renewable resources to be utilised. Fears regarding "peak oil" and climate change have driven the subject high up the political agenda and are also encouraging the use of various biofuels. Although the finances of many projects remain either speculative or dependent on subsidies, it is probable that there has been a significant, and in all likelihood long-term change, in the underpinning economics.
In addition to planned increases in both large-scale generating capacity and microsystems using renewable sources, various related schemes to reduce carbon emissions are being researched. Although there is significant support from the public, private and community-led sectors, concerns about the effect of the technologies on the natural environment have been expressed. There is also an emerging political debate about the relationship between the siting, and the ownership and control of these widely distributed resources.