Overview of the energy storage systems for wind power integration enhancement

O e iew o he Ene gy S o age Sys ems o Wind Powe In eg a ion Enhancemen M. ĝZLHUF] ĔVNL Aalbo g Uni e si y [email p o ec ed] R. Teodo escu Aalbo g Uni e si y [email p o ec ed] C.N. Rasmussen Aalbo g Uni e si y [email p o ec ed] P. Rod iguez Aalbo g Uni e si y p o@ie .aau.dk H. Vikelgaa d Ves as Wind Sys ems he ik@ es as.com Abs ac -As he ins alled wo ldwide wind ene gy capaci y inc eases abou 30% annually and Kyo o p o ocol ha came in o ce in 2005, wind pene a ion le el in powe sys em is conside ed o signi ican ly inc ease in nea u u e. Due o inc eased pene a ion and na u e o he wind, especially i s in e mi ency, pa ly unp edic abili y and a iabili y, wind powe can pu he ope a ion o powe sys em in o isk. This can lead o p oblems wi h g id s abili y, eliabili y and he ene gy quali y. One o he possible solu ions can be an addi ion o ene gy s o age in o wind powe plan . This pape deals wi h s a e o he a o he Ene gy S o age (ES) echnologies and hei possibili y o accommoda ion o wind u bines. O e iew o ES echnologies is done in espec o i s sui abili y o Wind Powe Plan (WPP). Se ices ha ene gy s o age can o e bo h o WPP and powe sys em a e discussed. Mo eo e examples o al eady exis ing ins alla ions a e shown. Index Te ms-Wind Powe Plan (WPP), Ene gy S o age (ES), T ansmission Sys em Ope a o (TSO). I. INTRODUCTION N he pas decades he gene a ion o elec ici y was mos ly based on ossil uels and a omic ene gy. Howe e in ecen yea s he en i onmen al conce n and con inuously g owing p ice o ene gy om ossil uels was one o he easons o he apid g ow h o wind ene gy as a clean and inexhaus ible ene gy sou ce all a ound he wo ld [1], [2]. Acco ding o newes da a om Wo ld Wind Ene gy Associa ion (WWEA), e en in he yea 2009 which is he yea o global inancial c isis, he o al ins alled capaci y wo ldwide will each 152 000 MW by he end o 2009 [3]. This means ha in 2009 he e will be 30 300MW o new ins alled capaci y wha co esponds o 25% g ow h in compa ison o p e ious yea (Fig.1).Wha is mo e, acco ding o he epo o The Eu opean Wind Ene gy Associa ion (EWEA), yea 2008 in he EU was he i s yea in which mo e wind powe was ins alled han any o he elec ici y gene a ing echnology, (Fig.2) [4]. In 2008 in EU 8484MW o new wind capaci y was ins alled, bea ing all o he powe echnologies like coal, gas, and nuclea powe . As he ecen ly se ambi ious Eu opean plans o u u e sha es o enewables, he g ow h o wind powe can be expec ed o con inue [5]. Howe e u he wind ene gy in eg a ion o powe sys em encoun e s many new challenges. One o hem is he ac ha inhe en a iabili y and pa ly unp edic abili y o wind cause powe luc ua ions in he sys em ha can be e en mo e di icul o manage han load a ia ions including load- o ecas ing e o s [5]. Wind powe inc eases he need o he egula ion o powe and equi es ese es in he minu e o hou ime ames [6]. I inc eases he in eg a ion cos o wind powe because ese es a e o en p o ided by con en ional gene a ing uni s [7], [8]. Gene ally, he g ea e he wind powe pene a ion in o he powe sys em is, he bigge ese e powe is needed in o de o balance he g id du ing weak wind condi ions [9]. The U.S. Depa men o Ene gy es ima es ha , o e e y GW o wind capaci y added, 17 MWs o spinning ese es mus also be buil o accoun o he sys em’s a iabili y [10]. Wha is mo e, he bes wind esou ces a e o en ound in u al a eas a om exis ing high capaci y ansmission lines [11]. One o he ac ions ha can be aken o dec ease wind powe luc ua ions and a iabili y and allow u he inc ease o wind pene a ion in powe sys em can be an in eg a ion o ene gy s o age echnology wi h Wind Powe Plan (WPP). Fig. 2. Newly ins alled powe capaci y in EU, 2008 [4]. I Fig. 1. Global accumula i e ( ed) and global annual (g een) ins alled wind ca p aci y . ( 2009* p edic ed alue ) . 978-1-4244-6392-3/10/$26.00 ©2010 IEEE 3749 Ene gy s o age has al eady wide a ie y o applica ions like supplying powe o po able de ices, UPS and ecen ly in hyb id ca s o educe uel consump ion, e c. Howe e , addi ion o ene gy s o age echnology o WPP is no a good explo ed a ea ye . In mo e ecen imes, he complemen a i ies be ween s o age and enewables has become o pa icula in e es , bo h in e ms o cap u ing enhanced alue om such essen ially in e mi en esou ces and in main aining s abili y in he elec ical powe sys em [12]. This pape makes a e iew o ene gy s o age echnologies in espec o sui abili y o wind powe luc ua ion supp ession. In pa III po en ial applica ions o ES a e illus a ed and equi emen s o each applica ion a e s a ed. Pa IV assigns echnologies o applica ions and is ollowed by examples o ac ually exis ing ins alla ions o WPP wi h ES. II. OVERVIEW OF ENERGY STORAGE TECHNOLOGIES Ene gy s o age has he g ea es po en ial o sol e many wind in eg a ion issues [13]. Howe e , ES echnologies a e ha ing di e en po en ial and a e on he di e en s adium o de elopmen . Elec ical ene gy can be s o ed in o m o di e en kind o ene gies: mechanical, elec o-chemical, elec omagne ic, he mal. Fig. 3 p esen s a classi ica ion o ene gy echnologies. Sho desc ip ion o ene gy s o age echnologies and hei possibili y o accommoda ion o wind powe is u he p esen ed in his pape . A. Pumped Hyd o Ene gy S o age (PHES) I is he la ges and he mos ma u e echnology a ailable [14] wi h abou 300 sys ems ope a ing wo ldwide [15]. PHES consis s o wo ese oi s and body o wa e a a ela i ely high ele a ion ep esen s po en ial o s o ed ene gy [15]. The p inciple o ope a ion is simple and du ing ene gy p oduc ion i is simila o hyd oelec ic powe plan . Du ing he “cha ging” p ocess wa e om lowe ese oi is pumped up o he uppe one. In “discha ging” p ocess wa e om uppe ese oi is eleased and lows h ough hyd o u bines which a e connec ed o gene a o s, p oducing elec ical ene gy [16]. Fig. 3. Ene gy s o age echnologies classi ica ion In case o hyd o powe plan pumping is i ele an . In mos cases he hyd o acili y could be used as s o age wi hou any pumping because i has a supply o wa e om a i e . So simply educing he ou pu om he hyd o acili y is equi alen o “cha ging” he s o age wi h p ac ically 100% o e iciency. PHES is a good solu ion o wind a ms. Ideal applica ion o PHES seems o be load le eling [14]. Wind a m suppo possibili ies: One o he p oblems o building hese s a ions is he lack o sui able places and he impac in he na u e en i onmen [17]. Rela i ely new app oach which can gi e mo e deploymen lexibili y is Unde g ound Pumped Hyd oelec ic Ene gy S o age (UPHES). This gi es a lexibili y o UPHES loca ion wha in consequence his echnology can be placed in ideal loca ions o unc ion wi h wind a ms [14]. Howe e , he p oblem is e y high echnical imma u i y o UPHES. Hyd o powe plan s a e one o he bes s o age solu ions o supp essing luc ua ions caused by WPP. B. Comp essed Ai Ene gy S o age (CAES) CAES is also a qui e old echnology; howe e he numbe o ins alla ions in he wo ld is jus wo [18]. CAES sys ems a e comp essing ai ia elec ical comp esso s in unde g ound ca i ies (sal ca e n, abandon mines, ock s uc u es e c.) and s o e i in a high p essu e. When ene gy is needed comp essed ai is eleased h ough a u bine, bu he ope a ing uni s wo ldwide inco po a e combus ion p io o u bine expansion in o de o inc ease he o e all e iciency [16], [18]. High powe and ene gy capaci y make CAES a good s o age solu ion o wind a ms. CAES can be used o equen s a -ups and shu downs. Cu en esea ch in CAES is ocused on he de elopmen o sys ems wi h ab ica ed s o age anks. Such an app oach will emo e he geological dependency and comp essed ai will be s o ed in anks wi h a highe p essu e. Sys em a ing will be smalle (se e al MW) because o he ank cos . The possible lack o geological dependence migh make CAES an in e es ing solu ion o in eg a ion wi h wind a ms [19]. Wind a m suppo possibili ies: C. Flywheel Ene gy S o age (FES) Flywheels a e ene gy s o age de ices which a e s o ing ene gy in o m o kine ic ene gy ( o a ing mass). Flywheels a e made up o sha ha o a es on wo magne ic bea ings in o de o dec ease ic ion [14]. Whole s uc u e is placed in a acuum o educe windage losses. The p inciple o ope a ion is simple. Du ing ‘cha ging’ p ocess o o is accele a ed o a e y high speed by a mo o and ene gy is main ained in a sys em as kine ic ene gy [14]. In ‘discha ge’ p ocess lywheels a e eleasing ene gy and d i ing he machine which is wo king now as a gene a o . Flywheels a e no e y well sui ed o wind a m suppo . They a e able o supp ess as wind powe luc ua ions bu Wind a m suppo possibili ies: Ene gy S o age MECHANICAL ELECTRO MAGNETIC ELECTRO CHEMICAL THERMAL Pumped Hyd o Comp essed Ai Flywheels Supe capaci o SMES Hyd ogen Flow Ba e ies Ba e ies Vanadium Redox Zn-B Polysulphide B omine Lead Acid Ni-Cd Li-ion NaS Zeb a LONG TIME SCALE MEDIUM SHORT 3750 wi h a small ime scale. They can be conside ed as a suppo o wind u bines in combina ion wi h ba e y sys em a he han s and alone. Howe e ene gy densi y is low and mo eo e sel discha ge a io is high. Une co Powe Technologies has demons a ed he applica ion o kine ic ene gy s o age o he smoo hing o he ou pu o wind u bine sys ems [12]. Mos o cu en esea ch is ocused on high speed lywheels which a e able o o a e wi h a speed e en up o 100 000 pm. D. Supe capaci o Ene gy S o age (SES) In SES ene gy is s o ed in elec ic ield. P inciple o ope a ion is he same as in con en ional capaci o ; howe e supe capaci o s use pola ized liquid laye s be ween conduc ing ionic elec oly e and conduc ing elec ode o inc ease he capaci ance. Due o he ac ha capaci ance is dependen also on he su ace a ea o elec odes, highly po ous ma e ial is used in o de o inc ease he a ea [16]. Supe capaci o s can be a ed e en up o 5000F. SES a e ha ing simila esponse cha ac e is ics and small ene gy densi y like FES bu hey do no ha e mo ing pa s and a e ha ing small sel discha ge a io. They a e able o supp ess as wind powe luc ua ions bu wi h a small ime scale. They can be conside ed as a suppo o wind u bines in combina ion wi h a ba e y sys em a he han s and alone. Wind a m suppo possibili ies: E. Supe conduc ing Magne ic Ene gy S o age (SMES) SMES s o es ene gy in magne ic ield. SMES consis s o supe conduc i e coil, powe condi ioning sys em, e ige a o and acuum [14]. Magne ic ield is p oduced by DC cu en ci cula ing h ough a supe conduc ing coil [16]. In o de o ge id o he esis i e losses caused by cu en low, he coil is kep in supe conduc ing s a e. Cooling medium is liquid helium o ni ogen. SMES a e unlikely o be used o in eg a ing enewables [14]. Supe conduc i e coil is e y sensi i e o empe a u e changes; mo eo e SMES has small ene gy densi y and powe capaci y up o 2 MW. SMES is now usually u ilized in indus ial powe quali y ma ke . Wind a m suppo possibili ies: F. Lead Acid Ba e y Ene gy S o age (LAES) I is he mos ma u e ( esea ch o e 140 yea s) and he mos commonly used ba e y s o age echnology a p esen [16], [14]. The e can be dis inguished wo kinds o lead acid ba e ies: looded (FLA) and al e- egula ed (VRLA). FLA ba e ies a e cons uc ed om wo lead pla es which a e imme sed in a mix u e o sulphu ic acid and wa e . In case o VRLA ba e ies he ope a ional p inciple is he same; howe e hey a e sealed wi h a p essu e- egula ing al e which p e en s en ing o he hyd ogen and elimina es he ai om he cell. VRLA a e ha ing highe ini ial cos and sho e li e ime, howe e hey ha e an ad an age o e FLA in smalle weigh, olumes and lowe cos o main enance. LAES can be conside ed as a suppo o wind powe . The e exis s a iona y applica ion o LAES in he wo ld a ed in MW o powe sys em applica ions; howe e LAES usually lose wi h o he ba e ies when i comes o wind powe in eg a ion, mainly because o smalle powe densi y, low dep h o discha ge, li e cycle capabili y and ex eme sensi i i y o empe a u e changes. Also dep h cycles a e dec easing he li e ime o LA ba e ies. Wind a m suppo possibili ies: Cu en ly e o is pu in esea ch o LA ba e ies ha can be cha ged in minu es [14]. I is a he unlikely ha his echnology will be playing impo an ole in a u u e as a la ge scale s o age de ice, mainly due o e y limi ed numbe o cycles. Mo eo e , an in e es ing solu ion seems o be also ul a ba e y which is LAES wi h in eg a ed supe capaci o in one uni cell de eloped by CSIRO. Ul a ba e y can p o ide high powe discha ge and cha ge wi h a long, low-cos li e [25]. G. Nickel Cadmium Ba e y Ene gy S o age (NCES) Nickel Cadmium is a ma u e solu ion simila like a LA ba e ies [18]. NCES consis s o posi i e elec ode (nickel hyd oxide) and nega i e one (me allic cadmium). Elec odes a e sepa a ed by nylon di ide and aqueous po assium hyd oxide is he elec oly e. Du ing discha ging p ocess nickel oxyhyd oxide eac s wi h wa e and p oduces nickel hyd oxide and a hyd oxide ion. A he nega i e elec ode cadmium hyd oxide is p oduced. Du ing cha ging p ocess o he ba e y p ocess is e e sed. NiCd ba e ies can ope a e in wide empe a u e ange in compa ison o LA. I NiCd ba e ies a e ope a ed wi h small dep h o discha ge, hen hey a e able o achie e much mo e cycles. I is a he unlikely o use his echnology o WPP pu poses [14]. I exis a possibili y o o al ban o NiCd ba e ies by Eu opean Commission [16]. Li e span o NiCd ba e ies can be signi ican ly educed o a deep cycles. Wha is mo e his echnology su e s om memo y e ec . O he p oblem is he en i onmen al impac o he echnology. Cadmium is a oxic hea y me al and he e a e conce ns ela ed o disposal. Wind a m suppo possibili ies: H. Li hium Ion Ba e y Ene gy S o age (LIES) This echnology was i s comme cially a ailable in 1990 [16]. The ca hode is li hia ed me al oxide while anode is g aphic ca bon wi h laye s uc u e [26]. The elec oly e is a li hium sal in o ganic sol en . In his case du ing discha ging li hium mig a es om anode o ca hode. Du ing cha ging e e se p ocess occu s. The weigh o LIES is app oxima ely one hal compa ed o NCES o simila capaci y and olume is 40 o 50% smalle han NCES [27]. This echnology can be sized in MW and he e o e become a se ious playe in la ge scale applica ions. LIES seems o be ele an o WPP. Cha ac e is ic ea u e o his echnology is Wind a m suppo possibili ies: 3751 small weigh , high e iciency and high cell ol age and powe densi y. LIES can be shaped in o a wide a ie y o shapes and sizes. Mo eo e his echnology does no ha e a memo y e ec . O he ea u es a e small sel discha ge (0.1% pe mon h) and long li e o deep cycles. I is likely ha LIES pe o mance will be signi ican ly imp o ed because o a lo o esea ch is done especially in espec o elec ic ca s. I. Sodium Sulphu Ba e y Ene gy S o age (NaSES) Sodium Sulphu ba e ies became comme cially a ailable in 2000. The cell is usually cons uc ed in a all cylind ical con igu a ion. Posi i e elec ode con ains mol en sulphu and nega i e elec ode om mol en sodium [14]. Elec oly e in WKLVFDVHLVVROLGȕ-alumina. Thus, du ing discha ging o he ba e y, sodium ions pass h ough elec oly e and combines a posi i e elec ode wi h sulphu , c ea ing sodium polysul ide. In cha ge p ocess eac ion is e e sed. NaSES ba e y can be classi ied o g oup o high empe a u e ba e ies. Because sulphu has o be kep in liquid o m, cell has o ope a e in empe a u e ange 320- 340°C. I cooled down when no ully cha ged, he ba e ies will su e se ious damage. Due o his a diesel gense is o en implemen ed oge he wi h a NaSES ins alla ion, in case o powe ou age. This echnology can be sized in MW and he e o e i can become a se ious playe in la ge scale applica ions. NaSES seems o be ele an o WPP. The e a e cu en ly wo king applica ions o NaSES wi h WPP. Wind a m suppo possibili ies: Cha ac e is ic ea u e in NaSES is high ene gy densi y ( h ee imes highe in compa ison o LAES) [14]. Wha is mo e NaS ba e ies a e able o deli e powe in single con inues mode as well as la ge sho pulses. NaSES a e capable o su i e much mo e cycles in compa ison o LA ba e ies. Cos o NaS ba e ies now is ela i ely high, howe e i is conside ed o d op wi h a mass p oduc ion because hese ba e ies a e cons uc ed om inexpensi e, abundan and ecyclable ma e ials [14]. Cu en ly howe e he e is only one manu ac u e o NaSES ba e ies, NGK Insula o s in Japan. J. Sodium Nickel Chlo ide Ba e y Ene gy S o age (ZEBRA) Sodium Nickel Chlo ide ba e y, popula ly called ZEBRA a e belonging o he amily o high empe a u e ba e ies. Nega i e elec ode consis s o liquid sodium (like NaS) bu posi i e elec ode is nickel chlo iGH $OVR ȕ-alumina elec oly e is used bu in addi ion he e is a second liquid elec oly e (sodium chlo oalumina e) which is used o allow as anspo o sodium ions o m he solid nickel chlo ide elec ode o and om ce amic elec oly e [20]. The bes pe o mance o a cell is achie ed o he empe a u e ange 250-350 °C. ZEBRA ba e ies a e able o play a ole in he u u e in in eg a ion o enewables. Howe e , igh now ZEBRA ba e ies aim mainly in e-mobili y. This echnology is cha ac e ized by high ene gy densi y (5 imes highe han LA). They a e esis an o sho ci cui s. Wha is mo e in compa ison o NaS, Zeb a ba e ies a e able o su i e ce ain o e cha ge and discha ge and ha e a be e sa e y cha ac e is ics and a highe cell ol age [16]. Wind a m suppo possibili ies: K. Flow Ba e y Ene gy S o age (FBES) The e can be dis inguished ollowing h ee kinds o low ba e ies: Vanadium Redox (VR), Polysulphide B omide (PSB), Zinc B omine (ZnB ). Flow ba e ies p inciple o ope a ion di e s om con en ional ba e ies. Ene gy is s o ed as a po en ial chemical ene gy by means o e e sible eac ion be ween wo elec oly es. Ene gy is s o ed in he elec oly e solu ions. This makes he powe and ene gy capaci y decoupled. The size o he cell s ack de e mines he powe capaci y, while he olume o elec oly e de e mines ene gy capaci y [16]. Two cha ged elec oly es a e pumped o he cell s ack. In he cell s ack a chemical eac ion occu s [14]. Fo each echnology cha ge o discha ge a ion is 1:1 and ba e ies do no su e om dep h discha ge. Ope a ion o Polysulphide B omide (PSB) is simila o VR. Cha ac e is ic ea u e is e y as eac ion ime. PSB ba e ies can be used o equency esponse and ol age con ol. The disad an age is he ac ha small quan i ies o b omine, hyd ogen and sodium sulpha e a e p oduced wha imposes some main enance [14]. In case o Zinc B omine (ZB) echnology, ope a ion p inciple is di e en han in p e iously men ioned VR and PSB ba e ies, howe e i con ains he same componen s. Du ing p ocess o cha ging he elec oly es o zinc and b omine ions low o he cell s ack. The elec oly es a e sepa a ed by a mic opo ous memb ane. The di e ence is ha elec odes in a ZnB low ba e y ac as subs a es o he eac ion. As he eac ion occu s, zinc is elec opla ed on he nega i e elec ode and b omine is e ol ed a he posi i e elec ode (simila o con en ional ba e y ope a ion). This echnology can be sized in MW and he e o e i can become a se ious playe in la ge scale applica ions. FBES seems o be ele an o WPP. The e a e al eady exis ing applica ions o VR wi h WPP. Wind a m suppo possibili ies: L. Hyd ogen Ene gy S o age (HES) Hyd ogen ene gy s o age is one o he mos imma u e echnologies [14]. Hyd ogen elec ic ene gy s o age is no a single de ice bu he p ocess is di ided in o h ee pa s: xc ea e hyd ogen xs o e he hyd ogen xc ea e ene gy om hyd ogen Hyd ogen can be c ea ed by: ex ac ion o ossil uels, eac ing s eam wi h me hane and by elec olysis. P oducing hyd ogen om elec olysis is he mos economical solu ion among he o he s. P oduc ion om ossil uels is ou imes mo e expensi e han using he uel i sel [14]. And p oduc ion o hyd ogen om eac ion o s eam wi h me hane 3752 p oduces pollu ion. Du ing he p ocess o elec olysis, hyd ogen is p oduced om wa e and oxygen is dissipa ed in o a mosphe e. La es ad ances inc eased he e iciency o hyd ogen p oduc ion o 85%. S o ing o hyd ogen can be done by comp essing i , by lique ying i o by me al hyd ide [14].The mos o en use op ion is o comp ess hyd ogen (65- 75% e iciency). Hyd ogen can be also s o ed in lique ied o m by p essu ing and cooling i . Howe e keeping he hyd ogen liquid is ene gy demanding because o he e y low empe a u e ha has o be main ained. To c ea e ene gy om hyd ogen wo me hods a e used: In e nal Combus ion Engine (ICE) and Fuel Cell (FC). Round ip e iciency is be ween 30-50%. Fuel cell is ela i ely new echnology and do no ha e any mo ing pa s, no emissions, a e ligh and eliable. Hyd ogen has a highe ene gy densi y pe weigh bu lowe pe olume han a gasoline. These ea u es gi e a lo o po en ial in a u u e, also wi h enewable applica ions howe e echnology needs o be mo e ad anced. Wind a m suppo possibili ies: Compa ison o ES echnologies can be ound in Table 1. III. APPLICATIONS OF ENERGY STORAGE FOR WPP AND GRID SUPPORT Ope a ion o ES as a pa o WPP can no only educe powe luc ua ions bu also enable in oduc ion o WPP in o new ma ke s. WPP cha ac e is ics can be made e en mo e like con en ional powe plan s. The challenge o wind powe esou ces in eg a ion is no a signi ican issue as long as he pene a ion a es a e small, ypically <10%. As pene a ion inc eases and becomes >20%, o he load, he e is equi ed added egula ion and spinning ese e esou ces o assu e g id s abili y con ol. Wha is mo e, inc eased wind gene a ion migh educe he egula ion capabili y o he con ol a ea by displacing o he gene a ion uni s (usually he less economical ones). G id ope a o may manda e ha all he wind gene a o s ha e o mee ce ain s abili y equi emen s as a condi ion o g id access [21]. Ene gy s o age sys ems can be applied o he wind esou ce in o de o p o ide all o some po ion o he addi ional egula ion con ol and spinning ese es [21]. Se ices ha ene gy s o age can o e o g id and WPP can be classi ied as ollows: xImposed by g id codes xAncilla y se ices (no equi ed by TSOs) A. Applica ions imposed by g id codes The pu pose is o supp ess luc ua ions o he equency in G id equency suppo a g id which ha e a sou ce in imbalance be ween gene a ion and load [21]. In g ids wi h high wind pene a ion, sudden educ ion o wind powe can con ibu e o equency d op. I is possible o suppo g id equency wi hou ene gy s o age in ce ain ange by u ilizing d oop con ol and o o ine ia. Wi h ES, equency can be con olled wi hou any cu ailmen s o wind powe . The p edic abili y o he p oduc ion om a WPP depends on he quali y o he wea he o ecas and o he se ice o ecas [11]. Fo ecas accu acy is dependen on ime scale, si e and season. In some coun ies o ecas is equi ed, howe e he e a e a ely any penal ies i o ecas is inco ec . In o he ma ke s, like Spain, he e a e penal ies imposed on wind ene gy supplie s when gene a ion does no ma ch amoun o gene a ion bid o deli e y [21]. P oduc ion p edic abili y ( o ecas imp o emen ) The e is usually a need o o ecas wi h 15min esolu ion. P oduc ion p edic abili y can be imp o ed (in consequence penal ies dec eased) wi h ES which can compensa e o some ex end un o eseen changes in he wind [11]. This se ice equi es ha wind ene gy in excess o bid amoun s is s o ed and eleased when he amoun o wind powe is insu icien . Ine ia emula ion is men ioned in he new d a o Spanish g id code as a u u e equi emen o a WPP connec ed o he g id [22]. Typically alue o ine ial cons an o wind u bine is dependen o he mass and is in ange o 4-9s. Inc eased ine ia in a g id educes equency a iabili y and makes he g id less sensi i e o sudden load and/o gene a ion changes. Addi ion o ES can signi ican ly inc ease he appa en ine ia o WPP. Ine ia I is also a new u u e equi emen ha can be ound in [22]. I no dis u bance is p esen , ela i e angula posi ions o synch onous machines o o s emain cons an . Sudden o signi ican changes o powe lows in an in e connec ed ansmission sys em some machines can loss synch onism. This se ice equi e ha powe oscilla ions be mi iga ed by injec ing and/o abso bing eal powe a equencies o 0.5 o 1 Hz, and may be encoun e ed in sys ems wi h long ansmission lines [23]. Oscilla ion damping Main aining adequa e eac i e powe is c ucial o ol age s abili y. This se ice can be ob ained by ull scale con e e connec ed o he g id wi hou ene gy s o age; howe e addi ion o ES is imp o ing egula ion pe o mance. Vol age con ol suppo Du ing he dis u bance in he g id wind u bines has o keep unning o ce ain pe iod o he black g id. This suppo s g id e-es ablishmen . Again LVRT can be done wi hou ES bu i equi es addi ional de ices and/o cu ailmen s in powe p oduc ion in o de o keep ol age on he DC link capaci o in sa e ange. Addi ion o ES can suppo LVRT by cha ging ES du ing aul and p o ec he DC link capaci o agains o e ol age. LVRT 3753 TABLE I COMPARISON OF ES TECHNOLOGIES. B. Ancilla y Ene gy S o age applica ions dP/d limi a ion o wind powe ou pu is a se ice ha limi s he a e o change o WPP. This allows o egula e addi ional dP/d limi a ion gene a ion as enough o compensa e wind luc ua ions. In some si es (especially emo e) i can happened ha wind de elope s ins alled mo e wind powe han ansmission T ansmission enhancemen sa ing Technology Powe capaci y [MW] Ene gy Capaci y [MWh] E iciency [%] Li e ime Ins alla ions (examples) Manu ac u e s PHES 30-4000 500 - 8000 70 - 85 Up o 50 yea s -The e is o e 90 GW in mo e han 240 PHES acili ies in he wo ld. Gugle GmbH, Sulze , No h Am. Hyd o, Wa e Alchemy, Ha is CAES 50-300 500- 2500 64 - 75 Up o 40 yea s -Hun o plan , Ge many, 290 MW, 580MWh - McIn osh plan , USA, 100MW, 2600MWh Tu boexpande , Als om, D esse -Rand, Sulze FES Up o 1,6MW ( o a LSF) Up o hou ( o a HSF) 80 - 90 20 yea s -Usually u ilized o UPS -P opulsion applica ions like engines and oad ehicles Ac i e Powe , Beacon, Hi ec, Pille , Pen adyne, Teledyne, U enco SES Up o 1MW Up o se e al seconds 90 - 98 10 yea s -Powe quali y applica ions - Hyb id ca s Maxwell, NESS Capaci o , EPCOS, ESMA, NEC SMES Up o 2MW 0,5-5MWh 90 - 99 20 yea s -Se e al used o powe quali y con ol -In Wisconsin, a s ing o dis ibu ed SMES uni s was deployed o enhance s abili y o a ansmission loop. Accel, Ha c, Supe conduc i i y Inc, In e magne ics Gene al Co po a ion Flooded LAES 0,01-10MW Up o 40MWh 75 - 85 Up o 2000 cycles -CHINO, Cali o nia, 10MW, 40 MWh -PREPA Pue o Rico, 20MW, 14MWh Ene sys , GNB (Exide) Val e- Regula ed LAES -HELCO Hawaii, 10MW, 15MWh -VERNON Cali o nia, 3MW,4.5MWh C&D Technologies , Hawke Ene gy (Ene sys) NCES 0.01–40MW Up o se e al hou s 60 - 70 1000 – 3500 cycles -Golden Valley, Fai banks, Alaska 40 MW o 7 minu es Sa , Alcad NaSES Up o 200MW Up o1200 MWh 86 - 89 4500 cycles, up o 15 yea s -Rokkasho, Japan 34MW/245MWh -Hi achi Plan 8MW/58MWh NGK Insula o s ZEBRA -In ehicles up o se e al hund ed kW, -Can be up o se e al MW In ehicles up o se e al hund ed o kWh -Can be up o se e al MWh 90 Mo e han 3000 cycles, up o 10 yea s -ZEBRA ba e y plan has been buil in S abio, Swi ze land 40MWh -mainly in hyb id ehicles Be a R&D LIES Up o se e al MW Up o se e al MWh 90 - 95 Mo e han 20000 cycles - a ie y o po able elec onic de ices - he e a e es s in MW ange Valence Johnson Con ol, Lucky Golds a Chemical, Sa , Li-Tec Ba e y GmbH, A123 Sys ems, BYD FBES VR Up o se e al MW Up o se e al MWh 70 - 80 >10000 cycles, 7-15 yea s -Se e al ins alla ions alongside wi h wind u bines P uden Ene gy FBES PSB 75 >2000 cycles FBES ZB 75 - 80 >2000 cycles -Two p oduc s comme cially a ailable ZESS 50kWh, ZESS 500kWh, -A ew ins alla ions planned in nea u u e wi h WTs ZBB Ene gy 3754 TABLE II OVERVIEW OF ES POWER AND ENERGY REQUIREMENTS FOR GIVEN SERVICE. in as uc u e can ans e . Addi ion o ES can de e g id upg ades. Ene gy can be s o ed du ing pe iods o insu icien ansmission capaci y and discha ged when capaci y becomes a ailable [21]. The abili y o a powe sou ce o go om a shu down condi ion o an ope a ing condi ion wi hou assis ance om he elec ical g id and o hen ene gize he g id o help o he gene a ing uni s s a a e a blackou occu s [23]. Black s a Sepa a ion o he ene gy p oduc ion ins an s and he ins an s o ene gy selling. In many g id a eas he p ice a ia ion can be e y high om hou o hou [24]. In o de o inc ease e enues ES sys em can be ully u ilized, i.e., ha powe is pu chased om he g id when o -peak wind gene a ion is insu icien o comple ely cha ge he ene gy s o age media [21]. Ene gy a bi age ES is s o ing ene gy when consump ion is low and eleasing i when consump ion is high o la en he ypical “moun ain and alley” shape o he load cu e [24]. Peak sha ing The p oduc ion o a WTG a ies wi h he wind. This can be le eled by ES. P oduc ion le elling So S op amps down he wind powe plan ou pu mo e slowly han he u bine amp a e, gi ing o he ene gy sou ces ime o s a up. This can e.g. be done, by he means o an ES [24]. So s op Powe sou ces online, synch onized o he g id ha can inc ease ou pu immedia ely in esponse o a majo gene a o o ansmission ou age and can each ull ou pu wi hin 10 minu es [23]. P ima y ese e Same as p ima y ese e, bu need no espond immedia ely; he e o e uni s can be o line bu s ill mus be capable o eaching ull ou pu wi hin he equi ed 10 minu es [23]. Seconda y ese e Same as seconda y ese e, bu wi h a 30-minu e esponse ime, used o es o e p ima y and seconda y ese es o hei p e-con ingency s a us [23]. Te ia y ese e Because o he ac ha ene gy s o age is expensi e solu ion i is unlikely ha single indi idual se ice may become economically iable. Thus, he e o should be pu o combine as many applica ions as possible; howe e some ES applica ions canno be combined wi h o he s because o di e en s a egy o ES managemen . P esen ed s o age applica ions can be g ouped depending on powe and ene gy equi emen s o ES as i is shown in Table 2. I can be seen ha mos se ices can be me wi h s o age able o ope a e wi h Ps ~ 50% o nominal plan powe and in ime scale o 1 hou [11]. IV. ENERGY STORAGE TECHNOLOGIES VERSUS APPLICATIONS The e a e many ypes o ES echnologies desc ibed in II bu none o hem is able o sol e all p oblems o wind powe in eg a ion in powe sys em. Pa icula ES selec ion is applica ion and imescale dependen and o WPP should be conside ed in ela ion o se ices ha a e demanded. Table 3 p esen s ES echnologies and applica ions ha hey a e able o gi e. I can be seen ha om he compa ison o s o age echnologies in espec o applica ions, he bes choices o WPP in eg a ion seems o be: PHES, CAES, LIES, FBES, NaSES and LAES. Howe e PHES and CAES echnologies placemen a e dependen o geological issues. Hyd ogen seems o ha e a huge po en ial in a u u e, howe e p esen s a e o de elopmen o his me hod makes i less e icien and e y expensi e solu ion o WPP. Supe capaci o s wi h combina ion wi h ba e y can be a good solu ion because o hei e y high cycling possibili y. I looks like as LAES a e less ele an o WPP in eg a ion han LIES, NaSES and FBES mainly because o smalle ene gy densi y, smalle dep h o discha ge and big sensi i i y o empe a u e changes. V. EXAMPLES OF ALREADY EXISTING APPLICATIONS OF ENERGY STORAGE FOR WIND POWER PLANT Combined s o age and wind u bines ins alla ions ha e a sho his o y, hus he e is only a ew examples o he ES applica ions. The eason o ha is he ac ha ES echnologies a e ela i ely expensi e solu ions (a leas a p esen ). Ano he aspec is ha un il now, he elec ic u ili y g id has se ed as a la ge-scale ene gy balancing and edis ibu ion sys em o in e mi en wind ene gy and i p o ided some le el o damping o luc ua ing wind powe . I is conside ed ha a numbe o coexis ing WPP and ES will ~25% o P ~30 -75% o P nom ~ 100% o P nom msĺPLQ nom Black S a , LVRT, Vol age con ol, Oscilla ion damping F equency con ol, Reg. Rese es, So s op, Peak Sha ing, Black S a , Oscilla ion damping, Ine ia F equency con ol, Reg. Rese es, So s op, Ine ia 1min – 60min Black S a , T ansmission enhancemen sa ing, Fo ecas imp o emen Reg. Rese es, So s op, Peak Sha ing So s op, Reg. Rese es, Peak Sha ing 1-10h Fo ecas imp o emen Ene gy a bi age Peak Sha ing, Ene gy a bi age, P oduc ion le elling Reg. Rese es, P oduc ion le elling 10hĺFo ecas imp o emen P oduc ion le elling P oduc ion le elling 3755 TABLE III COMBINATION OF ES TECHNOLOGIES WITH THEIR APPLICATIONS. inc ease in nea u u e as he pene a ion o wind gene a ion g ows [13]. TABLE IV COMBINED WIND POWER AND ENERGY STORAGE INSTALLATIONS Place Applica ion Speci ica ion ES Yea Rokkasho, Japan Fo ecas imp o emen , S eng hening weak g id, Peak sha ing shi ing, Powe egula ion, p ima y ese e 34MW/245MW h o 51MW wind a m NaS ES 2008 Tomamae Wind a m, Hokkaido Wind u bine s abilisa ion 4MW/6MWh o 30.6 MW wind pa k VR 2005 I eland, So ne Hill Wind Fa m Peak sha ing, powe quali y and eliabili y imp o emen 1.5MW/12MWh o 38MW wind a m VR 2006 Aus alia, King Island Local esiden ial g id s eng hening, equency and ol age con ol 200kW/800kWh o i e wind u bines anged 259-850kW VR 2003 Wind powe , Hokkaido S abiliza ion wind u bine ou pu 170 kW/1MWh o 270kW wind u bine VR 2001 The lis o he combined WPP and s o age ins allmen s is p esen ed in Table 4. VI. CONCLUSIONS Elec ical ene gy s o age is one o he mos p omising solu ions o he challenges ela ed o wind in eg a ion. S o age solu ions equi e signi ican in es men s and a e in oducing ene gy losses o WPP. These ea u es ha e o be weighed agains he bene i s ha s o age can p o ide. The e a e a numbe o di e en ES echnologies a ailable on he ma ke wi h di e en po en ial, cha ac e is ics and di e en applica ions ha can p o ide o WPPs. Some o he echnologies like NaSES and FBES a e al eady ha ing exis ing applica ions wi h WPP. I is also expec ed ha LIES will play a ole in he u u e in he WPP in eg a ion. The main ba ie s o widesp ead comme cial implemen a ions o ES wi h WPPs a e high cos o ES echnologies, imma u i y o some echnologies and unce ain y o e he quan i ied bene i s. Mo eo e , he u u e shape o he elec ici y ma ke will a ec decisi ely he iabili y o elec ical ene gy s o age. Fu u e scena ios in de egula ed ma ke like ancilla y se ices ading and s o age as a paid se ice o e ed o he g id can be decisi e [18]. Go e nmen subsidies o ES would also speed up widesp ead use o he new ES ins alla ions wi h WPPs. ACKNOWLEDGMENT This wo k is a pa o he esea ch being ca ied ou o he Ves as Powe p og am. The p og am is unded by Ves as Wind Sys ems A/S, Denma k and Aalbo g Uni e si y, Denma k. The au ho s g a e ully acknowledge he inancial and echnical suppo o Ves as Wind Sys ems A/S. REFERENCES [1] Chong Han, Alex Q. Huang, Wayne Li zenbe ge , Lo en Ande son, Abdel-A y Ed is "STATCOM Impac S udy on he In eg a ion o a La ge Wind Fa m in o a Weak Loop Powe Sys em", (1266-1272), 2006. [2] Ka suhisa Yoshimo o, Toshiya. Nanaha a, Gen a o Koshimizu, Yoshihsa Uchida "New Con ol Me hod o Regula ing S a e-o -Cha ge o a Ba e y in Hyb id Wind Powe /Ba e y Ene gy S o age Sys em", (1244-1251), 2006. [3] h p://www.wwindea.o g [4] EWEA annual epo , "Winning wi h Eu opean Wind C ea ing powe , helping he en i onmen ", 2008. [5] B.C. Ummels, E. Pelg um, W.L. Kling "In eg a ion o la ge-scale wind powe and use o ene gy s o age in he Ne he lands’ elec ici y supply", 2007. [6] Dany G. "Powe ese e in in e connec ed sys ems wi h high wind powe p oduc ion", 2001. [7] H. Hol inen e al. "Design and Ope a ion o Powe Sys ems wi h La ge Amoun s o Wind Powe , i s esul s o IEA collabo a ion", 2007. [8] Ma y Black, Go an S bac "Value o s o age in p o iding balancing se ices o elec ici y gene a ion sys ems wi h high wind pene a ion", 2005. [9] WWEA, "Wo ld wind ene gy epo 2008", Sou h Ko ea, 2009. [10] h p://www.pike esea ch.com/ esea ch/ene gy-s o age- echnology- ma ke s [11] Magnus Ko pås "Dis ibu ed Ene gy Sys ems wi h Wind Powe and Ene gy S o age", 2004. [12]Go don, S., P. Falcone, Sandia, "The Eme ging Roles o Ene gy S o age in a Compe i i e Powe Ma ke : Summa y o a DOE Wo kshop", 1995. [13] EPRI Technical Repo , "Wind Powe In eg a ion Technology Assessmen and Case S udies", 2004. [14] Ollscoil Luimnigh, Da id Connolly, Uni e si y o Lime ick "An in es iga ion in o he ene gy s o age echnologies a ailable, o he in eg a ion o al e na i e gene a ion echniques", 2009. 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[22] G id code d a , "Technical equi emen s o wind powe and pho o ol aic ins alla ions and any gene a ing acili ies whose echnology does no consis on a synch onous gene a o di ec ly connec ed o he g id", Oc obe 2008. [23] EPRI-DOE "Handbook o Ene gy S o age o T ansmission and Dis ibu ion Applica ions", 2003. [24] C.N. Rasmussen, AAU "Ene gy s o age echnology o e iew", 2009. [25] h p://www.csi o.au/science/Ul a-Ba e y.h ml [26] h p://www.elec ici ys o age.o g/si e/ echnologies/li-ion_ba e ies/ [27] h p://www.bydi .com/doce/p oduc s/li.asp Technology Se ice Sodium sulphu Flow ba e y Li hium Ion Supe capaci o Lead Acid Pumped-Hyd o CAES SMES Flywheel ES Ni-Cd Zeb a Fo ecas imp o emen Ine ia Oscilla ion damping G id equency suppo Vol age con ol suppo LVRT T ansmission enh. sa ing Black s a S o age a bi age Peak sha ing P oduc ion le elling So s op P ima y ese e Seconda y ese e Te ia y ese e 3756