Technical-economic analysis of Gas Insulated Lines

T abajo de Fin de G ado Ti ulación G ado Ingenie ía en Tecnologías Indus iales Technical-economic analysis o Gas Insula ed Lines MEMORIA TFG Au o : Juan Ramón Llo ca O olá Di ec o : O iol Gomis Codi ec o : Ma c Cheah Con oca o ia: Julio 2018 2 Abs ac The inc easing elec ic demand shows he need o a g id ein o cemen which is going o be accomplished in he ollowing yea s. These new lines will ha e o be designed ocusing on e iciency and sus ainabili y in o de o imp o e he pe o mance o he powe g id. These new pa ame e s gi e us he oppo uni y o alk abou Gas Insula ed Lines (GIL) due o i s low ansmission losses, and high ansmission capaci y [1]. This p ojec p esen s a echnical-economic analysis o GIL, o app oxima e he o al cos o a GIL in as uc u e wi h i s singula echnical a angemen s, bo h ini ial in es men cos s and long e m cos s due o he ope a ion. To accomplish i all cos componen s ha e been app oached as unc ion o nominal alues o a GIL p ojec ; o his eason a s udy has been done o each single cos componen o ela e he echnical solu ion wi h cos s. A numbe o pa ame e s (such as geome ic measu es, mass o insula o gas, conduc o esis ance, capaci ance o induc ance) o he ins alla ion ha e been ob ained by s a is ic eg essions based on da a om a ailable sou ces. These pa ame e s ha e been needed o come up wi h he ins alla ion p ice. In addi ion a case s udy is p esen ed, whe e di e en echnologies a e compa ed in e ms o cos . The objec i e is o show di e ences in he p ice o each componen be ween he di e en echnology a angemen s o he gi en case. I can be seen ha he e a e signi ican di e ences be ween echnologies in he ini ial in e sion cos and he li e-long ope a ion cos . Wi h he case s udy which is e e ed o a egula ins alla ion, can be seen which is he cheapes elec ic solu ion and which is he highe cos e icien echnology, which leads o a low p ice in es men and ope a ing expenses. 3 Gas Insula ed Lines. Technical-economic analysis Con en Abs ac ......................................................................................................................................... 2 Lis o ac onyms ............................................................................................................................ 5 1. In oduc ion .......................................................................................................................... 6 1.1 Fu u e powe supply sys em ......................................................................................... 6 1.2 O e head lines, Unde g ound Cables and Gas Insula ed Lines (GIL) ............................ 7 1.2.1 O e head lines.............................................................................................................. 7 1.2.2 Unde g ound cables .............................................................................................. 8 1.2.3 GIL .......................................................................................................................... 8 1.3 In e es o Gas Insula ed Lines .................................................................................... 10 1.4 Objec i es .................................................................................................................... 11 2. GIL echnical backg ound and pa desc ip ion .................................................................. 13 2.1 Desc ip ion o GIL echnology componen s ................................................................ 13 2.1.1 Insula ion Gas ...................................................................................................... 13 2.1.2 Conduc o and enclosu e se -up ......................................................................... 14 2.2 GIL laying op ions ........................................................................................................ 17 2.2.1 Abo e-g ound ins alla ion ................................................................................... 18 2.2.2 T ench-laid........................................................................................................... 19 2.2.3 Tunnel-laid ........................................................................................................... 19 2.2.4 Di ec ly bu ied ..................................................................................................... 21 3. Cos modelling ..................................................................................................................... 23 3.1 Tool desc ip ion ........................................................................................................... 24 3.2 GIL a iables and modelling ........................................................................................ 24 3.3 Cos dependency on ansmission capaci y and ou ing ............................................ 26 3.3.1 Ou e enclosu e cos dependency ...................................................................... 26 3.3.2 Conduc o cos dependency ............................................................................... 29 3.3.3 Disconnec ing, compensa o uni s and male and emale sliding cos dependency ......................................................................................................................... 31 3.4 Cos dependency on laying me hods .......................................................................... 32 3.4.1 Di ec ly bu ied laying cos s ................................................................................. 33 3.4.2 T ench laying cos s .............................................................................................. 35 3.4.3 Tunnel laying cos s .............................................................................................. 37 3.4.4 Abo e g ound ins alla ions ................................................................................. 42 3.5 Cos dependency on Gas quan i y .............................................................................. 43 3.5.1 𝐒𝐒𝐒𝐒𝐒𝐒 + 𝐍𝐍𝐍𝐍 ............................................................................................................. 43 3.5.2 𝐂𝐂𝐒𝐒𝐂𝐂𝐂𝐂 ................................................................................................................... 45 4 3.6 Assembly, es ing and anspo cos .......................................................................... 46 3.7 Li e-long cos s .............................................................................................................. 47 3.7.1 Powe losses and powe ansmission capaci y educ ion due o eac i e powe cos calcula ion .................................................................................................................... 47 3.7.2 Ope a ion and main enance cos ........................................................................ 58 3.8 Dis ance non-dependen cos s. .................................................................................. 59 3.8.1 GIS (GIL e mina ions) ......................................................................................... 59 3.9 P ojec launch and build con ingency ......................................................................... 60 4 Case s udy ........................................................................................................................... 61 4.1 GIL cos s udy and sensi i i y ............................................................................................ 62 4.1.1 Cos s udy o GIL .................................................................................................. 64 4.1.2 Sensi i i y s udy o GIL ........................................................................................ 67 4.2 O e head lines ............................................................................................................ 70 4.2.1 Ini ial in es men cos s. Fixed cos s .................................................................... 70 4.2.2 Va iable cos s ...................................................................................................... 71 4.3 Unde g ound lines ....................................................................................................... 76 4.3.1 Ini ial in es men cos ......................................................................................... 77 4.3.2 Va iable cos s ...................................................................................................... 78 4.4 Case s udy esul s discussion ............................................................................................ 80 5. Conclusion ........................................................................................................................... 83 Re e ences ................................................................................................................................... 84 5 Gas Insula ed Lines. Technical-economic analysis Lis o ac onyms OHL O e head Lines GIL Gas Insula ed Lines GIS Gas Insula ed Swi che HVAC High Vol age Al e na ing Cu en HVDC High Vol age Di ec Cu en UHV Ul a High Vol age PTC Powe T ansmission Cos AC Al e na ing Cu en DC Di ec Cu en XLPE C oss-linked polye hylene 6 1. In oduc ion 1.1 Fu u e powe supply sys em Nowadays he en i e wo ld is claiming o a solu ion o he pollu ion p oblems ye isible in many di e en plane ca as ophes. These wo ies ha e been come h ough in he 2015 Uni ed Na ions Clima e Change Con e ence, held in Pa is 2015. Howe e he powe consump ion is inc easing, wha will ha e as a consequence he sea ch o new ene gy sou ces. To accomplish EU’s a ge o 20% sha e o ene gy om enewable ene gies [2], some changes mus be in oduced in he powe gene a ion sys em. I means, enewable ene gy sou ces a e undoub edly going o be he u u e in he elec ic powe ma ke . No mally hese sou ces end o be a away om he p incipal load cen es and need o be connec ed wi h long and wide elec ic ne s. This ac o and he inc easing elec ic demand lead o hink abou an op imized in e na ional long-dis ance high-powe ansmission ne wo k. Nowadays in he Eu opean Union he e a e weak in e na ional connec ions, which a e wo king in case o powe misma ch be ween p oduc ion and demand. In o de o ein o ce he pe cen age o enewable elec ic consump ion, a la ge scale ul a-high ol age (UHV) o Al e na ing Cu en (AC) o Di ec Cu en (DC) sys em mus be inse ed. This long ansmission sys em is mo i a ed by he need o aking p o i o enewable ene gy independen ly whe e i is p oduced. As an example, g ea enewable ene gy sou ces a e loca ed in he no he n seas in Eu ope o wind powe p oduc ion. Reliable c oss bo de connec ions a e needed o boos no only he in eg a ion o enewable ene gies, bu also o ensu e secu i y in ene gy supply. Fo hese easons coun ies in Eu opean Union mus ha e by 2020 a leas a 10% o o al powe capaci y in e connec ion wi h o he coun ies [3]. In conclusion, High Vol age Al e na ing Cu en (HVAC) long-dis ance ansmission sys ems a e needed o ensu e secu i y and eliabili y in he u u e in e na ional g id. Besides i is aking g ea impo ance he concep o ne e iciency which b ings us o he s udy o Gas Insula e Lines (GIL) because o i s low ansmission losses and low capaci i e and induc i e compensa ion needs [4]. 7 Gas Insula ed Lines. Technical-economic analysis 1.2 O e head lines, Unde g ound Cables and Gas Insula ed Lines (GIL) An in oduc ion o O e head Lines (OHL) and Unde g ound Cables and GIL is done in o de o compa e OHL and Unde g ound Cables wi h GIL in e ms o o al cos s in a case s udy done in chap e 4. 1.2.1 O e head lines Nowadays OHL is he mos commonly used sys em o UHV AC connec ions be ween powe s a ions and big consume s; o da e, hey a e he mos cos -e ec i e me hod o HVAC ansmission [5]. An OHL ou e consis s o conduc o s in o m o cables hanging om owe s. The ou e design is a balance be ween he size and dis ance o he s uc u e owe s [5]. Also his decision is aken in o accoun wi h he conside a ions o o he aspec s as isual and en i onmen al impac . In Spain he OHL ansmission g id (UHV ne wo k) wo ks be ween 220 and 400 kV and has a o al dis ance o mo e han 40.000 km. In Figu e 1 an OHL owe is shown. The main cha ac e is ics o he ins alla ion shown in his pic u e a e: i has go wo ci cui s wi h h ee- ou conduc o s pe phase; conduc o s o he same ci cui and he same phase o m a beam; conduc o s o di e en phases a e sepa a ed a s ipula ed dis ances o a oid elec ic haza d; conduc o s o ming a beam a e sepa a ed be ween hem wi h insula o s, as well as conduc o s wi h he owe . In Figu e 1 is shown a ypical OHL owe , i is he same one as used in he case s udy. Figu e 1. OHL owe . (Da a sou ce: [6]) 8 1.2.2 Unde g ound cables Unde g ound cables a e used ac oss he wo ld along wi h OHLs. The main eason o using his sys em is o OHL space and en i onmen al es ic ions, o example en i onmen al p o ec ed a eas o high densi y popula ed a eas. Unlike OHL, unde g ound cables canno use ai as he insula ing medium; as ai can ans e hea om he conduc o away much be e han cables wi h cable insula ion. The e o e, la ge cables a e needed o ansmi he same powe as OHL. The p obabili y o using eac i e compensa ion uni s is ela ed o ope a ion ol age, conduc o size and ci cui leng h; i is impo an o ema k ha cables do ha e highe induc ance and capaci ance a es. In Figu e 2 i can be seen a no mal ound unnel wi h h ee cables co esponding pe haps o di e en phases. Figu e 2 Unde g ound cable unnel. (Da a sou ce: [13]) 1.2.3 GIL Gas Insula ed lines a e he sa e al e na i e o o e head lines. The low impac on he landscape and he high ansmission capaci y make GIL a sui able ansmission sys em o ace u u e g id ein o cemen s. Pe haps i is he p ice he i s disad an age in on o o he ansmission sys ems; howe e de elopmen s on he ield can ca y cos educ ions. GIL sys em can handle la ge amoun s o powe , e en mo e han O e head Lines (OHL), due o i s bigge conduc o a ea. The ol age ange o GIL co e s high ol ages om 100kV o 800kV, a es whe e mos o UHV lines wo k on. As he a ea is in e sely p opo ional o he esis ance[7], he ansmission losses o GIL a e much lowe han o e head ansmission lines. GIL is he bes op ion o high ol ages due o high powe a ing. The GIL concep was i s ly de eloped in he 1960s, i is known as he GIL 1s gene a ion, which wo ked only wi h SF6. Fu he in es iga ion and es s did p o e ha mixing SF6 and N2 (GIL 2nd gene a ion) would educe ins alla ion cos s and gas handling di icul y. 9 Gas Insula ed Lines. Technical-economic analysis Since 1970 mo e han 150 GIL p ojec s ha e been ins alled wo ldwide, all o hem p o ing i s ou s anding pe o mance capabili y [8]. GIL ins alla ion can be done in dedica ed enches, abo e-g ound o in unnels. Also, he e is he possibili y o ins alling GIL lines in sha ing s uc u es such as ailway unnels, highway ne wo ks o e en gas lines. Nowadays GIL a e based on N2 + SF6 ubula conduc o echnology. As i can be seen in Figu e 3, i consis s o a cen al aluminium conduc o wi h a ypical elec ical c oss sec ion o up o 5300 mm2 [9], inside an ou e enclosu e pipe. The conduc o lies on he cen e o he ou e enclosu e, es ing on cas esin insula o s. The enclosu e p o ides a solid mechanical and elec ical con ainmen o he sys em. The ully encapsula ed enclosu e p o ec s GIL agains ou side in luences and p o ides a ee main enance sys em. The space be ween he ou e enclosu e and he conduc o is illed wi h he gas mix u e (N2 + SF6) which nowadays his mix u e is a ound 20% SF6 and 80% N2. This mix u e has been since many yea s es ed o p o e i s insula ion eliabili y. Figu e 3 GIL layou . (Da a sou ce: [4]) The high secu i y ha GIL is able o o e di e en ia es GIL om o he ansmission sys ems which expose he g id e ec i i y o some clima e haza d. The cu en gas mix u e used gi es e y good elec ical insula ion p ope ies, which enable lexible ou e planning. In addi ion, his mix u e is non- oxic, ine , non- lammable, non-co osi e and long- ime s able. Howe e , SF6 is a g eenhouse gas which may be highly ha m ul o he en i onmen , his is he main eason o doing u he in es iga ion on al e na i e gases. A he end o i s li e cycle, all ma e ials and he gas mix u e being used can be 100% ecycled. Some ypical echnical da a o GIL is shown in Table 1 [10]: 16 Figu e 5. Compensa o uni . (Da a sou ce: [9]) 2.1.2.4 Conical and suppo insula o s Conical and suppo insula o s made o epoxy cas esin ha e been de eloped o ix he inne conduc o o he enclosu e and o sepa a e he gas compa men s. They mus gi e he p ope mechanical and empe a u e esis ance as well as he discha ge acking wi hs andabili y. 2.1.2.5 S aigh uni In e e ence o he di e en pa s indica ed in Figu e 4, he enclosu e (1), whe e he inne conduc o (2) is ixed by conical insula o s (4) and on suppo insula o s (5). The longi udinal he mal expansion o he conduc o is adjus ed by he sliding con ac sys em (3a male sliding con ac , 3b emale sliding con ac ). A s aigh uni has a leng h up o 120 m made by di e en joined sec ions (each sec ion o 12-18 m leng h) welded oge he by an o bi al welding machine [11]. The s aigh uni only has an insula o posi ioned inside he enclosu e pipe (one each 120 m); see Figu e 6. Figu e 6. S aigh uni . (Da a sou ce: [9]) 2.1.2.6 Angle uni The bending adius is a basic p ojec planning pa ame e o design he ou ing and o al leng h o he GIL ins alla ion. Angle uni s a e designed be ween 0-90˚. Due o hei cos s angle uni s 17 Gas Insula ed Lines. Technical-economic analysis a e only used when smalle han 400 m adius a e needed. Unde mos condi ions o landscape, no angle uni s a e needed, because he elas ic bending is enough o ollow he con ou . An angle uni consis s o a single-phase enclosu e made o cas aluminium alloy. In he enclosu e (1) he inne conduc o (2) is ixed by a conical insula o (4) and on suppo insula o s (5). Angle uni is connec ed o s aigh uni by o bi al welding. In Figu e 7 is shown a ypical angle uni Figu e 7. Angle uni . (Da a sou ce [9]) 2.1.2.7 Disconnec ing uni Disconnec ing uni s used in unde g ound sha s o sepa a e gas compa men s and o connec high- ol age es ing equipmen o he commissioning o GIL. In case i is equi ed o connec gas compa men s be o e and a e he disconnec ing uni , a bypass can be se . Disconnec ing uni s a e loca ed a dis ances o 1000 o 1500 m. In Figu e 8 is shown a disconnec ing uni . Figu e 8. Disconnec ing uni . (Da a sou ce: [9]) 2.2 GIL laying op ions Di e en laying op ions de ine di e en cos s, he e o e i is impo an o ge o know he main di e ences be ween each laying op ion and e en o look o al e na i es, such as sha ing s uc u es. 18 Due o GIL signi ican p ope ies, GIL ha e been se in many di e en layou s, o sol e complex ou ing. GIL ha e been ins alled in s aigh e ical, a ound buildings abo e and belowg ound, and e en se pen ine ou ings wi hou angle uni s. 2.2.1 Abo e-g ound ins alla ion Today, mo e han 50% [11] o GIL ins alla ion a e sol ed by using abo e-g ound in as uc u e. Cos s o his laying sys em a e lowe han o he op ions because he e a e less ins alla ion equi emen s. Fu he mo e, in his case isual inspec ions a e easily done. This laying op ion needs a s eel s uc u e o ix i on g ound; his s uc u e is in no mal condi ions si ua ed be ween 100-120 [11] m dis ance. Some he mal condi ions mus be conside ed when designing he s uc u e; o example in cold coun ies whe e snow o ice can come o be an addi ional load o e en wind which causes bending o ces. The ype o holding s uc u es can depend on some es ic ions which a y he dis ance o loo . Laying close o g ound needs smalles and simple s eel s uc u es; bu laying high abo e-g ound (such as 5-8 m heigh [11]) allows a ic below he GIL bu needs o mo e complex s eel s uc u es. These s eel s uc u es a e hen ixed o g ound wi h conc e e socke s. In Figu e 9 a e shown ypical s eel s uc u es. Figu e 9.Typical s eel s uc u es. (Da a sou ce: [9]) As he enclosu e aluminium is exposed o ai , he oxygen c ea es an oxide laye , which a oids co osion. Only wa e a e much ime o cons an exposu e, can co ode aluminium, as i begins a eac ion ha is able o des oy aluminium sel -p o ec ion. To a oid his unwan ed impac , p o ec ion is needed by coa ing hose a eas o wa e pene a ion. Fo his coa ing an ex e nal HDPE pipe is used. 19 Gas Insula ed Lines. Technical-economic analysis I is demons a ed ha p ice o he High Densi y Polye hylene HDPE coa ing is negligible as a 400 KV GIL has mo e han 40 kg/m o me al [13]. F om he same e e ence, he plas ic coa ing pipes weigh 9 kg/m [13]. P ice o plas ic is much lowe han p ice o me al; also plas ic p o ec ion is only needed o hose a eas whe e he e is cons an exposi ion o wa e . Fo his eason he use o plas ic coa ing won’ be accoun ed in he o al cos o he ins alla ion. 2.2.2 T ench-laid The easons o he use o ench-laid ins alla ions a e no mally when c ossing o he ins alla ions in a powe plan . I is a easible solu ion when abo e-g ound solu ions a e no possible. The laying s uc u es o ench-laid GIL a e e y simila o he abo e-g ound ins alla ions as bo h su e he same mechanical s ess. The e o e, s eel s uc u e dis ances a e he same. T enches a e usually made o p e ab ica ed conc e e panels, whe e he s eel s uc u e ixes he GIL. Al hough being mo e expensi e han abo e-g ound ins alla ions, a e s ill e y accessible and isual con ol can be p ope ly done. In Figu e 10 is shown a ench laid sys em. Figu e 10. T ench laid sys em. (Da a sou ce: [9]) In enches layou , he same aspec s abou co osion mus be aken in o accoun . The ench needs a us ul d ainage and dewa e ing sys em o a oid cons an con ac o wa e o he enclosu e pipe. In case i canno be assu ed, pain ing is needed and con ol and main enance a e equi ed. 2.2.3 Tunnel-laid Tunnel laid ins alla ion, al hough being he mos expensi e laying sys em, hey gi e he oppo uni y o se a non- isible om abo e and accessible powe ansmission sys em. Besides, 20 no co osion p o ec ion is needed i i can be ensu ed ha no wa e can pene a e in o he unnel. This laying sys em is mainly used when he di ec ly bu ied laying is no possible. Tunnel cos s depend much on he way hey a e buil : om close- o- he -su ace unnels, wa e igh , o deep-unde g ound unnels. In each case a singula s udy mus be done o op imize p ojec cos s. Nowadays p e ab ica ed s uc u al elemen s a e educing cons uc ion du a ion and cons uc ion cos s. • Open T ench-Laid Tunnel (squa ed unnel sec ion) is he sui able op ion when close- o- he-su ace unnels can be buil . In his case a ench is opened om he g ound and unnel conc e e segmen s, which can be p e ab ica ed o p oduced on-si e, a e assembled. Finally, hey a e co e ed wi h soil (minimum co e ing heigh 1 m). The GIL sys ems lies in a small space o 2,5 m2 o wo GIL sys ems, which lea es enough space o a walkway in he cen e o 0,8 m wide. In Figu e 11 can be seen a no mal sec ion and dis ibu ion o a squa ed unnel. Figu e 11. Open ench-laid unnel. (Da a sou ce: [9]) • The Bo ed Tunnels a e ound and usually ha e a diame e o 3-4 m o wo GIL sys ems. Highly au oma ized machines can dig unde g ound o cons uc bo ed unnels; high de elopmen in his Bo ed Tunnels does p o ide highe speed, accu acy and lowe cos s (s ill being e y high). In unnel-laid ins alla ion GIL lays ixed o he unnel walls. The laying o ces a e simila o abo e- g ound ins alla ions. In bo h cases s eel s uc u es hold he s aigh uni laid on sliding ixing poin s o allow he mal expansion o he enclosu e. The laying s uc u es o unnel-laid GIL a e si ua ed no mally a dis ances o 28 m. 21 Gas Insula ed Lines. Technical-economic analysis 2.2.4 Di ec ly bu ied The di ec ly bu ied laying sys em o GIL is ge ing highe impo ance in GIL o unde g ound powe ansmission. This is he powe ansmission op ion o long-dis ance applica ions, p e e ably o open landscape ac oss he coun y; i o e s an economical and as laying solu ion. In Figu e 12 is shown a ypical h ee phase Di ec ly Bu ied layou . The laying me hods a e adap ed o oil and gas pipeline laying echniques, as hey ha e been o long p o ed in long-dis ance supply o ene gy: • When he GIL ins alla ion is di ec ly bu ied in o he soil, he ou e enclosu e needs an ou e passi e co osion p o ec ion made o polye hylene o polyp opylene coa ings. The join a ea, p oduced by an o bi al welding join ing machine, has a special coa ing o p o ec he weld. Fo he same eason explained in chap e 2.2.1, hei p ice is no accoun ed in he cos s udy. • The su ounding soil needs o be ee o s ones, o p e en GIL pipe om being damaged; he minimum co e age soil is 1 m. The back ill ma e ial is ypically a sand and clay mix u e so as o keep wa e in he soil o imp o e hea conduc i i y. No mally back ill ma e ials a e used a e il e ing hem o ocks and s ones. In he a eas whe e GIL has been laid no digging execu ions can’ be done. Fu he mo e, no all ees can be plan ed. • In o de o ge his minimum heigh (1 m) o a single-phase and h ee-phase GIL a 2-2,5 m dep h ench is dug. In case o h ee-phase elec ical ansmission, he dis ance be ween he enclosu e pipes is 0,5-0,8 m. This dis ance depends on he mal and accessibili y a ai s. The expec ed wid h o a h ee-phase GIL is 4,5-5 m. All his igu es ha e been gi en o a 500 mm enclosu e pipe diame e . In Figu e 12 a ypical layou can be seen; he a es indica ed in Figu e 10 may a y due o di e ences in echnical a angemen s. • In his laying me hod he s aigh uni s do no ha e o be ixed in he g ound o a oid longi udinal mo emen ; in he soil he GIL is ancho ed due o i s weigh , so no addi ional compensa ion elemen s a e needed. • Disconnec ing uni s a e placed in conc e e sha s. The disconnec ing uni s allow access o GIL; in hese sha s measu emen senso s such as p essu e moni o ing a e loca ed, o con ol GIL wo king condi ions. As i is indica ed in he Disconnec ing Uni sec ion (2.1.2.7), each sha mus be si ua ed each 1000-1500 m. 22 Figu e 12. Th ee-phase di ec ly bu ied sec ion. (Da a sou ce: [12]) In e ms o o ces, di ec ly bu ied GIL pipes, ha e o ace he weigh o he soil laying on he pipe. Tha means ha a leas 1 m heigh and 0.5 m wid h sec ion o soil. In addi ion, in case o ha ing a ic abo e hem o snow, u he loads ha e o be suppo ed by he enclosu e pipe. 23 Gas Insula ed Lines. Technical-economic analysis 3. Cos modelling The main aim o his hesis is o de elop a ool o calcula ing o al GIL in as uc u e cos s, om ini ial in es men o powe losses and li e-long cos s. No e ha o he associa ed cos s, such as g id ein o cemen s o insu ance cos s a e ou o he scope. In o de o simpli y calcula ion i has been dispa aged he ansien beha iou , and only ocused on he s a iona y s a e. This chap e explains i s ly how does he ool wo ks, secondly which a e he equa ions ha ela e he main pa ame e s o he ins alla ion wi h he cos , he echnical conside a ions employed, and unc ions and a iables used o de elop he ool. The me hodology used in his economic cos s udy conside s a g ea a ie y o asse ypes, o be able o p edic cos s o any di e en layou . Tha means ha he cos is calcula ed in e e ence o he ype o laying, he ou ing (numbe o angle uni s, e c) and he dimensions o he in as uc u e depending on echnical pa ame e s. The p ice o ma e ials used is also a pa ame e o be in oduced in he sys em o imp o e he quali y o he cos app oxima ion. GIL sys ems ha e go many di e en echnical speci ica ions a iables and i ems ha in luence g ea ly in he inal cos and make he cos es ima ion ex emely complex. In o de o simpli y cos calcula ion, he cos componen s ha e been sepa a ed in o: 1. Fixed cos s ela ed o ini ial in es men • Pipe and conduc o • Ci il wo ks • Gas • T anspo and ins alla ion • Rou ing (angle uni s, disconnec ing uni s) • GIS + T ans o me s + Tes ing + Reac i e powe compensa ion • P ojec con ingency • P ojec managemen 2. Va iable cos s • Powe losses • Cos o educed powe ansmission capaci y due o eac i e powe • Losses in he compensa ion uni • Ope a ion and main enance 24 Finally, in he cos app oxima ion o a h ee-phase enclosed GIL i has been always s udied he case which each phase conduc o is inside a di e en pipe, and no he case which all conduc o s a e inside he same enclosu e pipe. 3.1 Tool desc ip ion The ool wo ks wi h he ollowing p inciples: i s , use s in oduce he main da a ega ding GIL echnology (see chap e 3.2). The ool de e mines he cos s o he en i e p ojec e u ning he o al cos and also he cos associa ed o each componen . An app oach o minimize he numbe o inpu s has been done whene e i has been possible. Howe e in he sea ch o be ealis ic and do an accu a e p edic ion, use s, do ha e o in oduce some eal in o ma ion such as cu en p ices o ma e ials used in he in as uc u e (me al, gas p ices), o some da a e e ed o he in as uc u e. 3.2 GIL a iables and modelling Rega ding GIL in as uc u e cos calcula ion, many a iables a e signi ican ly dependen o he inal cos . To achie e a model o calcula ing he inal cos , i s o all, inpu s and a iables a e needed o p o ide di e en scena ios. The main inpu s used in his ool a e he nominal ol age in kV and he nominal appa en powe ; bu some o he in o ma ion has o be in oduced which is indica ed in Table 2. 25 Gas Insula ed Lines. Technical-economic analysis Table 2. Main a iables. Va iable Uni Nominal appa en powe MVa Nominal ol age kV Li e ime Yea s Discoun a e (pe uni ) To al leng h ( e e ing leng h o ype o laying and soil) m Cos o MW/h €/MWh Single/Th ee phase - Numbe o pa allel uni s - P ice Aluminium ou e enclosu e €/kg P ice Aluminium conduc o €/kg P ice SF6 €/kg P ice N2 €/kg Numbe o ans o me s - Numbe o GIS (Gas insula ed swi che s) - Wi h he nominal ol age (V) and he appa en powe (S), in ensi y (I) pe conduc o can be calcula ed. No e ha in he (1), (2) V is e e ed o he phase- o-phase ol age. • Single phase sys ems: Ss−p = V * I (1) • Th ee phase sys ems S −p= 3 * V √3 * I (2) A numbe o o he pa ame e s no speci ied in Table 2 di ec ly depend on he speci ied a iables used in his ool. When he o al leng h is indica ed hen he numbe o disconnec ing uni s, male and emale sliding, and compensa o uni s is known. Disconnec ing uni s a e si ua ed a dis ances o 1000-1500 m (in he ool is used 1250 m) o sepa a e gas compa men s and connec es ing ha dwa e. Male and emale sliding con ac uni s a e si ua ed each 100 m o cope wi h he mal expansion. Compensa o uni s a e si ua ed a dis ances o 300-400 m (in he ool 32 Figu e 16. Disconnec ing uni , Solid Wo ks design. Sou ce Solid Wo ks. No e ha in case o ha ing mo e han one pipe, he cos is calcula ed by mul iplying he o al numbe o pipes. Rega ding male and emale sliding con ac as hey a e wo pipes one inside he o he , i has no been conside ed a special p ice as no special machining is necessa y unlike angle uni s and disconnec ing uni s. 3.4 Cos dependency on laying me hods Ci il wo k cos s o GIL depend much on he si e, he laying me hod and local condi ions. Op imising he GIL laying and ou ing migh be signi ican in he o al cos o he in as uc u e; o his eason when designing a new ansmission line, i is necessa y o do a p e ious esea ch wo k s udying di e en ou e planning wi h hei di e en laying me hods and ypes o soil, he e o e, aking in o accoun all he condi ionings, o come up wi h he mos sui able solu ion. This hesis assumes ha he ou e and laying me hods a e de ined p e iously in each p ojec and ha his ool only p o ides he necessa y cos s. No e also ha he ou e does in luence he o al cos o main enance and o he a iable cos s as powe losses. 33 Gas Insula ed Lines. Technical-economic analysis Rega ding he pa h, s anda d GIL ins alla ions end o be done close o oads o o he communica i e sys ems, as accessibili y, main enance, join ing and welding he pipes is c ucial o GIL ins alla ion, and o p ice educ ion. 3.4.1 Di ec ly bu ied laying cos s Di ec ly bu ied GIL is gaining impo ance nowadays o unde g ounding a GIL in as uc u e. This laying me hod is a con inuous p ocess and i can co e long dis ances much as e han o he laying me hods like unnels. Ano he ad an age is ha he mal compensa ion elemen s a e no needed because GIL is held in place by he weigh o he soil and ic ion be ween he soil and he pipe. Also no s eel ixing s uc u e is needed. The g ea es di e ence wi h o he laying me hods is ha GIL pipes a e exposed o ex e nal condi ioning wi h pe manen con ac wi h wa e o humidi y, he e o e, he aluminium pipe mus be bounded o a oid co osion. Pipes a e equipped wi h a XLPE ex e nal p o ec i e coa ing. Table 8 gi es a cos app oxima ion on he cos (€/m3) o each ype o soil exca a ion. [21] Table 8. P ices o each ype o e ain Type o e ain Type o machine P ice(€/m3) Disagg ega e (a) Exca a o 4,73 Loose (b) Exca a o 5,67 Compac (c) Exca a o 7,09 Ha d (d) Comp esso 12,29 So ock (e) Comp esso 24,59 Ha d ock ( ) Comp esso 39,34 Now, in o de o calcula e cos s, i is necessa y o es ima e he amoun o soil ha needs o be ex ac ed. In he Figu e 17 can be seen he pa ame e s o exca a ing he ench. Figu e 17. Di ec ly bu ied sec ion. (Da a sou ce: [16]) 34 A eg ession wi h each pa ame e is done o gi e a ela ionship be ween hem and he a ed ol ages ins alled. No e ha pa ame e s J, G, H, F a e om a h ee phase GIL sys em. Impo an , in he ollowing equa ions, V e e s o ol age be ween phase and neu al. Equa ions a e collec ed a he end. -F [19] Table 9. Values o F. Vol age (kV) 145 242 362 420 800 1200 F (m) 0,368 0,457 0,559 0,711 0,813 1,016 -J [19] Table 10. Values o J. Vol age (kV) 145 kV 242kV 362 kV 420 kV 800 kV 1200 kV J (m) 1,27 1,5 1,8 2,28 2,64 3,1 -H [19] Table 11. Values o H. Vol age (kV) 145 kV 242kV 362 kV 420 kV 800 kV 1200 kV J (m) 1,21 1,2 1,2 1,3 1,5 1,6 -G [19] Table 12. Values o G. Vol age (kV) 145 kV 242kV 362 kV 420 kV 800 kV 1200 kV J (m) 0,91 0,91 0,91 0,91 1,07 1,21 Table 13. S a is ic eg ession o he dimensions Equa ion R² F (12) 0,0006V + 0,3464 0,9304 J (13) 0,0017V + 1,207 0,9173 H (14) 0,0004V + 1,1115 0,9420 G (15) 0,0003V + 0,8235 0,9423 35 Gas Insula ed Lines. Technical-economic analysis Whe e; V: ol age phase-phase (kV). Digging cos s a e calcula ed by mul iplying o al cubic m ex ac ed wi h digging p ices, di e encing hem be ween each soil ype: • Single phase sys ems: Cd= n*J/3*H*∑di∗pi i= i=a (16a) • Th ee phase sys ems: Cd= n*J*H*∑di∗pi i= i=a (16b) whe e; J and H: pa ame e s indica ed in Figu e 17 [m]; dx: dis ance o each ype o soil [m]; pi: p ice o exca a ing o each ype o soil [kg/m3]; n: numbe o pa allel uni s. In o de o calcula e digging cos s o single-phase GIL in as uc u e, a simpli ica ion is done, he p ice will be he p ice o a h ee-phase sys em di ided by h ee. In he case o mul iple pa allel h ee-phase sys ems, digging p ice will be calcula ed mul iplying he numbe o pa allel h ee-phase sys ems, wi h he p ice o a single one. 3.4.2 T ench laying cos s The ench laying layou is e y simila o di ec ly bu ied bu soil ex ac ed is no back illed. T enches a e made o conc e e panels. This laying ype is mo e expensi e han abo e-g ound ins alla ions, bu less expensi e han unnels [11]. In his case unlike di ec ly bu ied laying, s eel s uc u es like ubbing hange s, conc e e inse s a achmen s, e c, a e needed o ix he ou e enclosu e pipe o conc e e. They a e si ua ed a dis ances o 100-120 m [22]. P ice o all his s uc u al a achmen s pieces ha e no been in oduced in he calcula ion ool as hey a e insigni ican among he cos o o he componen s like pipes, bu hey can be ound in [23]. In e e ence o [24] he s eel /i on s uc u es cos is a ound 1,91 €/kg. 36 In o de o calcula e cos s, measu es o di e en ol age a es a e showed in Figu e 18, in o de o es ablish a ela ionship be ween hem and ol age. As well as i has been explained in uni 3.4.1 (di ec ly bu ied), he same conside a ions will be aken o single-phase and o pa allel h ee-phase sys ems. In addi ion, a simila o mula used o calcula e he di ec ly bu ied laying sys em cos s is used o calcula e he digging cos s, di e en ia ing he ha dness o he soil. Figu e 18. T ench laying sec ion. Digging cos s is exp essed as: Cd= B*H*∑di∗pi i= i=a (17) whe e; • Th ee phase sys ems: H= 4A+3D and he no mal alue o A is 0,3 m. • Single phase sys ems: H= 2A+D and he no mal alue o A is 0,3 m. B and C: a e pa ame e s ha depend on each p ojec and a e indica ed in Figu e 18. In he cos calcula ion ool hese alues mus be in oduced as a iables. To calcula e he cos o he conc e e pla o ms: • Single phase sys em Cconc e e = p ∗n∗2d ∗(B + C)+ d ∗(4A +3D) (18a) • Th ee phase sys em Cconc e e = p ∗n∗2d ∗(B + C)+ d ∗(2A + D) (18b) whe e; 37 Gas Insula ed Lines. Technical-economic analysis d: dis ance o he ench [m]; D: enclosu e pipe diame e [m] n: numbe o pa allel uni s p: p ice o conc e e panels [€/m2] Being p ice pe squa e me e o he s anda d conc e e panels 17,97 €/m2 [25]: 3.4.3 Tunnel laying cos s Tunnel laying is no mally used when he di ec bu ial ins alla ion in enches is no easible. Tunnels when laid om he op ha e a squa ed o m; no mally his sec ion is used in u al a eas wi h low popula ion densi y. Fo highe densi y a eas ound sec ion unnels a e done as hey a e much deepe han he i s ones. Tunnel laying cos s a e sensi i e o ou e leng h and unnel diame e . I is no ed ha his laying me hod is he mos expensi e one. Dimensions o squa ed and ound unnels wi h wo pa allel GIL sys ems, a e exp essed as unc ion o he ou e enclosu e pipe diame e . The mos ypical a angemen o he unnel laying is h ee phase sys ems [26]. In he unnel laying me hod, ixing s eel s uc u es a e needed, hey a e si ua ed each 28 m [11]. As well as i has been done in he ench laying me hod, he p ice o his s eel s uc u es is no included in he calcula ion ool as he s eel s uc u es may a y in ela ion o he enginee ing p ojec ; u he mo e p ice can a y be ween di e en p o ide s. Fo example a p o ide o his s uc u al objec s is [23]. The mos impo an eason o no conside ing hei cos is ha i is insigni ican among he cos o o he componen s o he GIL in as uc u e. As he e a e h ee di e en unnel op ions, h ee di e en ways o app oaching i s cos s a e explained: 3.4.3.1 Squa ed sec ion unnels Tunnels a e buil in an open ench in segmen s using p e ab ica ed conc e e panels assembled on-si e and hen co e ed wi h soil wi h a co e age heigh o 1 o 2 m. To calcula e cos s i will be conside ed 1,5 m. GIL is hen ixed o he unnel walls. In Figu e 19 is shown wo h ee-phase uni s in a squa ed sec ion unnel. 38 Figu e 19. Squa ed sec ion unnel. (Da a sou ce: [26]) Sec ion S exp essed in m2 o a squa ed sec ion: • Tunnel sec ion o wo pa allel h ee phase sys ems: S= (0,224*2 + 1,128 + 2 *D) * (0,2115*2+2*0,213+3*D) (19a) • Tunnel sec ion o a h ee phase sys em and o single phase sys em: S= (0,224*2 + 1,128 + 2 *D) * (0,2115*2+2*0,213+3*D)/1,5 (19b) whe e; D: diame e o he ou e enclosu e [m]. Cos o squa ed unnels is calcula ed as sum o digging cos and conc e e: 1. Cos o digging • Two pa allel h ee phase sys ems: Cd=(S + (0,224 ∗2 + 1,128 + 2 ∗D)∗1,5)∗l∗p (20a) • A h ee phase sys em o a single phase sys em: Cd=(S + (0,224 ∗2 + 1,128 + 2 ∗D)∗1,5)/1,5 ∗l∗p (20b) whe e; 39 Gas Insula ed Lines. Technical-economic analysis Cd: cos o digging [€]; D: diame e o he ou e enclosu e pipe [m]; l: leng h [m]; p: p ice [€/m3]. P ices o digging o each ype o soil a e indica ed Table 8. 2. Cos o conc e e panels: Being p ice pe squa e me e is 17,97 €/m2 [25]: • Two pa allel h ee phase sys ems: Cconc e e =[2∗(0,224 ∗2 + 1,128 + 2 ∗D)+ 2 ∗(0,2115 ∗2+2∗0,213 + 3 ∗D)]∗ p∗l (21a) • A h ee phase sys em o a single phase sys em: Cconc e e =[2∗(0,224 ∗2 + 1,128 + 2 ∗D)/1,5 + 2 ∗(0,2115 ∗2+2∗0,213 + 3 ∗ D)]∗p∗l (21b) whe e; Cconc e e: cos o he conc e e panels [€]; D: diame e o he ou e enclosu e pipe [m]; l: leng h [m]; p: p ice [€/m2]. 3.4.3.2 Bo ed unnels: As bo ed unnels a e deep unde g ound, a sha is buil o in oduce he bo ing machine and he p e ab ica ed conc e e segmen s. In Figu e 20 is shown a ypical ound unnel sec ion. 40 Figu e 20. Round sec ion unnel. (Da a sou ce: [13]) The sec ion S o a ound unnel exp essed in m2 o a ound sec ion is calcula ed wi h he ollowing equa ions: • Two pa allel h ee phase sys ems: S = (0,450 + 0,150 ∗ 2 + 0,350 + 3 ∗D ) 2 * π 4 (22a) • A h ee phase sys em o a single phase sys em S = (0,450 + 0,150 ∗ 2 + 0,350 + 3 ∗D ) 2 /1,8* π 4 (22b) whe e; D: diame e o he ou e enclosu e [m]. No ice ha in case o ha ing a single phase o one h ee-phase sys em o al sec ion will be calcula ed by di iding by 1,8 he p e ious sec ion. This numbe has been se aking in o accoun ha enough space is le o main enance wo ks. To come wi h a cos calcula ion model, cos is only es ima ed o he ube ci il wo ks. The me hod used exp esses he cos pe longi udinal me e o he unnel, in e e ence o he a iables RMR index and he exca a ion sec ion (S) [27]. The RMR is an index ha gi es a classi ica ion o he ha dness o he ock being exca a ed. To al cos o unnelling is calcula ed[27]: C unnelling =(83.93 ∗S−148,189 ∗RMR +9578.3)∗l (23) whe e; 41 Gas Insula ed Lines. Technical-economic analysis C unnelling: cos o unnelling [€/m] S: sec ion [m2]; RMR: index; l: leng h [m]. 3.4.3.3 Mul ipu pose unnels An app op ia e way o cos educ ion when unnel laying is necessa y, i is o sha e he s uc u e wi h o he use s. Two di e en p inciples o mul ipu pose unnels can be seen. Fi s ly Round Tunnels, made by a bo ing machine which gi es a ound sec ion o he unnel. Usually, as he loo is needed o be la , he space be ween he oad and he conc e e panels can be used o ix he GIL pipes. This ype o unnels a e shown Figu e 21. Figu e 21 Mul ipu pose unnels. Round Tunnels (Da a sou ce: [22]) Secondly, hose unnels which ha e been cons uc ed in he adi ional building p ocess known as ‘D ill and blas ’. The e is he possibili y o ix he GIL pipes on he oo . This ype o unnels a e shown in Figu e 22. 48 C: equi alen capaci y; L: equi alen induc ance; R: equi alen esis ance; I: in ensi y; Vab: ol age in he load (phase-neu al); P: ac i e powe consumed by he load. In o de o calcula e powe losses and eac i e powe consump ion o gene a ion, he ollowing assump ions ha e been done: • V e phase is 0º. • The appa en powe a he load side is assumed as ull ac i e powe (cos φ =1). To come up wi h powe losses and he eac i e powe in he line, in ensi y lowing by he induc ance, capaci o and esis ance mus be calcula ed. In Figu e 26 he equi alen o The enin is shown as i is used o calcula e ol age in he load Vab (phase-neu al). Knowing V e and Vab we a e able wi h his aluess o calcula e he in ensi y I lowing h ough he equi alen esis ance and induc ance in he pi ci cui (see Figu e 25). Figu e 26. The enin equi alen ci cui . (Da a sou ce: EE ETSEIB) All pa ame e s indica ed in Figu e 26 a e associa ed o he The enin’s heo em. The pa ame e s o he The enin heo em E h and Z h a e calcula ed o p o ide U h=Vab which e e s o he ol age in he load: 1. E h = Vab when no load is connec ed o he ansmission ci cui . (31) 49 Gas Insula ed Lines. Technical-economic analysis 2. Z h which e e s o he equi alen impedance o The enin when he ol age sou ces a e sho -ci cui ed and he in ensi y sou ces a e opened. Z h = −2jXC (−2jXC+jXL+R) −4jXc+jXL+R (32) whe e; Z h: The enin’s impedance [Ω]; R: Resis i e impedance [Ω] ( e e ed o Figu e 25); XC: Capaci i e impedance [Ω] ( e e ed o Figu e 25); XL: Induc i e impedance [Ω] ( e e ed o Figu e 25). Finally he ollowing equa ion is sol ed in o de o ge V2= U h = Vab. Values associa ed o his The enin equa ion a e ela ed o alues shown in Figu e 26. V2 4+ V2 2 �2R hP + 2X hQ−E h2�+�R h2+ X h2�(P2+ Q2)= 0 (33) whe e; R h: Equi alen The enin’s esis ance [Ω] ( e e ed o Figu e 25); X h: Equi alen The enin’s eac i e impedance [Ω] ( e e ed o Figu e 25); P: Powe consumed in he load ( e e ed o Figu e 25); Q: Reac i e powe consumed o gene a ed in he load ( e e ed o Figu e 25). In his case all he a iables a e associa ed o Figu e 26. In o de o calcula e ol age in he load (V2= Vab), i is calcula ed wi h he ollowing equa ion: (34) We ha e o know alues o ZPQ which e e s o he impedance o he load and I h which e e s o he The enin’s in ensi y. Following equa ions a e used o come up wi h he V2 alue. (35) Finally, once ha we know V2 (phase o neu al ol age), i can be calcula ed he in ensi y h ough he esis ance and induc ance in he PI ci cui (Figu e 25). In ensi y is used o calcula e he powe losses in he esis ance due o Joule’s e ec , and o calcula e he eac i e powe 50 consumed in he induc ance. On he o he hand, V2 is used as well as V1=V e o calcula e he capaci i e powe gene a ed in he condensa o . (36) All his calculus a e e e ed o single phase sys ems. In case o h ee phase sys ems i has been used he single phase equi alen by using V e as ol age be ween phase and neu al. Then o calcula e ene gy losses and eac i e powe , he esul s should be mul iplied by 3. 3.7.1.1 Powe losses In o de o come up wi h powe losses alues i is necessa y o know he esis ance pa ame e . The line esis ance depends on he ou e enclosu e diame e and he wall hickness o he ou e enclosu e and conduc o pipe[11], u n, hey depend on he ol age a ing. Ac i e powe ansmission losses a e ela ed o he squa e o he ansmi ed cu en as: Pl= R ∗I2 (37) This alues shown in he p e ious equa ion a e e e ed o Figu e 25. To c ea e he cos calcula ion ool, i has been necessa y o app oxima e esis ance pe phase and m o each ol age a e. Da a om wo di e en bibliog aphic sou ces Table 15 om [19] and Table 16 om [16] ha e been collec ed: Table 15. Resis ance. (Da a sou ce: [19]) Vol age (kV) 138 230 345 500 μΩ/m 26,017 17,257 12,598 9,186 Table 16. Resis ance ( Da a sou ce: [16]) Vol age (kV) 145 / 170 245 / 300 362 420 / 550 800 1200 μΩ/m 18 16 13 11 10 8 In Figu e 27 is shown he s a is ic eg ession be ween esis ance (μΩ/m) and a ed ol age kV. 51 Gas Insula ed Lines. Technical-economic analysis Figu e 27. Resis ance pe m. = 254,16V-0,501 (38) R² = 0,8944 whe e; : esis ance [μΩ/m]; V: ol age [kV]. The powe losses cos is calcula ed as he cos o he ene gy no sold du ing he wo king hou s o he li e- ime pe iod o he GIL in as uc u e. The quan i y o wo king hou s pe yea conside ed a e 8760 h. The ene gy selling p ices ha e been aken by de aul as 50 €/MWh [30]. Depending on he ype o ansmission sys em (single-phase and h ee-phase), yea ly cos o losses a e exp essed as: • Single-phase: Pl =10−6 ∗ ∗I2 (39a) Cos APL =10−12 ∗ ∗I2∗nH ∗Ce∗d (40a) • Th ee phase: Pl = 3 ∗10−6 ∗ ∗I2 (39b) Cos APL =10−12 ∗3∗ ∗I2∗nH ∗Ce∗d (40b) y = 254,16x-0,501 R² = 0,8944 0,00 5,00 10,00 15,00 20,00 25,00 30,00 0,00 200,00 400,00 600,00 800,00 1000,00 1200,00 1400,00 Vol age 52 whe e; Cos APL: cos € powe losses in a yea o wo king GIL sys em [€]; nH: numbe o wo king hou s pe yea : 8760 h [13]; 𝐂𝐂𝐞𝐞: cos o ene gy [€/MWh]; : esis ance pe me e [μΩ/m]; d:dis ance o he line [m]; I: in ensi y [A] see Figu e 25. In o de o p esen he alue o he sum o he annual o al cos s o he powe losses o e he n yea s o he p ojec li e ime, EA, can be ob ained[13]: EA=(1+i)n−1 i(1+i)n∗ Cos APL (41) whe e; n: ins alla ion’s numbe o yea s o li e; i: discoun a e (pe uni ). 3.7.1.2 Powe ansmission capaci y educ ion due o eac i e powe Reac i e powe a e a consequence o he induc ance and capaci ance o he ansmission line. Reac i e powe gene a ed o consumed in a ansmission line educes he o al capaci y o ac i e powe ansmission o a line. Un il now, only AC GIL sys ems ha e been de eloped as a consequence o p oblems in he de elopmen o DC GIL sys ems [11]. In GIL ins alla ions, o e long dis ances o 60-80 km, no eac i e powe compensa ion is equi ed [11]. In his hesis he u iliza ion o compensa o uni s is conside ed; when he a io Q/P>0,2 [13], which P and Q e e o: • P: powe consumed by he load (see Figu e 25). • Q: eac i e powe a he beginning o he GIL in as uc u e, e e ing o he eac i e powe ha is consumed o gene a ed by he GIL ins alla ion, so ha he assump ion done ha in he load he powe is ully ac i e is accomplished. (See Figu e 25) 53 Gas Insula ed Lines. Technical-economic analysis Ne e heless in case he a io Q/P is lowe han 0,2 (no compensa o uni is used) all he eac i e powe consumed o gene a ed in he line is conside ed in he cos calcula ion, as a educ ion o he capaci y o ac i e powe ansmission. Fi s ly, o calcula e he alue o capaci i e powe , da a o capaci ance o di e en GIL p ojec s ha e been ob ained o gi e a ela ionship be ween capaci ance and ol age a es. Capaci ance is exp essed in picoF/m and is e e ed o a single phase. Values a e shown in Table 17 and Table 18. Table 17. Capaci ance. (Da a sou ce: [16]) Vol age (kV) 145 242 362 550 800 1200 pF/m 59,5 52,6 53,1 54,2 45,1 42,7 Table 18. Capaci ance. (Da a sou ce: [19]) Vol age (kV) 138 kV 230 kV 345 kV 500 kV 750 kV pF/m 56,743 46,364 44,500 46,364 42,138 In Figu e 28 is shown he s a is ic eg ession o he capaci ance alue (picoF/m) o each a ed ol age (kV). Figu e 28. Capaci ance. C = -0,0168V + 59,951 (42) R² = 0,7224 whe e; C: capaci ance pe phase and me e [pF/m] y = -0,0168x + 59,951 R² = 0,7224 0 10 20 30 40 50 60 70 0 100 200 300 400 500 600 700 800 900 CAPACITANCE VOLTAGE 54 V: ol age [kV] To calcula e o al capaci ance eac i e powe : • Single phase: Qc=|V|2 Z∗=−4π∗ eq∗c 1012 ∗(|V1∗103|2+|V2∗103|2)∗d (43a) • Th ee phase: Qc= j 3 ∗ 4π∗ eq∗c 1012 ∗(|V1∗103|2+|V2∗103|2)∗d (43b) whe e; Qc: capaci i e powe [VA ]; C: capaci ance pe phase and me e [pF/m]; eq: equency [Hz] (in he ool used he Eu opean equency 50Hz); V: ol age (kV) (see Figu e 25); d: dis ance [m]. Secondly o calcula e he induc i e powe o he conduc o , da a o induc ance om di e en GIL p ojec s a e collec ed o come up wi h a ela ionship be ween induc ance and ol age. Induc ance is exp essed in μH/m and e e ed o a single phase. Values a e shown in Table 19 and Table 20. Table 19. Induc ance Vol age (kV) 138 230 345 500 μH/m 0,196 0,211 0,209 0,209 Table 20. Induc ance Vol age (kV) 145 242 362 550 800 μH/m 0,187 0,211 0,210 0,205 0,247 55 Gas Insula ed Lines. Technical-economic analysis In Figu e 29 is shown he s a is ic eg ession o he induc ance pa ame e (μH/m) ela ed o each a ed ol age. Figu e 29.Induc ance. L = 0,1886e0,0003V (45) R² = 0,6594 whe e; L: induc ance pe me e [μH/m] V: ol age [kV] To calcula e induc ance eac i e powe pe yea : • Single phase: QI= 10−6 ∗ (2 ∗π∗ eq ∗ L ∗I2∗d) (46a) • Th ee phase: QI= 3 ∗10−6 ∗(2 ∗π∗ eq ∗L∗I2∗d) (46b) whe e; Ql: induc i e powe [VA ]; I: cu en lowing in he PI ci cui (see Figu e 25) [A]. The cos ela ed o he educ ion o powe ans e due o eac i e powe is calcula ed in a simila way o he powe losses. This cos is associa ed o he educ ion o he ansmission y = 0,1886e0,0003x R² = 0,6594 0,000 0,050 0,100 0,150 0,200 0,250 0,300 0 100 200 300 400 500 600 700 800 900 INDUCTANCE VOLTAGE INDUCTANCE PER METER (VOLTAGE) [MICROH/M] 56 capaci y, ha means ene gy ha canno be ansmi ed. The cos associa ed o he eac i e powe in he GIL sys em (QI−QC), is app oxima ed by calcula ing he sub ac ion be ween o al cos o ene gy a he beginning o GIL and powe consumed in he load and in he ci cui due o losses (Sgene a o − P − Pl). The powe a he beginning o GIL is calcula ed wi h he ollowing equa ion: Sgene a o = �(P + Pl)2+ (QI−QC)2 (47) Re e ing o cos o educ ion o ansmission capaci y due o he eac i e powe pe yea : Cos RP = �Sgene a o − P − Pl�∗nH ∗Ce (48) whe e; P: o al powe consumed in he load [kW]; Pl: o al powe losses in he GIL in as uc u e [kW] Cos RP: cos o eac i e powe [€/yea ]; nH: numbe o wo king hou s pe yea [h]; 𝐂𝐂𝐞𝐞: cos o ene gy [€/kWh]; In o de o p esen he alue o he sum o he annual o al cos s o e he n yea s o he ci cui li e ime, ER is ob ained[13]: ER=(1+i)n−1 i(1+i)n ∗ Cos RP (49) whe e; i: discoun a e. n: ins alla ion’s numbe o yea s o li e. Finally, o al cos o powe losses and he cos ela ed o educ ion o powe ans e due o eac i e powe is calcula ed as: ET=EA+ ER (50) 3.7.1.3 T ansmission leng h and phase compensa ion 57 Gas Insula ed Lines. Technical-economic analysis The limi ing leng h wi hou he use o phase compensa ion is o high impo ance in o de o calcula e o al cos o he ansmission line. The c i e ia used o de e mine he use o compensa o s is he a io Q/P=0,2 (cosφ=0,98), whe e P e e s o ac i e powe consumed by he load.[26] In case GIL does no need eac i e powe compensa ion (Q/P < 0,2), his eac i e powe can be quan i ied in cos s as he ex a uel needed o be consumed o p oduce he powe ha inally is con e ed in o eac i e powe ; no e ha all his eac i e ene gy ansmi ed ha canno be used, causes an inc ease on he p ice o he ins alla ion. Tha means a powe in as uc u e is designed by a es o ol age and appa en powe . In his i s case as eac i e powe is no compensa ed he in as uc u e mus be o e dimensioned. In case he a io Q/P is g ea e han 0,2 eac i e compensa ion de ices a e used. The e a e wo main op ions, ixed- alue compensa o s, and a iable compensa o s. On he one hand, ixed alue compensa o s, such as shun eac o s a e cheape and occupy less space, bu he compensa ion a es a e ixed. On he o he hand, a iable compensa o s such as STATCOMs (S a ic Synch onous Compensa o ) a e mo e expensi e, bu hey can compensa e exac ly each alue desi ed in each momen . I i is he case o cons an wo king pa ame e s, he a ia ion o he eac i e powe is low. In his case, he compensa ion me hod used is a mix u e o a base cons an compensa ion (shun eac o ) and an addi ional compensa ion capaci y gi en by he a iable compensa ion done by STATCOM. F om [30] is ob ained he cos o a shun eac o and a STATCOM compensa o . • STATCOM: The app oxima e cos is 0,086 M€/MVA . • Shun eac o s The cos o eac o s is se a 0,01 M€/MVA . In o de o calcula e he cos o compensa ion a a io ha accoun s he a ia ion o eac i e powe is in oduced o calcula e he cos o he STATCOM compensa o . Ccompensa ion = 0,01 ∗|q o |+ 0,086 ∗R∗|q o | (51) whe e; Ccompensa ion : cos o he compensa o s [M€]; 64 4.1.1 Cos s udy o GIL In he cos s udy, he cos has been di ided in wo di e en componen s, ini ial in es men (shown in Table 26) and li e-long cos s. 1. Ini ial in es men Table 26. Ini ial in es men Million € €/m €/MVA Pipe + Conduc o 54,7 576,1 22.421,3 Ci il wo ks 5,6 59,0 2.296,2 Gas ( N2 + SF6 ) 88,5 931,6 36.258,1 Rou ing (angle + disconnec ing uni s) 0,3 3,0 117,7 T anspo , ins alla ion es ing 143,5 1.510,8 58.797,1 GIS + Compensa o 9,5 99,6 3.876,4 P ojec con ingency 45,3 477,0 18.565,0 P ojec managemen and launch 40,8 429,3 16.706,9 To al ixed cos s 388,2 4.086,5 159.038,6 I is no ed he impo ance o he aluminium pipes, gas and anspo , ins alla ion and es ing on o al cos . Tha con i ms wha is s a ed in [11] ha a no mal dis ibu ion o he ini ial cos o in es men is 40 % o ma e ials (gas, pipes, angle uni s, and disconnec ing uni s), 40% o ins alla ion, anspo and es ing and inally 20% is o p ojec launch, managemen and enginee ing. In Figu e 32 is shown he ini ial in es men dis ibu ion. 65 Gas Insula ed Lines. Technical-economic analysis Figu e 32. Ini ial in es men . Rema k ha he componen ou ing e e s o hose componen s o he pipes ha a e angle uni s, disconnec ing uni s, male and emale sliding con ac , and compensa o s. 2. Li e-long cos s No e ha his cos s ha e been calcula ed o he whole p ojec li e ime o he line which is conside ed 40 yea s. The discoun a e index is assumed as 0,05. Fu he mo e, as he a io Q/P<0,2 (see chap e 3.7.1.2) he e a e no compensa ion uni s and eac i e powe educes he maximum capaci y o he line. In Figu e 33 is shown he cos dis ibu ion o he a iable cos s, and in Table 28 a e shown all he a iable cos s. The alues o esis ance, capaci ance and induc ance calcula ed by he ool a e shown in Table 27. Table 27. RLC alues Line Da a R [Ω/km] L [mH/km] C [μF/km] 0,0126 0,21 0,053 PIPE AND CONDUCTOR COST 14% CIVIL COST 2% GAS PRICE N2+SF6 23% TRANS. INSTAL. TESTING 38% ROUTING 0% PROJECT CONTINGENCY 12% PROJECT LAUNCH AND MANAGEMENT 11% 66 Table 28. Va iable cos s. Million € €/km €/MVA €/yea Powe losses 85,8 902,7 35.130,0 2.143.805,9 Cos educ.T ansm. Capac 5,6 58,7 2.285,0 139.444,4 Powe losses in he compensa ion uni 0,0 0,0 0,0 0,0 Ope a ion and main enance 29,4 310,0 12.063,2 736.158,8 To al a iable cos s 120,8 1.271,3 49.478,2 3.019.409,0 Figu e 33. Li e long cos dis ibu ion. In his dis ibu ion i can be con i med ha ansmission wha is epo ed in [11] ha powe losses a e he majo ac o o he ope a ion cos . They ep esen he 80% o he o al a iable cos s. 3. To al cos In Table 29 a e shown o al cos alues, and in Figu e 34 is shown he cos dis ibu ion. Powe losses 71% Cos educ.T ans. Capac 5% Compensa ion 0% Ope a ion and main enance 24% 67 Gas Insula ed Lines. Technical-economic analysis Table 29. To al cos Million € €/km €/MVA €/yea TOTAL COST 509,0 5.357,8 208.516,8 3.019.409,0 In Figu e 34 is shown he o al cos dis ibu ion. Figu e 34. To al cos dis ibu ion. 4.1.2 Sensi i i y s udy o GIL The analysis o sensi i i y shows he e ec ha di e en a iables ha e on he inal cos o he GIL in as uc u e. In he p e ious g aphic i can be seen ha each cos does no ha e he same impo ance. Pipe and conduc o cos and powe losses a e mo e signi ican han he o he s. No mally in a sensi i i y s udy o an ins alla ion he p o i abili y s udy is done o come up wi h impo an economic a iables as VAN and TIR o e en Pay-Back ime. Howe e in his p ojec , his pa ame e s a e no calcula ed as he inpu s o money ecei ed due o ope a ion and main enance o he line a e no a ailable o a pa o a bid g id. In case o GIL di e en a angemen s ha e been done, o see which a e he mos impo an sensibili ies ha can ha e signi ican impac on he inal p ice o he in as uc u e. PIPE AND CONDUCTOR COST 12% TRANS. INSTAL. TESTING 28% CIVIL COST 1% GAS PRICE N2+SF6 16% GIS+Compensa o 2% PROJECT CONTINGENCY 4% PROJECT LAUNCH AND MANAGEMENT 13% Powe losses 17% Cos educ.T ans. Capac 1% Ope a ion and main enance 6% 68 4.1.2.1 Type o laying (soil: so ock) Fi s o all, he ci il wo k cos does no seem impo an in his p ojec . In Table 30 i can be seen ha he ype o laying does ha e a li le e ec on he inal cos . This cos anges om 4,5 million o a di ec ly bu ied o 34,5 million o squa ed unnels. Table 30. Type o laying sensi i i y. Ci il wo ks cos Million € €/m €/MVA Di ec ly bu ied 5,6 59,0 2.296,2 T ench 27,9 293,7 11.429,9 Squa ed unnel 41,2 433,6 16.873,3 4.1.2.2 Type o soil o a di ec ly bu ied sys em Secondly he ype o soil is s udied (Table 31). The columns e e o he same meaning as he p e ious s udy. I can be seen ha independen ly o he ype o soil ci il wo ks a e s ill almos insigni ican o he o al cos e e ing o less o 2%. Table 31. Type o soil sensi i i y. Million € €/m €/MVA Disagg ega e 1,1 11,3 441,7 Loose 1,3 13,6 529,5 Compac 1,6 17,0 662,0 Ha d 2,8 29,5 1.147,6 So ock 5,6 59,0 2.296,2 Ha d ock 9,0 94,4 3.673,5 4.1.2.3 To al cos unc ion o me al p ice In his case s udy he p ice o me al is in e e ence o Table 25 4,2 €/kg o he ou e enclosu e pipes and 5,2 €/kg o he conduc o pipes. As can be seen in he p e ious cha s, he p ice o he pipes is one o he mos signi ican componen s o he GIL ins alla ion, he e o e, i is o huge in e es o know he e ec ha he aluminium p ice has on he o al cos . 69 Gas Insula ed Lines. Technical-economic analysis In Table 32 can be app ecia ed as o al cos o GIL in as uc u e does highly depend on p ice o me al. This shows he g ea impo ance ha ha e me al p ices o y o educe as much as possible ins alla ions p ice. Table 32. Sensi i i y s udy o he p ice o me al P ice o me al Cos o me al pa s (M€) TOTAL COST (M€) % 2€/kg 24,4 426,6 5,7 3€/kg 36,5 459,1 8,0 4€/kg 48,57 491,6 9,9 5€/kg 60,6 524,1 11,6 4.1.2.4 Gas mix u e The gas mix u e used nowadays does ha e high en i onmen al conce ns due o he p esence o SF6. Since many yea s al e na i e gases ha e been s udied o y o eplace SF6. Pe haps he insula ing gas CF3I can be he al e na i e in he nea u u e. Techniques o p oducing his gas a e being highly imp o ed, he e o e i s p ice is being cons an ly educed. Fu he mo e his new p oduc ion me hods may each necessa y equi emen s o ensu e massi e indus ial p oduc ion. In e e ence o [12] he p ice o CF3I has been educed o e 630 £/kg o 62,86 £/kg in 2014. The change a e used be ween £ and € is 1,1 € is 1£. The mass o gas equi ed o 1 km single phase GIL is 5,72 onnes, which makes 1.630 onnes o he s udied case, ha is o a h ee phase sys em 95 km long [12]. Wi h his in o ma ion is made he sensi i i y s udy o he al e na i e gas CF3I. In Table 33 a e shown alues o o al cos in e e ence o gas p ices. Table 33. Gas sensi i i y P ice 𝐂𝐂𝐒𝐒𝐂𝐂𝐂𝐂 [€/kg] To al cos (M€) Gas P ice (M€) % 69,15 (2014) 575,4 112,7 19,6 50 490,1 81,5 16,6 25 380,4 40,8 10,7 10 314,6 16,3 5,2 5 292,7 8,2 2,3 I can be seen ha o al p ice o he GIL in as uc u e a 2014 p ices is much mo e expensi e han when SF6 is used. This high p ice may make GIL no an app op ia e al e na i e o be used. In case p ices we e educed, p obably he CF3I gas would be he al e na i e. 70 4.2 O e head lines I is o high in e es o compa e o al cos o in es men and li e-long expenses be ween GIL ins alla ions and OHL. This in e es is mo i a ed because, no mally ansmission sys em ope a o s end o selec OHL ins alla ions ins ead o o he sys ems such as unde g ound lines o e en GIL, due o hei lowe cos . The OHL will be compa ed o he GIL op ion o he p esen ed case s udy. Fu he mo e in his case s udy i is especially impo an o see i he e a e any cheape echnologic solu ion o ace en i onmen al es ic ions[32]. To s udy he cos s o o e head and unde g ound lines, he cos s o ins alla ion ha e been ob ained om [37][38]. This documen p esen s cos s associa ed o he cons uc ion and main enance o ansmission lines, i.e. OHL and unde g ound cables, in Spain. Rega ding da a o he cons uc ion o he OHL sys em de ined by REE in [39] and [32] o he connec ion be ween Pinilla and Co en es, i is collec ed in Table 34. Table 34. P ojec cons uc ion pa ame e s. Sys em Al e na ing h ee phase cu en Vol age 400 kV Conduc o ’s maximum empe a u e 85 ºC Numbe o ci cui s 2 (1 ins alled) Numbe o conduc o s pe phase 3 Type o conduc o Condo AW O he impo an da a e e ed o his p ojec such as li elong ime, discoun a e, wo king hou s, e c, is he same as o he GIL ins alla ion. 4.2.1 Ini ial in es men cos s. Fixed cos s Acco ding o he in o ma ion gi en o he ini ial in es men cos s in [37], p ice o he s udied 400 kV line is 373.047 €/km. This cos e e s o cables, s uc u es, ci il wo ks, ins alla ion cos and e en launch, managemen and con ingency. No ice ha he selec ed ype o OHL p ojec is 400 kV ( iplex) simple ci cui which e e s o he ins alled ci cui . Apa om he dis ance dependen cos s, he cos o GIS ins alled a each end o he in as uc u e also ha e o be included. Acco ding o [34] each GIS o a 400 kV and 63 kA sys em is 2,5 M€. 71 Gas Insula ed Lines. Technical-economic analysis To al ini ial in es men cos s a e shown in Table 35: Table 35. To al ini ial cos . Million € €/m €/MVA €/yea Ini ial in es men Dis ance dependen cos s 35,4 373,0 14518,4 885986,6 Dis ance non-dependen cos s 5,0 52,9 2058,6 125628,3 To al ini ial ins alla ion cos 40,5 425,9 16577,1 1011614,9 4.2.2 Va iable cos s The a iable cos s o ins alla ion include he ope a ion, main enance, he cos o powe losses and he cos ela ed o a educ ion o powe capaci y o he line due o eac i e powe . 4.2.2.1 Ope a ion and main enance Cos s o main enance and ope a ion a e ob ained om he e e ence [37]. I can be seen ha he main enance cos pe yea o a 400 kV line is 3.106 €/km. In o de o calcula e he o al cos o he li e-long ime o he ins alla ion (40 yea s) he ollowing equa ion is used: M&O=(1+i)n−1 i(1+i)n ∗ Cos M&O (66) whe e; i: discoun a e; n: ins alla ion’s numbe o yea s o li e; In he s udied case M&O= 5,1 M€ o he li e ime pe iod. 4.2.2.2 Powe losses in cables and educ ion o ansmission ene gy due o eac i e powe The s udy o he cos s o hese pa ame e s seem impo an as hey may ha e a g ea e ec on o al inal cos o a high ol age line. In o de o come up wi h hese pa ame e s, powe losses and he capaci i e and induc i e powe in he line, i is necessa y o know he alues o esis ance (Ω) capaci ance (F) and induc ance (H). The OHL conduc o used in his p ojec has been indica ed a he p ojec done by he company REE, o his speci ic new elec ic in e connec ion [38]. The main p ope ies o he cable a e 72 indica ed in p oduc speci ica ions ables as [40]. No e ha he conduc o used is Condo /AW which is o med by aluminium wi es, concen ically s anded a ound a s eel co e wi e. In Table 36 signi ican da a has been collec ed [40]: Table 36. Conduc o 's da a. Mass 1116,2 kg/km Resis ance 0,069 Ω/km To al diame e 27,73 mm S eel diame e (co e) 9,24 mm Aluminium c oss sec ion a ea 402,6 mm2 To al cable sec ion 603,48 mm2 No e ha he esis ance pe km has been indica ed o a empe a u e o 25 ºC. F om [41], he ela ionship be ween esis ance and empe a u e is: R2= R1 [1 + α(T2−T1)] (59) whe e; Ri: esis ance a empe a u e (Ti [K]) [Ω]; α: empe a u e coe icien [1/K]. Fo aluminium he empe a u e coe icien is 4,46 ∗10−3 [1/K] [42]; i is only conside ed he coe icien o empe a u e o aluminium as he g ea pa o he conduc o ’s sec ion is made o aluminium. The wo king empe a u e depends highly on many pa ame e s, mos o hem uncon ollable; in o de o gi e an app oxima ion o he esis ance a no mal condi ions, he empe a u e conside ed is 85ºC [38]. Wi h his assump ion, he esis ance o each conduc o in OHL is: R2= R1 [1 + α(T2−T1)] = 0,069 [1 + 4,46 ∗10−3(85 −25)]=0,087 Ω/km (60) In ensi y pe cable o he e e ed line which has one ci cui and h ee conduc o s pe phase is: I = S 3∗√3∗400 =2441 3∗√3∗400 = 1,17 kA (61) To calcula e he induc ance and capaci ance pa ame e s o he s udied line, i is impo an o know hei dependence on he geome y o he owe s and he ma e ial o he conduc o . In his case he e is a beam o h ee conduc o s pe phase colloca ed a he e ex o a egula polygon, in his case an equila e al iangle. 73 Gas Insula ed Lines. Technical-economic analysis The geome y and dis ances be ween conduc o s o a beam and he dis ances be ween phases o he sys em a e shown in Figu e 35. Figu e 35. Dis ances o beams o conduc o s. (Da a sou ce: [37]) The ype o owe and dimensions ha e been ob ained om a simila p ojec done by REE. In Figu e 36 a e indica ed hei dimensions. No ice ha in he p ojec Pinilla – Co en es, al hough he owe used can sus ain wo ci cui s, o da e only one ci cui has been ins alled [38], ha means ha only one o he symme ic pa s is used. Figu e 36. OHL owe . (Da a sou ce: [39]) The induc ance pe km is calcula ed [41]: L = ln DMG RMG [mH/km] (62) 80 The esis ance, capaci ance and induc ance pa ame e s o he unde g ound cable ins alla ion esul o be: Table 42. RLC alues Line Da a R [Ω/km] L [mH/km] C [µF/km] 0,00832 0,35 0,23 Wi h alues ob ained ( a io Q/P<0.2), no compensa ion uni s a e needed; he e o e he e a e no losses e e ed o he compensa ion uni s; howe e he cos o powe capaci y educ ion due o eac i e powe has o be s udied. In Table 43 a e shown he a iable cos s o he Unde g ound Cable ins alla ion. I is ema kable o ou line he low p ices o powe losses; his low a es a e a consequence o he low esis ance alues ound o he cables used in his ins alla ion. Table 43. Va iable cos s Million € €/m €/MVA €/yea Powe losses 27,9 293,3 11.415,7 696.643,5 Cos educ .T ans. Capac 8,3 87,4 3.400,9 207.541,0 Losses in Compensa ion 0,0 0,0 0,0 0,0 To al a iable cos s 36,2 380,7 14.816,6 904.184,6 Table 44. To al cos Million € €/m €/MVA €/yea TOTAL COST 526,7 5.544,1 215.769,2 13.167.312,8 4.4 Case s udy esul s discussion F om he compa ison s udy o he Pinilla-Ayo a-Co en es elec ic line has been done a cos app oxima ion o h ee di e en elec ic echnologies. These cos app oxima ions a e o high in e es o na ional g id companies as bo h he di e ences be ween he cos componen s can be ou lined and o al cos s o lines can be p edic ed. P ices go o his ins alla ion compa ison can be ex apola ed o o he simila ins alla ions. 81 Gas Insula ed Lines. Technical-economic analysis In e e ence o he case s udy done, i can be seen ha as i was p edic ed GIL ins alla ions may ha e mo e expensi e cos a es han OHL; u he mo e, in his case he cos s associa ed o GIL and Unde g ound Cable ins alla ions, a e e y simila . This simila i y be ween p ices o bo h echnologies can be explained by he highe capaci y o GIL o low g ea e quan i ies o cu en [45]. No ice ha his compe i i eness in p ice be ween Unde g ound Cable ins alla ions and GIL depends much on he signi ican sensible cos pa ame e as i is he me al p ice; in Table 45 is gi en a sum up o all he main cos componen s o each s udied echnology o he case o he new ins alla ion Pinilla – Co en es. Di e en me al p ice scena ios can be seen o ealize when would be a GIL ins alla ion cheape han o he ypes o echnologies depending on his sensi i i y; also a e shown di e en p ice scena ios o he gas CF3I which may be he u u e o GIL ins alla ions. Table 45. Cos compa ison GIL OHL and Unde g ound cables. GIL Million € Ini ial in es men 388,2 Va iable cos s 120,8 To al cos 509,0 GIL sensi i i y P ice o me al To al cos 2 €/kg 426,6 3 €/kg 459,1 4 €/kg 491,6 5 €/kg 524,1 P ice o gas (CF3I) To al cos 5 €/kg 292,7 10 €/kg 314,6 25 €/kg 380,4 50 €/kg 490,1 69,15 €/kg (2014) 575,4 OHL Ini ial in es men 40,5 Va iable cos s 277,8 To al cos 318,2 Unde g ound Cables Ini ial in es men 490,5 Va iable cos s 36,2 To al cos 526,7 This p e ious able and he cos s udy done can p o ide some conclusions: 82 • The p ice sensi i i y shows how much is impo an he me al p ice and he gas p ice in o de o ensu e GIL o be an al e na i e o be implemen ed in HVAC ins alla ions, a leas in compa ison wi h unde g ound cable ins alla ions. • Rega ding a iable cos s, i is signi ican ha he e can be seen big di e ences in he powe losses cos and he cos due o educ ion o powe capaci y as a cause o he a ia ion o he esis ance, induc ance and capaci ance pa ame e s o he di e en echnologies. No e ha his di e ences in cos ange om 36,2 million € o an Unde g ound Cable ins alla ion o 277,8 million € o an O e head Line. No e he low a iable cos s o unde g ound ins alla ions, which a e a mainly a consequence o he low esis ance alues o he cable used. • The a iable cos s o OHL ins alla ions a e huge due o high powe losses, mainly a consequence o he high esis ance alue o he conduc o . This can be con as ed wi h low ini ial in es men , which is o lowes in e e ence o GIL and Unde g ound Cables. In he end i can be said ha GIL can become a compe i i e solu ion in compa ison o OHL and Unde g ound Cables in many cases i me al and gas p ices a e low enough ha ensu e GIL compe i i eness. 83 Gas Insula ed Lines. Technical-economic analysis 5. Conclusion Finally wi h he de eloped ool i is possible o ins i u ions and elec ic companies o do a cos s udy o he GIL echnology. O cou se, his ool is going o enease he GIL implemen a ion, as a cos s udy gi es he oppo uni y o compa e echnologies wi h economic pa ame e s. Fu he mo e, i can be s a ed ha GIL is no so a away om being a mo e used HVAC elec ic sys em; his is because on he one hand elec ic in e connec ions will need o ha e highe powe a es a compe i i e p ices, and his is an ad an age o GIL; on he o he hand he g ea isual and en i onmen al impac ha c ea e OHL is willing o be de ea ed; i can be done by using he unde g ound layou o GIL. Wi h his hesis and ool, he oppo uni y o design and see he cos o di e en ins alla ion a angemen s is possible, he e o e i may become simple he possibili y o s udying which a e hose op imum echnical solu ions ha come wi h he bes en i onmen al a angemen . In he end, his wo k has p o ided some cos unc ions ha we e p e iously no ound in he li e a u e. The e o e, he aim o his inal deg ee p ojec s is conside ed o be accomplished, ha ing p o ided a ool which gi es a cos app oxima ion o all echnical a angemen s o GIL ansmission sys em. On he o he hand, some u u e wo k is able o be done o expand he u ili y o he echnical- economic analysis o GIL: • Pe haps he mos in e es ing one would be o gi e a comple e ool ha would gi e a he same ime a cos app oxima ion o he main elec ic ansmission echnologies (OHL and Unde g ound Cables) wi h GIL. • Ano he poin ha can be imp o ed, echnical alues o GIL do no only depend on ol age and appa en powe , bu hey depend on many o he aspec s as wo king empe a u e; i would be o high in e es o come up wi h an imp o ed ool ha akes in o accoun o he pa ame e s no used o app oxima e cos . • The nex s ep o he designed ool is he possibili y o i o ge om he in e ne cu en and upda ed alues o he ma e ial p ices. 84 Re e ences [1] “Gas Insula ed T ansmission Lines.” [Online]. A ailable: h p://www.be aenginee ing.com/high- ol age-indus y-blog/gas-insula ed- ansmission-lines. [Accessed: 07-Jun-2018]. [2] “Paque e de medidas sob e clima y ene gía has a 2020 | Acción po el Clima.” [Online]. A ailable: h ps://ec.eu opa.eu/clima/policies/s a egies/2020_es. [Accessed: 07-Jun-2018]. [3] “Elec ici y in e connec ion a ge s - Eu opean Commission.” [Online]. A ailable: h ps://ec.eu opa.eu/ene gy/en/ opics/in as uc u e/p ojec s-common-in e es /elec ici y- in e connec ion- a ge s. [Accessed: 06-Jun-2018]. [4] H. Koch, “Gas-Insula ed T ansmission Lines (GIL),” Gas-Insula ed T ansm. Lines, 2011. [5] E. Ten and Y. S a emen , “Appendix E,” 2015. [6] “ o es eléc icas al a ensión - Busca con Google.” [Online]. A ailable: h ps://www.google.com/sea ch?q= o es+eléc icas+al a+ ensión&clien = i e ox-b- ab& bm=isch& bo=u&sou ce=uni &sa=X& ed=0ahUKEwjXoLm15dDbAhUI BQKHV8 BpwQsAQI OQ&biw=1366&bih=641#img c= KFaTKCD B zdM: [Accessed: 13-Jun-2018]. [7] M. Ra iq, D. Khan, M. Ra iq, S. F. Ra ique, I. Khan, and F. Abbas, “Compa ison o ansmission losses and ol age d ops o GIL ( Gas Insula ed ansmission line ) and o e head ans .... Compa ison o ansmission losses and ol age d ops o GIL ( Gas Insula ed ansmission line ) and o e head ansmission lines,” no. Ap il, pp. 4–7, 2017. [8] E. Ne wo k, “Technologies o T ansmission Sys em,” 2016. [9] “Gas-insula ed ansmission lines ( GIL ).” [10] “Cali o nia Limi s SF6, Wo ld’s Mos Po en G eenhouse Gas.” [Online]. A ailable: h p://www.ens-newswi e.com/ens/ma 2010/2010-03-02-091.h ml. [Accessed: 21-Feb-2018]. [11] H. Koch, Gas-Insula ed T ansmission Lines. . [12] K. Elnaddab, “E alua ion o Gas Insula ed Lines ( GIL ) o Long Dis ance HVAC Powe T ans e ,” no. Decembe , 2014. [13] D. M. I , Fa ac o s s o o In n e es m me en De ecis sion n L s . C Ca ble es o AC C T a T ans mis ssio on, no. Decembe . 2015. [14] “Cons uc ion o Fi s Gas Insula ed T ansmission Line in Japan,” p. 500, 1975. [15] U. N. E. A no , “ALUMINIUMS Gene al Tables Equi alences,” pp. 10–11. 85 Gas Insula ed Lines. Technical-economic analysis [16] C. Wes bo o, “Comp essed Gas Insula ed T ansmission Bus Sys ems,” no. 508, pp. 1–27. [17] I. B. Co al, “No Ti le,” 2018. [18] “5052 aluminium alloy - Wikipedia.” [Online]. A ailable: h ps://en.wikipedia.o g/wiki/5052_aluminium_alloy. [Accessed: 15-Ma -2018]. [19] C. Wes bo o, “Comp essed Gas Insula ed T ansmission Bus Sys ems P o en Solu ions.” [20] Aluminium Alloys - Aluminium 6063/6063A P ope ies, Fab ica ion and Applica ions. 2005. [21] “Banco de P ecios.” [Online]. A ailable: h p://www.cons uin o.com/FICHAP.ASP?CODIGO1=&CODIGO2=01TZ. [Accessed: 14-Ma - 2018]. [22] R. Bena o, C. Di Ma io, and H. Koch, “High capabili y applica ions o long gas-insula ed lines in s uc u es,” P oc. IEEE Powe Eng. Soc. T ansm. Dis ib. Con ., ol. 35131, pp. 605–612, 2006. [23] P. Shee , P.-E. Feb ua y, C. P ice, and S. Ph-, “p ice lis and condensed ca alog,” 2012. [24] J. Yli-hannuksela, “THE TRANSMISSION LINE COST,” 2011. [25] “P ecio en España de m2 de Fachada pesada de placa al eola de ho migón p e ensado. Gene ado de p ecios de la cons ucción. CYPE Ingenie os, S.A.” [Online]. A ailable: h p://www.gene ado dep ecios.in o/ob a_nue a/Fachadas/Pesadas/Paneles_p e ab icados_d e_ho migon/FPP030_Fachada_pesada_de_placa_al eola _de.h ml. [Accessed: 15-Ma -2018]. [26] “Issued 31s Janua y 2012 Wi h e a a Ap il 2012,” no. Janua y, 2012. [27] “P edicción del cos e de la ob a ci il de un únel ejecu ado po mé odos con encionales según Sub e a Ingenie ía - Ob as U banas.” [Online]. A ailable: h ps://www.ob asu banas.es/p ediccion-del-cos e-de-la-ob a-ci il-de-un- unel-ejecu ado-po - me odos-con encionales-segun-sub e a-ingenie ia/. [Accessed: 14-Ma -2018]. [28] L. Chen, P. Widge , M. S. Kama udin, H. G i i hs, and A. Haddad, “CF3I Gas Mix u es: B eakdown Cha ac e is ics and Po en ial o Elec ical Insula ion,” IEEE T ans. Powe Deli ., ol. 32, no. 2, pp. 1089–1097, 2017. [29] SF6 (Hexa luo u o de azu e). . [30] J. Rebled Lluch, “Powe ansmission sys ems o o sho e wind a ms: Technical-economic analysis,” pp. 1–121, 2015. [31] P. G. T. M. M. Gcb, “Gas Insula ed Swi chgea ( GIS ) Gene al P esen a ion Es ima ed To al Ma ke Size 2016,” 2016. [32] D. E. L. A. Línea and A. Eléc ica, “ESTUDIO DE IMPACTO AMBIENTAL DE LA LÍNEA ELÉCTRICA A 86 400 kV PINILLA-CAMPANARIO-AYORA-COFRENTES.,” 2008. [33] “China ubo del aluminio 5052, ubo edondo sacado, inconsú il pa a la ab icación del buque encendido Global Sou ces.” [Online]. A ailable: h p://spanish.globalsou ces.com/gsol/I/Aluminum-pipe/p/sm/1152696538.h m#1152696538. [Accessed: 14-Jun-2018]. [34] “China molino 6061 que acaba los ubos de aluminio del colo na u al con g ueso de pa ed ino y el OD en la p omoción encendido Global Sou ces.” [Online]. A ailable: h p://spanish.globalsou ces.com/gsol/I/Aluminum-pipe/p/sm/1142760038.h m#1142760038. [Accessed: 14-Jun-2018]. [35] “Pu chase SF6 Gas om Conco de Special y Gases | Conco de Special y Gases.” [Online]. A ailable: h p://www.conco degas.com/pu chase-s 6-gas/. [Accessed: 14-Jun-2018]. [36] “Lique ied Ni ogen Ln2 Gas Cylinde - Buy Lique ied Ni ogen Cylinde ,Ln2 Gas Cylinde ,Ni ogen Gas Cylinde s P oduc on Alibaba.com.” [Online]. A ailable: h ps://www.alibaba.com/p oduc -de ail/lique ied-ni ogen-LN2-gas- cylinde _60744083702.h ml?spm=a2700.7724857.no malLis .2.70916c21aAio9B&s=p. [Accessed: 14-Jun-2018]. [37] M. De Indus ia and E. Tu ismo, “O den IET / 2659 / 2015 , de 11 de diciemb e , po la que se ap ueban las ins alaciones ipo y los alo es uni a ios de e e encia de in e sión y de ope ación y man enimien o po elemen o de inmo ilizado que se emplea án en el cálculo de la e ibución de,” pp. 1–16, 2015. [38] M. D. E. Indus ia and E. Y. Tu ismo, “Bole ín o icial del es ado,” pp. 45805–45808, 2015. [39] “Plani icación de la ed de anspo e de elec icidad 2015-2020 - Comunidad,” 2015. [40] A. Aplicaciones, N. N c, A. B-, and A. B-, “ACSR / AW ACSR / AW CA al y p,” pp. 109–115. [41] A. Sumpe , “Sis emas El ´,” 2017. [42] R. M. Mujal Rosas, Cálculo de líneas y edes eléc icas. 2002. [43] X. Land and C. Sys ems, “XLPE Land Cable Sys ems Use ´ s Guide CONTENT.” [44] “HIGH VOLTAGE XLPE CABLE SYSTEMS Technical Use Guide.” [45] G. Schö ne , K. Oswald, S. Ag, and H. P d, “INVESTMENT REDUCTIONS.” 87 Gas Insula ed Lines. Technical-economic analysis