windblatt 04/2007 world's most powerful wind turbine installed near

WINDBLATTENERCON Magaz ine fo r wind energyI ssue 04 | 2007

www.enercon.de

E-126 PROTOTYPE World’s most powerful windturbine installed near Emden

Page 6

PRACTICE138 metres tower: High performance turbines towering above treetopsPage 8

TECHNOLOGY3 x E-33 Wind Diesel

System: Wind reduces fuel

consumption on Falklands

0

SUPPLIERSKF at Schweinfurt/Bavaria:

Bearings for millions of

rotations

Page 14

INTERNATIONALMiyako Island/Japan:

Rebuilding of a wind farm

destroyed by a typhoon

Page 15

Editorial

ENERCON NewsShort news from the ENERCON World

Title StoryE-126 Prototype: World’s mostpowerful wind turbine installed nearEmden

Practice138 metres tower: High performanceturbines towering above treetops

Technology3 x E-33 Wind Diesel System: Windreduces fuel consumption on Falklands

InternationalNew wind farms in Italy: First towersmade in Bari

SupplierSKF at Schweinfurt/Bavaria: Bearingsfor millions of rotations

InternationalMiyako Island/Japan: Rebuilding of awind farm destroyed by a typhoon

Åland: ENERCON wind turbinesonshore offshore

Events and AddressesENERCON AddressesInfo-Service

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IINNTTEERRNNAATTIIOONNAALL SSAALLEESS OOFFFFIICCEESS

EENNEERRCCOONN GGmmbbHH,, IInntteerrnnaattiioonnaall DDeepptt..

Otto-Lilienthal-Str. 25 · 28199 Bremen · GERMANYPhone +49 421 2441 520 · Fax +49 421 2441539

e-mail: [email protected]

AAUUSSTTRRIIAA

ENERCON Austria Ges.mbH · Hauptstrasse 19 2120 Wolkersdorf · AUSTRIA · Phone +43 2245 82828

Fax +43 2245 82838 · e-mail: [email protected]

BBEENNEELLUUXX

ENERCON Benelux BV · Paxtonstraat 1 a 8013 RP Zwolle · THE NETHERLANDS

Phone +31 38 4228 282 · Fax +31 38 4228 010e-mail: [email protected]

BBRRAAZZIILL

Wobben Windpower Ltda.Av. Fernando Stecca nº 100 · Distrito Industrial CEP

18087450 Sorocaba · São Paulo · BRAZILPhone +55 15 2101 1700 · Fax +55 15 2101 1701


CCAANNAADDAA

Michael Weidemann · ENERCON GmbH International Sales Department

Oesterweg 9 · 59469 Ense · GERMANYPhone +49 2938 9720 17 · Fax +49 2938 9720 49


DDEENNMMAARRKK

ENERCON DenmarkBredkær Parkvej 62 · 8250 Egaa · DENMARK


FFRRAANNCCEE

ENERCON GmbH bureau français1, rue des Longues Raies · ZAC des Longues Raies

F-60610 La Croix Saint Ouen · FRANCEPhone +33 3 44 83 67 20 · Fax + 33 3 44 83 67 29

GGRREEEECCEE

ENERCON Hellas S.A.20, Pentelis Avenue · 15235 Vrilissia, Athens · GREECE


IINNDDIIAA

ENERCON India Ltd.Kolsite House, Plot No. 31 · Shah Industrial Estate

Veera Desai Road, Andheri (West)Mumbai 400 053 · INDIA

Phone +91 22 569 248 48 · Fax +91 22 267 300 85e-mail: [email protected]

IITTAALLYY

ENERCON ItaliaVia Luciano Manara, 5

00044 Frascati (Roma) · ITALYPhone + 39 06 94 01 69 1 · Fax + 39 06 94 01 69 299


NNEEWW ZZEEAALLAANNDD

ENERCON GmbHAndrea von Lindeiner · PO Box 340206

Birkenhead · Auckland 0746 · NEW ZEALANDPhone +64 (0)9 4199 231 · GER +49 4941 976 959-147


PPOORRTTUUGGAALL

ENERCON Portugalc/o Gellweiler S.A. · Rua Vitor Cordon, 37-4° Dt°

1200-481 Lisboa · PORTUGALPhone +351 21 340 71 65 · Fax +351 21 340 71 69


SSPPAAIINN

ENERCON Spain S.A.València Parc Tecnològic, Av. Juan de la Cierva, 27

46980 Paterna (València) · SPAINPhone +34 961 366 461 · Fax +34 961 366 469


SSWWEEDDEENN

ENERCON Energy Converter ABStenåldersgatan 19

21376 Malmö · SWEDENPhone +46 40 143 580 · Fax +46 40 222 420


TTUURRKKEEYY

ENERCON Servis Ltd. Sti.Bagdat Cad. No 187 A Blok daire 5

Selamicesme KadikoyIstanbul · TURKEY


ENER

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IMPRINTPublisher: ENERCON GmbH · Dreekamp 5 · 26605 Aurich · Germany

Phone +49 4941 927-0 · Fax +49 4941 927-109 · www.enercon.de/en/_home.htm

Editorial office: Volker Uphoff, Ruth Brand

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Copyright: All photos, illustrations, texts, images, graphic representations, insofar as this is not expressly stated to the

contrary, are the property of ENERCON GmbH and may not be reproduced, changed, transmitted or used otherwise without

the prior written consent of ENERCON GmbH.

Frequency: The WINDBLATT appears every three months and is regularly included in the

New Energy, magazine for renewable energies, of the Federal Association for Wind Energy, Germany.

Subscribe: Phone +49 4941 976-283 or www.enercon.de/en/_home.htm; stamp duty 2,- € per issue.

Cover photo: Installation of E-126 at Rysumer Nacken, Emden.

E D I T O R I A L WINDBLATT 04 | 2007 3

Dear Readers,This summer the German government finally adopted a comprehensive package of climateprotection measures. The key measure in the electricity sector is a review of the RenewableEnergy Act (EEG). The Federal government's field report on the Renewable Energy Act submit-ted on 5 July provided a good basis for discussions. The report suggested taking the degres-sion rate for wind energy down from 2 to an annual one percent. Although this is a step in theright direction, it is still not enough to bear the increase in costs for raw materials such as copper, steel, electroplates, nickel and chemical products such as paints and resins needed forwind turbine production. Since the last Renewable Energy Act amendment in 2004, steel prices on the international commodities market have risen by 50 percent and in the same pe-riod the price of copper has tripled. At least a portion of these costs has to be passed on to ourcustomers. The wind industry is in desperate need of a temporary suspension of the degres-sion to prevent the development of wind energy in Germany from being paralysed.

A second topic being considered is the introduction of a technology bonus: This would be ex-tremely wise as it would reward wind turbine owners who choose sophisticated systems fortheir wind farms. Such an arrangement would not only guarantee Germany a long term secu-rity of energy supply, but would also be a further incentive to promote more efficient and fle-xible renewable power supply systems. An appropriate bonus would support efforts made byinnovative companies, who – like ENERCON – actively contribute to further technological de-velopments in the wind energy sector. One of the more recent examples is the new FACTS (Fle-xible AC Transmission System) feature of ENERCON wind farm power electronics: This featureprovides for immediate reactive power supply without the intervention of additional sources(capacitors, inductors), as well as the capacity to ride through grid failures. ENERCON windfarms are thus able to contribute to power supply security even in weak grid sectors.

Another growing factor contributing to the expansion of wind energy is the development of fo-rest areas. Many of the best wind sites in the southern part of Germany are often situated inforest areas along the ridges of low mountain ranges. An advantage of these sites is that theyare off the beaten track – often so far away from the nearest housing construction that onlyhikers notice the wind turbines. At the same time, wind energy is opening up more financialopportunities for forest owners: In January this year, vast forest areas in Germany were deva-stated by hurricane Kyrill. Revenue from wind energy could provide the necessary funds to de-vise new concepts for restoring and managing forested landscapes.

Aloys WobbenManaging Director ENERCON GmbH

Yours sincerely

average wind speeds range between 10 to

11 m/s at hub height. Designed for IEC Wind

Class I, the E-70 turbines will be installed on

64 metre steel towers and the forecasted yield

of the two farms put together is expected to

surpass 250,000 MWh p.a.

Because the Strait of Gibraltar is a crucial stop

over for migrating birds, comprehensive re-

ports on how changes in the farm could affect

bird life had to be carried out before permissi-

on was granted. Several independent surveys,

however, convinced the regional nature con-

servation agency that the new farms with fe-

wer but taller and more powerful turbines

would have far less impact on bird migration

than their predecessors. Newer wind turbines

rotate at a considerably slower speed and are

much quieter than the old models. Bird life

should scarcely be affected.

“We’ll be building in three stages starting in

spring 2008”, reports ENERCON project ma-

nager, Christian Oberbeck. “First of all Pesur I

will be installed in two stages and then the

EEE wind farm will be completed.” Construc-

tion is scheduled to be finished by summer

2009. Contractor is the Sociedad Eólica de An-

dalucía in Tarifa, a subsidiary of Endesa.

This is the first ever repowering project in

Spain. Potential for repowering in Andalusia,

Galicia and on the Canary Islands is consider-

able as there is still large number of older

wind turbines dating back to the 250-kW ge-

neration. Spanish power feed laws now stipu-

late that wind farms erected before 2001need

to be updated. For every MWh of electricity

produced from repowered wind turbines, ow-

ners will receive an extra premium of 7 euros.

Costa Rica: First ENERCON wind farmin Central America

Between 2008 and 2009 ENERCON will be in-

stalling a total of 55 WECs in Costa Rica. The-

se E-44/900 kW wind turbines will be the first

ENERCON wind energy converters installed in

Central America. An agreement with the pro-

ject planers was signed in August. Included in

the group are the farm developers, juwi GmbH

(Mainz, Germany), Saret in Costa Rica – one of

4 WINDBLATT 04 | 2007 N E W S

This site will also house the administration for

ENEOP 3 and the Service department.

On the day of the inauguration, Prime Minister

Sócrates, Minister Pinho, and the mayor of Vi-

ana do Castelo, Defensor Moura, together with

ENERCON Managing Director Aloys Wobben

and Mechanic Anlagenbau GmbH Managing

Director Klaus Peters, first visited the Lanhe-

ses site to see the progress of construction

there and to lay a cornerstone. In the plant ne-

ar the harbour of Viana do Castelo, 250 guests

including local and national politicians, sup-

plier representatives, and members of the

consortium attended the official inauguration

of the rotor blade production facility and wit-

nessed the laying of the cornerstone for tower

production. On a walk through the rotor blade

facility, Aloys Wobben explained the manufac-

turing process to the Prime Minister.

There are currently 108 staff employed in ro-

tor blade manufacturing. This figure is expec-

ted to rise to 450 by the end of March 2008.

Andalusia: ENECON repowering olderwind farms near Tarifa

Work to tear down 250 of the 100-150 kW ca-

tegory turbines in the Planta Eólica del Sur

(Pesur I) and Energía Eólica del Estrecho (EEE)

wind farms near Tarifa is in progress since the

end of November. These outdated, 15-year old

AWP 56-100, MADE AE-20 and 23 Ecotecnica

20/150 turbines are being replaced by 37 mo-

re powerful E-70 plants during the next two

years. Rated power will thus rise from the cur-

rent 30.6 MW to a total of 74 MW.

Sites near the Strait of Gibraltar in Andalusia

are some of the windiest in Europe. Here,

First ENERCON production facility inaugurated in Viana do Castelo

“This is an important day for our country; a

decisive moment”, said Portuguese Prime Mi-

nister José Sócrates at the inauguration on

November 16th of the ENERCON rotor blade

production plant, the first of five ENERCON

manufacturing facilities in Viana do Castelo, a

port city in Northern Portugal. “From today on,

Portugal has an industrial core with the capa-

city to produce and export state-of-the-art

wind energy technology”, said Sócrates.

Minister for the Economy Manuel Pinho em-

phasised the harmonious and trustful relati-

onship between the Government, local autho-

rities, ENERCON, and the other consortium

members Energias de Portugal (EDP) as well

as the companies Generg, Finerge and Térmi-

ca Potuguesa. Without it, the first development

stage of this industrial complex could not ha-

ve been realised so quickly. “Our country can

be proud of this project”, said Pinho.

In 2006, ENERCON won the bid in a Portugue-

se Government tender for the installation of

1200 MW of wind energy primarily in the north

of the country. As a precondition for winning

the contract, the company had to set up in-

country manufacturing facilities.

The Portuguese subsidiary ENEOP 3

(“ENERCON Eolicas de Portugal”) comprises

two sites: Near the harbour of Viana, a

100,000 sqm area houses tower and rotor

blade production. 17 km away in Lanhesis, the

ENEOP 3 mechatronics building is being erec-

ted that will accommodate generator and

E-module production and nacelle assembly.

Portuguese Prime Minister José Sócrates (centre)with ENERCON managing directors Aloys Wobben(l.) and Klaus Peters.

View on Pesur I (Tarifa) and Strait of Gibraltar

Pict

ure:

Paul

o Du

arte

/Jor

nal d

e Ne

góci

os

Pict

ure:

Scan

u M

artin

,Sev

illa

Central America’s largest construction firms,

as well as Econergy.

Owner/operators of this project will be Proy-

ecto Eólico Guanacaste S.A. whose main sha-

reholder is the renewable independent power

producer, Econergy International PLC (Boulder,

Colorado). With a rated power of just under

50 MW and average winds speeds of approx.

12 m/s at hub height, yield is expected to

reach 240 GWh p.a. Compared to a coal power

plant “La Gloria” will be able to cut annual CO2

emissions by 240,000 tons.

The turbines are sited in the Northwest of

Costa Rica near the city of Liberia at an altitu-

de of 600 to 700 metres. ENERCON and the

owners also concluded an 11 year EPK agree-

ment. Costa Rica will have its own special

maintenance and service company. “We’re

certain that there will soon be more wind

farms to take care of”, says ENERCON’s sales

director Stefan Lütkemeyer.

ENERCON a competent and reliable partner for suppliers

ENERCON plans to continue its growth over

the coming years. Successful partnerships

with suppliers are a crucial prerequisite for

achieving this goal. “The satisfaction of both

business partners is the foundation of any

successful business relationship”, says

ENERCON Managing Director Hans-Dieter

Kettwig. That is why it was so important for

ENERCON to find out how its suppliers were

viewing the business relationship.

An online survey conducted earlier this year

showed that both domestic and foreign sup-

pliers were very satisfied with the relationship

with ENERCON, giving it an overall rating of 1.6

on a scale from 1 (“very satisfied”) to 6 (“dis-

satisfied”). The openness of communication

with ENERCON staff and the exchange of infor-

mation on a partnership relationship basis re-

ceived particularly good ratings (1.6 and 1.5,

respectively).

ENERCON is viewed as a reliable partner:

ENERCON’s reliability and follow-through re-

ceived a 1.6 rating. E-mail and telephone avai-

lability were perceived as very satisfactory or

satisfactory (1.5 and 1.9). Survey participants

praised ENERCON’s friendliness (1.5), hospita-

lity during visits (1.4), reliability (1.7), availabi-

lity of dedicated points of contact (1.6) and

professional competence of staff (1.5).

Most suppliers have a very active relationship

with ENERCON: 35 % of survey participants re-

ported that they were in contact with

ENERCON almost every day. Another 40 %

communicated at least once a week. In this

area as well, many answers underlined the

partnership relationship on an equal footing.

79 % of participants said that contact was in-

itiated by both sides equally.

But the survey also revealed some weak points

and areas where ENERCON needs to consider

its supplier relationships. These issues have

been analysed and discussed within ENERCON

and the results are taken into account for the

continued development of supplier business

relationships. “We achieved an excellent feed-

back rate”, says ENERCON’s Maike Günther

who was in charge of conducting the survey.

“Many suppliers called to tell us they thought it

was great that we asked suppliers their opini-

on for a change, not just customers.” The feed-

back rate was 80 %, and Günther analysed

more than 400 completed questionnaires.

Contact initiation.

Contact frequency.

Energethica(Genoa/Italy) 06.03.-08.03.20083rd Exhibition on renewable andsustainable energy www.energethica.it

EWEC(Brussels/Belgium)31.03. – 03.04.2008European wind energy conference& exhibitionwww.ewec2008.info

Energyat Hanover Fair 2008(Hanover/Germany)21.04. – 25.04.2008Technology tradeshow for theenergy mix of the futurewww.hannovermesse.de

Emder Energietage 2008(Emden/Germany)16.05. – 18.05.2008Exposition on renewable energy,energy saving technology and climate protectionwww.emder-energietage.de

New Zealand Wind Energy Conference 2008 (NZWEC2008)(Te Papa/New Zealand)08.04. – 09.04.2008Conference on “future vision” forthe industry: Emissions tradingscheme & the NZ energy strategywww.windenergy.org.nz

National Wind Energy Conference(Kalmar/Sweden)23.04. – 24.04.2008Conference on future of windenergywww.kalmar.regionforbund.se

INFO

-SER

VICE

N E W S WINDBLATT 04 | 2007 5

18 %6 %

0 % 1 %

79 %1 % 14 %

6 %

35 %

40 %almost everydayonce per month

once per week

You / your companyBoth equally By ENERCON n / a

once per quartern/aalmost never

6 WINDBLATT 04 | 2007 T I T L E S T O R Y

In November, ENERCON launched operati-ons of its very first E-126/6 MW wind turbi-ne on the Rysumer Nacken in Emden, LowerSaxony. This new addition to ENERCON’sproduct range is a sophisticated version ofthe E-112 (also with 6 MW rated power sin-ce 2005) – the world’s most powerful wind

turbine to date. To enhance performance,the rotor diameter has been increased to127 m – 13 m larger than the rotor diame-ter of the E-112. Not only has the rotor dia-meter been increased, but the hub heighthas also been taken up another eleven me-tres to reach a towering 135 m. In addition

to these modifications, theE-126 now features the newENERCON rotor blade profilewith the extended trailingedge designed to boost out-put now also in the multi-megawatt category. “We’vesignificantly increased theperformance of our largestturbine”, says Rolf Rohden,Head of the New Technolo-gies department at WobbenResearch & Development inAurich. Compared to the E-112, yield is expected to ri-se at least another 35 %. Onthe Rysumer Nacken, the E-126 should produce approx.20 million kWh p.a. –enough to supply 5000 fourperson households with clean energy.

Despite the huge dimen-sions of the new wind turbi-ne, it is easier to transport

than its predecessor. One of the decisiveadvantages is that the rotor blade is madeup of two components, a shorter steel sec-tion and a longer GRP section, which can betransported separately. While transportationfor the E-112 involved organising complica-ted road blocks, long stretches with policeescorts and special preparation of routes, inparticular enlarging curves by laying outsteel plates, sawing off branches, deliveryof an E-126 is similar to the E-82 series.“Despite their size, we can still transport allE-126 components on trucks measuring amaximum of 4.40 m in width”, reports RenéWolf from ENERCON Logistics Dept., incharge of the transports to the Emden site.

20 years after the GROWIAN (“GRoße WInd-kraft ANlage” – big wind turbine) had to bedisassembled following a series of technicalproblems, the E-126 is the first large windturbine to again use metallic material for asignificant part of its rotor blade design. TheGROWIAN had a metallic support structurecovered by GRP in order to give the aerody-namic shape. However, in the 1980s thestep to a 3 MW wind turbine was too earlyand inevitably the project failed. Nowadaymuch more knowledge and experience aswell as sophisticated design tools are avai-lable to support the R&D engineers and toallow for unconventional designs.

Another première is the fact that ENERCONinstalled a wind turbine of these dimensionson a precast concrete tower. The E-112 waseither mounted on in-situ concrete towersor steel towers. The E-126 tower in Emdenis an overwhelming 131 m high and con-sists of 35 concrete sections manufacturedby WEC Turmbau Emden GmbH situated onthe South Quai in Emden. Due to the 14.5 m

Prototype of E-126

Operation of ENERCON’s first E-126/6 MW took off in November thisyear. Currently the world’s most powerful wind turbine, the E-126 is asophisticated version of the E112/6 MW. A larger swept area, the newENERCON blade design and a higher tower are intended to greatlyenhance performance. To facilitate truck transport to inland sites, theenormous blades are now divided into two sections. And the E-126produces more electricity than the consumption of 5000 households.

World’s most powerful windturbine installed near Emden

Mounting steel segment of third rotor blade.

diameter at the tower’s base, the first eightsegments are divided into three parts fortransport purposes. 22 of the segments arehalf-divided, and the other five are in onepiece. The top segment supporting thenacelle is made of steel. The tower wallsare up to 45 cm thick, a new record forENERCON. And a total of 110 m³ of concre-te were used to build the tower. Since theground along the silty banks of the Ems Ri-ver is quite soft, a total of 64 fifty-six-centi-metre thick piles measuring an average of25 m had to be rammed into the ground tosupport the foundation. Another 1500 m³concrete and 180 t of reinforcing steel we-re used in the foundation.

The hood on the new nacelle is now madeof aluminium instead of the usual GRP. Thissignificantly reduces fire loads. Aluminiumalso has better cooling properties and iscompletely recyclable. Metal componentsare easier to fit which simplifies assemblyand saves installation time. Since the Em-den site is quite exposed to the wind, it wastoo risky to hoist the rotor hub completelyassembled with blades. Too much surface

would have been open to the wind and, forinstance, made inserting the bolts quite dif-ficult. So the erection team opted to lift twopre-assembled blades in the horizontal posi-tion to mount them on the blade adapters.For the third blade, the steel section was lif-ted vertically first and mounted. After thatthe rotor was turned anti-clockwise andthen the GRP section hoisted horizontally in-to position. “We’ve had good experiencewith this technique. However, the rotor isnormally sup-posed to behoisted as oneunit”, says JörgZimmermann,the co-ordina-tor of the ENERCON in-stallation teamsin Aurich.

ENERCON willsoon be instal-ling a secondE-126 directlynext to the first

one on the Rysumer Nacken. Both turbinesare part of a research and development pro-ject in which ENERCON will be testing va-rious storage systems in combination withthe multi-megawatt wind turbines. More E-126 are planned to follow: One turbine isto be erected at the DEWI-OCC test site inCuxhaven this fall. In 2008, five other turbi-nes are scheduled to be installed – in Ge-orgsfeld near Aurich, in Hamburg Altenwer-der and in Estiennes in Belgium.

T I T L E S T O R Y WINDBLATT 04 | 2007 7

Moving rotor into place in stator.

Crane lying on ground on Rysumer Nacken: In upright position, it measures a towering 180 meters and can lift up to 1200 tonnes.Picture: W. Fricke

8 WINDBLATT 04 | 2007 P R A C T I C E

The first five prototypes of the new 138 me-tre tower are currently being installed nearHilchenbach in Siegerland on one of thewestern foothills of the Rothaargebirge.Construction of the E-82/2 MW turbineswas initiated by Günther Pulte (farmer, plan-ner and owner of wind farms) and his part-ner Franz-Josef Ochs. The turbines arescheduled to take up operation at the end ofthe year at approximately 600 metres abo-ve sea level. The average wind speed in themiddle of the forest where the community

wind farm is located is 6.39 metres per se-cond.

Avid support from regionEighty-eight partners joined Pulte in foun-ding the wind farm association – Rothaar-wind GmbH & Co KG. Shares in the windfarm range from 3000 euros all the way upto 600,000 euros. “The majority of the com-pany shares are in the five to ten thousandeuro range”, says Pulte. He is proud of thecompany’s makeup. Two thirds of the sha-

reholders are from the districts of Olpe andSiegen. Twenty-seven shareholders aloneare from the community near the site: far-mers, craftsmen, businessmen, forest ran-gers, forest owners, employees, housewi-ves. Not all partners live in the community,though. Some live elsewhere but still haveroots in the region. For centuries, the forestsin the Sieger- and Sauerland regions havebeen cultivated for timber. Most of these areowned and farmed by local residents, ex-plains Pulte. Shares in forest cooperativeshave been passed on for generations andstill belong to the same families. Because ofthis, Pulte advertised amongst the membersof these cooperatives and found interestedparties living in Düsseldorf or Hamburg.

Forests are ideal locations forwind farmsThe Hilchenbach wind farm is the result ofsix years of intensive planning. Until theyear 2000, North Rhine Westphalia had awind power decree in place which ruled outbuilding wind farms in forest areas. Howe-ver at that time, Pulte and several other re-gional wind energy planners were able toconvince North Rhine Westphalia’s formerMinister of the Environment, Bärbel Höhn, ofthe absurdity of these limitations. “Forestsat higher regions are often just monocultu-re woods. What makes these so worth pro-tecting? Sixty-five percent of the district ofSiegen is made up of wooded areas. As faras ecology and landscape are concerned,undeveloped spaces are more importantthan coniferous woodland. Open spaces aremore vulnerable and have to be protected”,Pulte argues. Convinced by this argument,Ms Höhn amended the decree. Thus in2001, the way was paved for the wind tur-

138 metres tower

Germany’s low mountain ranges are full of excellent wind sites. Still,most of these remain undeveloped. This is because the windy moun-tain ranges are generally wooded and in many regions, forests areoff limits to wind project planers. But wooded areas are excellent sites for developing wind energy. Conservationists, wind farmowners, forest owners and forest offices are convinced of this – theexample being Hilchenbach in the Rothaargebirge. To boost the performance of the five E-82 turbines located there, ENERCON deve-loped a 138 metre precast concrete tower – the tallest to date!

High performance turbinestowering above treetops

Günter Pulte (2nd from right) with the directors of two timber co-ops which lease the site.

Pict

ure:

Achi

mAs

bran

d

P R A C T I C E WINDBLATT 04 | 2007 9

bine “Ewiger Fuhrmann” in Kreuztal-Littfeldwhich set the example for planning the Hil-chenbach wind farm.

“The decisive factor for successful planningwas that I not only approached the authori-ties but also got the local political represen-tatives and residents to jump on the band-wagon”, reports Pulte. The wind farm inHilchenbach even gained the support of thelocal FDP. With the FDP votes, Hilchenbach’scommunity council decided to chip in on thecommunity wind farm. Pulte: “Despite limi-ted funds, the council still wanted to at leastshow token support.”

Impetus for 138 metre towerBefore the project took off there was a mi-nor downside. For a while, there were dis-cussions about routing the extension of theA4 motorway across the ridges of the"Lümke” and “Drei Buchen” mountains,exactly where the wind turbines where sup-posed to be installed. Furthermore, theneighbouring community on the other sideof the ridge was starting to have its doubts.So, the site for the turbines had to be mo-ved further down the slope, slightly belowthe crest. Since, taking the planned hubheight into consideration, the mean speedwas lower here than on the crest, Pulte putforward the idea of building a taller tower.

Instead of the originally planned E-70 ma-chines with 113 metre towers, the E-82 tur-bines on 138 metre towers are now expec-ted to compensate for the lower amount ofwind.

Sloped site a challengeThe terrain at the Hilchenbach site is rathersteep. “To transport the tower and otherbulky components to the site, we have totackle several steep slopes, some up whichhave an incline of up to 20 %”, reports And-reas Giesler, ENERCON project manager.“Not only are the slopes a challenge, butoutside of the levelled crane platforms andinstallation areas, there are no proper stor-age areas.” Installation at Hilchenbach wasquite a task for the teams to master. “It ta-kes between four and five days just to shiftthe 600 tonne crawler crane (total height150 metres) within the grounds. Anotherparticularity is that the rotor will not be hoi-sted as one unit, but each blade will have tobe mounted individually.”

ENERCON has been able to demonstratethat although installing wind energy in fore-sted regions is a challenge, it is not only fea-sible but also profitable and environmentallyfriendly. When the new North Rhine-West-phalia (NRW) state government came intopower in 2005, they promptly amended the

decree and again declared wooded areas asout of bounds for wind developments. In re-lation to the number of inhabitants, the sha-re of wooded areas in NRW amounts to justabout as much as in Berlin argued EckhardUhlenberg, Minister of the Environment. Fo-rests are a vital commodity and preservinglarge contiguous forest tracts, especially inrespect of nature and landscape conservati-on, is essential. As a result, sites in NRW fo-rests remain barred to wind energy. Accor-ding to the NRW government, a project suchas Hilchenbach would have no chance ofbeing approved today.

Wind power decree conflicts withcommunal planning authority Pulte was fortunate that he had already ob-tained the building permit for Hilchenbachbefore the change of government. However,he regrets the fact that the immense poten-tial for wind energy in the wooded areasaround his home town, Kirchundem, re-mains untapped.

“The wind power decree encroaches on thecommunities’ planning authority”, he feels.He hopes that one of the communities willeventually dare to challenge the decreeagainst wind power in forested areas. Pulte:“I’ve discussed this with expert attorneysand former employees from the Office ofthe Environment. Experts argue that thedecree encroaches on communal planningauthority and that if it came to litigation, thecase on the side of the decree would be ra-ther shaky.”

Pulte does not feel that installing a commu-nity wind farm on the territory of a timberco-op could harm untouched nature but rat-her sees it as a continuation of preservingthe ancient traditions of sustainable forestryoperations. “Together, the inhabitants workthe land as a means of subsistence.” He al-so points out that in order to compensatefor the ecological effects, extensive measu-res are being taken to create buffer zones,amongst other things by creating five hec-tares of mixed birch forest. And a third ofthe cleared areas are also being restoredand replanted.

Hilchenbach: Tower construction with a 600 ton crawler crane.Pi

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10 WINDBLATT 04 | 2007 T E C H N O L O G Y

“In the past, we have worked on individualresearch and development systems, for in-stance in Utsira, Norway. But this is the firsttime ENERCON has implemented centralcomponents of its wind diesel technology ina commercial project”, says Rolf Rohden,head of New Technologies at Wobben Re-search & Development (WRD) in Aurich,Germany.

ENERCON combined three E-33/330 kWwind turbines with the existing diesel gene-rators to create a power supply system forthe island. A fibre optic cable was installedbetween the wind park site and the powerplant in Stanley to enable the transfer ofwind park data within the SCADA monito-ring system. “All system components are

controlled from a central operating unit inthe Stanley power plant”, explains SauravBaidya, developer of the power manage-ment system software. It continuously cal-culates the optimal balance between thediesel generators and the wind energy con-verters (WEC). “Our target parameters aresecure grid operation and minimum fuelconsumption”, explains Baidya.

Wind – an infinite energy sourceon the Falkands Staff in the Stanley power plant switch onthe diesel generators or disconnect themfrom the grid, according to the stipulatedparameters. “The control unit provides staffwith full control over all components in thewind diesel system”, Baidya emphasises.

The new wind farm is located in Sand Bay,an uninhabited area at the mountain foot-hills. “With an average wind speed of 10.7 m/s, Sand Bay is an ideal location fora wind farm”, says Glenn Ross, Power Sta-tion Manager in the Falklands Public WorksDepartment. The Department started takingwind measurements as early as the 1970s.Their goal was to identify sites with particu-larly strong winds. The Island Governmentwanted to reduce their dependency on oilimports. “Most energy alternatives are pos-

On the Falkland Islands, a wind diesel system has been installed thatsecures the power supply for the Eastern island. The wind energy isgenerated by three E-33 wind turbines that have been in operationsince October. They are located in Sand Bay, 10 km west of the islandcapital of Stanley; diesel generators located there supply the remai-ning power. A control system, installed by ENERCON, integrates windpower and diesel equipment and thus minimises fuel consumption.The current system configuration allows the generators to save onaverage 20 % of fuel, compared to previous consumption.

3 x E-33 Wind Diesel System

Wind reduces fuel consumption on Falklands

Glenn Ross (left) and Prince Edward, Earl of Wessex, talking to the ENERCON team. Generator room in Stanley.

Two out of three E-33 in Sand Bay.

T E C H N O L O G Y WINDBLATT 04 | 2007 11

sible, but above all it is very windy here. Wealways knew that that was the case”, ex-plains Ross.

The first measurements in Sand Bay werecarried out in 2001. The site is ideal becau-se it is very close to Stanley, whose 2200inhabitants consume most of the powerproduced on East Falkland. At the same ti-me, wind speeds in Sand Bay are 2 m/sabove the average wind speeds in Stanley.“In the past we have received several bidsfor the installation of wind farms usingasynchronous wind turbines”, says Ross.“On each occasion these were turned downas no net fuel saving appeared possible.”

E-33 ideal for small island gridsIn early 2005, an ENERCON brochure resur-faced in Ross’ office. “The depiction of theturbine control circuit indicated the possibi-lity of curtailing power output at any time.”Exactly what he had been looking for: “Onlyas much wind power would be fed into thesystem as would effectively displace fuel.”

It has taken less than two and a half yearsfor the E-33 turbines in Sand Bay to be upand running. Only the smallest model of thecurrent range of ENERCON turbines couldbe considered for installation on the Fal-klands: The island infrastructure does notallow for the transport of components forlarger WEC. But in addition, the setup withseveral small wind turbines ensures a grea-ter system stability, as the failure of one tur-bine would not immediately cut off the en-tire wind power supply to the grid.

The successful integration of wind turbineswith the existing diesel-powered systemwas another crucial aspect of project imple-mentation. “ENERCON replaced the mecha-nical speed governors of the diesel genera-tors with electronic devices”, explains IngoKleen, responsible for hardware develop-ment and commissioning of the system. Fa-ster reaction times improve grid quality, andfluctuations can be accommodated morereadily. The greatest power consumer is aquarry gravel mill; when the mill takes upoperation, the grid needs to shoulder an ad-ditional demand of 300 kW and the loadfluctuation range increases to 80 kW. “Be-fore starting up the mill, the quarry mana-ger used to call up the power plant so thatthey’d be prepared to compensate for thefluctuation. The new control equipment ta-kes care of this automatically”, says Kleen.

The Stanley power station has eight dieselgenerators with rated powers ranging from300 kW to 1.5 MW. In winter, a maximumgrid capacity of 3.2 MW is required; in sum-mer, demand drops to a minimum of

1.1 MW. To meet the demand, the genera-tors output 15 million kWh of power annual-ly and consume 4 million litres of diesel inthe process.

Savings amount to 20 % of fuelGlenn Ross expects the new wind diesel sy-stem in its current configuration to save20 % of fuel. To achieve this, the three E-33turbines need to yield an annual output of

three million kWh,a goal that has al-ready proven itselfto be realistic. SaysRoss: “We gradual-ly increased thepower set-point oneach turbine. Du-ring the day, wenow have typicallyaround 22 % of ourdemand met by thewind farm and atnight 18 %.”

Ross is particularlyproud of the fact that the Falklands financedthe project wholly independently. Over thecoming months, he is going to monitor theperformance of the wind diesel system andgather operating data. “In the long term, ourgoal is to become 100 % renewable”, saysRoss. In the short term, this will mean in-stalling additional wind turbines. A possiblestrategy for the future could involve hydro-gen production from wind energy.

According to Rolf Rohden, “ENERCON wouldbe very pleased to further support the Fal-kland Islands in their effort to increase therenewables share in their power supply sy-stem”. With the current configuration of thewind diesel system in Stanley, the windenergy share on East Falkland could reach40 %. Rohden: “To go beyond this, energystorage needs to become a part of the solu-tion. Flywheel systems and other so-calledstand-alone equipment are a part of ENERCON’s portfolio of storage technologyofferings.” The power management systeminstalled in Stanley is already prepared forthis next step.

Glenn Ross (r.), explai-ning the ENERCONpower managementsystem in Stanley toCouncillor RichardCockwell, Director ofPublic Works ManfredKeenleyside, andCouncillor MikeSummers (from left).The screens on theright display the sys-tem’s control panel(see below).

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ENERCON GmbHDreekamp 526605 AurichGermany

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12 WINDBLATT 04 | 2007 I N T E R N A T I O N A L

“Due to the huge number of projects we ha-ve going on in Italy, we decided to work to-gether with a local concrete tower produc-tion firm", says Benedetto Gallina, Managerof ENERCON Sales in Frascati, Italy – a20,000-inhabitant city situated only a fewkilometres south east of Rome.

IANUS, a Bari-based firm, successfully wonENERCON’s tender for this project. Gallinareported that IANUS is part of the SCACGroup, one of Italy’s oldest and most expe-rienced concrete component manufactu-rers. Their main field of activity is in bridgeand tunnel construction usually commissio-

ned by railway companies. ENERCON awar-ded IANUS a contract for over one hundredconcrete towers.

Factory near harbourOne of ENERCON’s main criteria for choo-sing IANUS was its proximity to the harbourin Bari (only six kilometres away). Bari is

ideally situated nearthe majority ofENERCON’s schedu-led wind farm pro-jects in Italy. “Theharbour is also idealfor exporting the to-wers”, says Gallina.

The first project inItaly to utilise con-crete towers is loca-ted near Alberona inApulia. Here,ENERCON is instal-ling a farm with 13

E-82/2 MW. At the end of August, half of thefoundations were already completed andtwo towers under construction.

The farm was developed by Fortore Energia,one of ENERCON’s largest longest standingItalian customers. Currently, Fortoreowns/operates 40 ENERCON wind turbinesand other projects are already in the works.Gallina: “It was crucial for ENERCON to ma-ke this move on the Italian market. Whenwe supply concrete towers, we are also re-sponsible for the foundations, which meansthat we will soon be able to offer turnkeywind farm projects.”

Stella St. Martino: Three E-48turbines and a nature trailThe wind farm ENERCON completed thisyear along the Ligurian coast is especiallyappealing to tourists. As an added attrac-tion to the three ENERCON E-48/800 kWmachines in “Cinque Stelle”, the owners,FERA SRL, have also laid out a nature trail

First towers made in BariNew ENERCON wind farms in Italy

For the first time in Italy, pre-cast concrete towers were usedto erect ENERCON turbines inAlberona. IANUS, a concretefirm located in Bari only twohours drive from the site, wascommissioned by ENERCON tosupply the precast parts. In themeantime, another wind farmwas installed in Liguria in com-bination with an educationaltourist trail.

Foundation work for one of 13 E-82/2 MW turbines.

Construction of two concrete towers at ENERCON wind farm at Alberona (Province of Apulia).

I N T E R N A T I O N A L WINDBLATT 04 | 2007 13

up to the turbines. Visitors can hike to thefarm from Stella St. Martino – 10 kilometresnorth of Varazze along the Ligurian coast. Atour takes about an hour.

At “Cinque Stelle”, the hub height of the tur-bines is 56 metres: The farm is expected togenerate an annual yield of 6100 MWh.“Cinque Stelle” means “Five stars” indica-ting that two more wind turbines will soonbe added to the site. “FERA purchased theland for the wind farm and the communitywill receive a modest yearly share of thefarm’s revenue”, Gallina reports. These pro-visions entirely correlate with FERA’s philo-sophy which strives to take into considera-tion all aspects of the parties involved –administrations, landowners, environment,and the public – and create a good balance.

Initial wind assessments began in 2003.But, although the project description and re-quest ´for permit were submitted in 2004,the authorization process was unfortunate-ly put on ice at the end of 2004. Beforegranting a permit the authorities arguedthat information concerning the possible af-fect the farm could have on migrant birdsand bats was missing. So, in cooperationwith the regional Ligurian administrationand the University of Genoa, FERA launchedan exemplary bird and bat monitoring pro-gramme in the region surrounding the pro-jected wind farm. The building permit waseventually granted in 2006 and FERA wasable to take up construction.

Popular destination for tourists Since July, tourists can also make their wayup to the turbines on mountain bikes or hor-seback. Twelve informative signs are postedalong the educational trail, 10 of these aredirectly situated along the access road lea-ding to the wind farm. Two of the signs arein the centre of Stella St. Martino. They pro-vide information about wind energy and renewables, how these influence the land-scape, birds and bats, facts about soundemission, details concerning the “CinqueStelle” wind farm, information concerningthe Kyoto Protocol and global warming, gui-delines for environment conscious beha-

viour, and in-f o r m a t i o n about flora,fauna andmushrooms.

“Thanks tothe signposts,a lot of peoplehike up to thewind farm atthe week-end”, explainsGallina. Theinformation isprovided inItalian, Eng-lish, German,and French. A special character was evencreated for children: “Eolino” simply ex-plains how wind energy and other renewa-ble energy systems work or what the KyotoProtocol means. “Most visitors are Italiantourists”, adds Gallina. School groups andlocal residents from towns and villages inthe vicinity also enjoy the nature trail.

Dedicated engineersFERA SRL stands for Fabbrica Energie Rin-novabili Alternative. The firm, with offices in

Milan, Albisola (Liguria), Vada (Toscana) andNoto (Sicily), was founded by a group of ex-perienced and dedicated engineers whoseobjective was to develop wind farms in Ita-ly and promote the use of renewable ener-gy. The company has already installed windfarms in various regions around Italy, a so-lar power plant with 100 kW rated power inBergigi (Liguria) as well as a hydropowerplant near Milan. Their aim is to install over100 MW rated power by the year 2010.

FERA has combinedthe wind farm con-struction with a cam-paign for social welfa-re: “Each turbinesupports a child”, isthe motto. With eachturbine installed, FERAsponsors a child in thethird world. The motivestates, “Gaining energyfrom the wind neverleads to the type ofconflicts people go towar for.” If, with everywind turbine installed,at least one childwould be offered betterliving conditions and agood education, milli-ons could soon overco-me hardship.

“Cinque Stelle”: An educational trail leading to the wind farm explains renewable energies.

Tower segment production at IANUS, Bari.

14 WINDBLATT 04 | 2007 S U P P L I E R

Roller bearings consist of an inner and outerring, a number of rolling elements and a ca-ge in which they rotate. Good roller bearingsare characterised by their running precision,the smooth operating sound, as well as per-fectly calibrated outer, inner, and bore dia-meters. Each roller bearing has to be exact-ly of the same size, and the air gap clearanceprecisely adjusted to specifications.

Before they are placed into the inner andouter rings, the roller bearings are first har-dened in furnaces and then shaped withgrinders. Next, a ribbon cage made of har-dened steel plating is put into position. Andfinally, the elements are evenly distributed

between the rings before the bearings areriveted together.

“At SKF, quality is top priority in all phasesof production”, says Walter Ragaller, spo-kesman for the Schweinfurt-based SKFplant. All precision machines used to turn,grind and hone rings are equipped with theappropriate test measurement systems.“Quality is achieved through systematictests carried out between each step as wellas other inspections.

The Swedish firm, SKF, is represented inmore than 130 countries. In 1929, Norma,the German plant, merged with other roller

bearing manu-facturers to formthe “VereinigtenKugellagerfabri-ken” (United ballbearing manu-facturers). And in1953 the com-pany was rena-med SKF Kugel-l a g e r f a b r i k e n(SKF ball bearingmanufacturers).Since then, them u l t i n a t i o n a lcompany has

evolved into a one stop provider of sophisti-cated moving element technology with41,000 employees worldwide. In addition toroller bearings, SKF also offers lubricationsystems, seals, mechatronics, and technicalsupport service. Their principle customers,besides the energy sector, are heavy indu-stry and machine and vehicle construction.

ENERCON has been an SKF customer eversince it was founded. “Roller bearings play adecisive roll in ENERCON’s gearless system.Quality and durability have to meet theENERCON standard. SKF has always ensu-red quality on a long term basis and for lar-ge quantities”, says Oliver Smidt, PurchaseManager at ENERCON Mechanic in Aurich.

The two firms have also cooperated in spe-cial developments. For all turbines largerthan the E-40, SKF optimised their bearingsaccording to ENERCON specifications. “To-day we use the specially designed doublerow tapered roller bearings to fit the axialthrust into the rotor hub. This componentjust barely resembles the original SKF rollerbearings”, reports Ragaller. Due to a hugedemand from the wind energy industry, SKFhas launched a four year expansion pro-gramme for their roller bearing production.Investments have reached the multi-millionEuro mark.

SKF administrative building in Schweinfurt.

A new metal working lathe prepairs rings for the bearings.

SKF at Schweinfurt/Bavaria

Bearings for millions of rotationsWind energy is the second largest market for roller bearings made atthe SKF manufacture in Schweinfurt. Through extreme precision andinnovative processes, the enterprise founded in Gothenburg in 1907by Sven Wingquist (inventor of the roller bearing), provides its steelproducts with the necessary durability and flexibility. The rotor hubsin ENERCON wind energy converters rotate around the axel pin onroller bearings manufactured by SKF – year after year, with utmostreliability.

I N T E R N A T I O N A L WINDBLATT 04 | 2007 15

Miyako Island/Japan

Okinawa is Japan’s island prefecture. It con-sists of a string of coral islands 3 hours flightsouth west of Tokyo, with Yunaguni Islandbeing the most western point located only100 km from the coast of Taiwan. The is-lands are beautiful holiday resorts. But everysummer Japan is hit by 15-25 typhoons ofvarious strengths. Most of these pass overor affect the islands in some way. Several ofthe strongest typhoons in the world have hitthe islands within the past decade.

For nearly ten years now, ENERCON windturbines have been in operation on severalof the islands. The installed models rangefrom the E-26/E-30/280 kW through the E-40/500 or 600 kW, to the E-66/1.8 MW.“In November, we finished installing four E-44/900 kW on Miyako Island”, reportsJørn Kristensen, ENERCON Sales Managerfor East Asia. “These are the latest modelsof the medium size wind energy convertersfor IEC Wind Class I, using the new and veryefficient ENERCON rotor blade design.”

Because of the typhoons, wind energy is acomplicated issue on the islands. The Japa-nese Renewable Portfolio Standard provi-des renewable energy quotas. Thus, Okina-wa Electrical Power Company (OEPC) hasan obligation to generate a certain amountof electricity from renewable resources. Andfor the island’s geography, without possibi-lities to use hydro- and geothermal power,wind energy is the most obvious source.

The target for wind energy is acapacity of 3 GW for all of Ja-pan by 2010. OEPC is expec-ted to install 50 to 60 MW.Most of the capacity will be in-stalled on the main island. Se-cond comes Miyako Island.

The main power supply onMiyako Island comes from twooil fuelled power plants. “The-re is one station with a totalcapacity of 21.5 MW, consi-sting of generators rangingfrom 2.5 to 5.5 MW. A second station hasfour 10 MW generators”, says Kristensen.Thus, the total capacity on the island untilNovember was 61.5 MW. After the installa-tion of the ENERCON turbines the installedwind energy rose to 4 MW corresponding to6.5 % of the total capacity. “Today, the re-newable quota on Miyako is higher than inmost other parts of the country.”

After Maemi, a one-in-hundred-year typho-on, destroyed the entire island’s wind ener-gy converters four years ago, this new farmnow consists of ENERCON turbines only.“The reason for this is that ENERCON’stechnology is well-suited for island grids –due to its high class grid performance”, ex-plains Kristensen. By using ENERCON GridData Acquisition and the SCADA system, aclosed-loop control regulates phaseangle/reactive power, active power, voltage

and other features that help to stabilise we-ak island grids. Additionally, the power fromthe wind turbines can be regulated not toexceed electricity consumption.

In Japan, there are 50 Islands with theirown grid ranging from 100 kW to more than60 MW of installed capacity. Only 16 of the-se islands make limited use of wind energy.“If all the islands used ENERCON Wind Die-sel/Stand Alone systems or made maximumutilisation of ENERCON grid control fea-tures, there would be significant savings infuel consumption”, states Kristensen. Asexperience in other parts of the world hasshown, under Okinawa wind conditions atleast 20 % fuel could be saved by installingwind turbines and appropriately integratingthem into the grids. Kristensen: “Japancould produce much more electricity thantoday, without any CO2.”

In November, ENERCON finished rebuilding a wind farmwhich was destroyed by typhoon Maemi on the JapaneseIsland of Miyako in September 2003. The new farm con-sists of four E-44 wind class I turbines, helping the regionalutility Okinawa Electrical Power Company to fulfil its goalsfor renewable energy.

Rebuilding of a wind farm destroyed by a typhoon

Karimata, Miyako Island: three out of four E-44 turbines.

WINDBLATT

Members of the operating association, Leo-vind AB, named the wind farm “Båtskär” af-ter two of the four islands – Stora and LillaBåtskär meaning “Big” and “Small prow”.The name alone already suggests the chal-lenge the assembly teams had to meet:How to get the building materials to thesharp craggy skerries with no jetties?

ENERCON first transported the E-70/2.3 MWturbines to Mariehamn by ship. From there,direction was taken over by Åland’s Vinder-negi Andelslag, an association holding 20 %shares in “Båtskär” with approximately1350 investors. Managing director HenrikLindqvist found an Åland shipping companywith extensive experience in transport around the archipelago. They were able toferry all the material ranging from concreteall the way to the rotor blades to the islandson pontoons. “Construction was only heldup two or three times when the pontoonshad to turn back due to rough seas”, reportsENERCON project manager, Sven Dressler.

One of the main conditions for the construc-tion of the turbines was that no rock was al-lowed to be dynamited. So in order to obtainan even surface, foundation builders had topour a layer of concrete up to 80 cm thickon the rock. Once levelled, a special founda-tion requiring much less concrete was builton these surfaces. The procedure used lessthan a third of the usual amount of concre-te needed for a gravity foundation. To balan-ce out the foundation, 14 post-tensionedtendons were then installed and secured inthe underlying rock.

ENERCON’s project in Valsneset, Norwayserved as a model for Båtskär. However,here the foundation has been even furtheroptimised: “Amongst other things, we repla-ced the cast-in-place steel ring with a boltbasket so we needed one third less concre-te than in Norway”, says Dressler. The ad-vantage of rock anchoring is that when theturbine has reached the end of its lifespan,the terrain can easily be restored. Dressler:

“We remove the concrete and only leavebehind the holes which are filled with soil.”

Finland provides no power purchase price.Investment grants of approx. 30 % are onlyavailable for projects on the Finnish main-land. “The only support we get from there isa negative energy tax of 6.9 €/MWh. That’swhy our turbines are only cost-effective atsemi-offshore sites such as Båtskär”, ex-plains Lindqvist. Roughly 16 km of deep seacables had to be laid. According to Lindqvist,the increased yield will compensate for theextra expenses for cable and sea transport.

Åland’s grid has two connections to themainland: a 110 kV cable to Sweden and a45 kV cable to Finland. Including Båtskär,there are now 22 WEC on the archipelago.“We already meet a quarter of our energydemand with wind energy”, says Lindqvist.“With our next project, a 20-MW farm plan-ned for the southwest tip of the main island,we’re going to lift up this share to 45 %.”

Between Sweden and Finlandlie the Åland islands, consistingof over 6,500 skerries and is-lands. Leovind AB chose fourperimeter islands to install six E-70 turbines. In October, inau-guration took place on a muse-um ship anchored at the capitalMariehamn. The “Båtskär” windfarm is planted on rock islands,the smallest being no largerthan the size of one and a halffootball fields. Situated 6 kmaway from the main island“Fasta Åland”, material andcomponents had to be broughtover to the sites on pontoons.

Åland: ENERCON wind turbinesonshore offshore

With an average wind speed of 9.4 m/s (at 65 m hub height), Båtskär is an ideal site for wind energy use.

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