Offshore Wind Energy and Civil Engineering in Germany – A Green and Sustainable Partnership Carsten Ahrens Jade-Hochschule, Zentralverband Deutscher Bauingenieure (ZDI), Germany World Council of Civil Engineers (WCCE), Spain Abstract The contribution of wind power plants to green and sustainable energy is increasing rapidly worldwide. More and more wind power plants in Germany “go offshore”. Some German construction companies go offshore, too. Their involvement in the offshore energy sector is to do normal civil engineering work like piling down the fundament tubes. But economical and ecological reasons demand a new method, which takes into account rough soil conditions and the unbearable acoustic impact on marine mammals. This new method is a vertical shaft drilling method and will be brought into the offshore energy market by the German companies Hochtief and Herrenknecht. Introduction – European Background In spring 2010, European and international climate experts at PwC, the Potsdam Institute for Climate Impact Research and the International Institute for Applied System Analysis published 100% Renewable Electricity – A roadmap to 2050 for Europe and North Africa. The report examined the potential for powering Europe and North Africa with renewable electricity exclusively by 2050. It set out a serious of financial, market, infrastructure and government policy steps that would need to occur if such a ‚what if’ vision was to be achieved [1]. The European Wind Energy Association (EWEA) published in its latest reports, see also table 1: Till 29 November 2011 over 141 gigawatts (GW) of offshore wind energy capacity is built, under construction, consented, or planned in Europe: enough to power 130 million average EU households. These wind farms - representing 35 times more capacity than the just under 4 GW installed today - would provide 13.1% of Europe's total electricity production. EWEA has been analysing all existing offshore wind power projects in 17 EU member states, mostly in north-western Europe. New offshore wind farms with a capacity of 5.6 GW are currently under construction in the UK, Germany and Belgium. It estimates that offshore wind energy offers the growth and jobs that Europe desperately needs.169,000 jobs in the EU offshore wind energy sector are expected to be created by 2020, going up to 300,000 by 2030, according to the EWEA report. The wind energy sector’s contribution to GDP till 2020 will have increased almost three-fold. If the industry were a Member State, it would rank 19th in 2020 in terms of its contribution to EU GDP, above Slovakia and just below Hungary, and the number of jobs will go up by over 200% to reach 520,000 by then, says the report. European companies are currently global leaders, with over 99% of the world's installed offshore capacity in European waters. Areas for growth in offshore wind energy include turbine and turbine component manu- facturing as well as substructures, vessels, electrical infrastructure including high voltage subsea cables, and ports. However, the new report warns that if the Table 1: Offshore wind power generators in Europe offshore wind energy sector's potential is to (online, under construction, consented, planned) be fulfilled in Europe, it is imperative that 1 sufficient levels of financing are brought in by investors. Also crucial are the financing and building of offshore power grids in the northern and Baltic seas, which would enable huge amounts of electricity to be transported to consumers. For the industry itself, there is a risk of a high-voltage subsea cable shortage in the next few years which has to be addressed urgently, says the report, as well as a possible shortage of trained workers. "The offshore wind energy sector can replicate the success of the onshore wind technology development, which is now a mainstream source of power competitive with new coal and gas plants, and a major European industry", said Zervos. "However, to ensure this happens, EU-decision-makers need to set ambitious renewable energy targets beyond 2020, invest more in research and develop offshore grid". Future Development and Status in Germany “We are becoming more and more aware of the climate change that we humans have caused. At the same time, we are worried about the security of our energy supply. For this reason, we must make our energy supply viable for the future and place greater emphasis on energy Entwicklung der Offshore- efficiency and renewable energies. Windenergienutzung in Deutschland Offshore wind power deployment Therefore, with the Renewable Energy Sources Act the in Germany Federal Government is pursuing the goal of generating at least 12.5 % of Germany's electricity needs from renewables by 2010, and at least 20 % by 2020. Ausbauziele und Ausbauszenarien To achieve this goal, the enormous potentialExpansio nof t aoffsrgethores and expansion scenarios Ziel der Bundesregierung ist es, den Anteil erneuewindr- Nach dpowerem bisher generationnur Einzelanlagen imustns Meer bein tapped. The aimTh eis Fe dtoera l Government is aiming to increase the Whereas to date, there have only been a few isolated barer Energien an der Stromerversorgung bis 201construct0 unmittelbare r offshoreNähe zur Küste windgesetzt w parksurden, wer -with a total capacitypropo roftion of pow er generated from renewable offshore plants situated in the im mediate vicinity of auf mindestens 12,5 % (eine Verdoppelung gegenü- den ab 2008/9 die ersten Windparks in Nord- und energies to at least 12.5 % by 2010 (double the level the coast, from 2008/9 the first wind farms are due to ber dem Jahr 2000) und bis 2020 auf mindesten20,000s Ostsee e n-ts t25,000ehen. Mit Inkr amegawattfttreten des Infrast rinuktu rthe- North and Balticof th eSeas year 200 0 ) and to at least 20 % by 2020. The be built in the North and Baltic Seas. The entry into 20 % zu erhöhen. Das Bundesum weltministerium planungsbeschleunigungsgesetzes wurden die German Environment Ministry is rather more opti- force of the InfrastructurSeTIF TPU NlGanning Acceleration Act by 2030. These can cover around 15 % of Germany's O F F H O R E hält es sogar für möglich, einen Anteil von rund 25 % Netzbetreiber verpflichtet, für alle Offshore-Anlagen, mistic, and believes that a level of 25 % is achieva- obligated grid operaWtIoN DrEsN EtRoG IEensure grid connection zu erreichen. Bezogen auf den Prim ärenergieelectricity- mit deren Er rineeds.chtung bis z um 31. Dezember 2011 ble. It is envisaged that renewable energies will for all offshore plants for which construction has verbrauch soll der Anteil der erneuerbaren Energien begonnen wird, die Netzanbindung sicherzustellen. account for at least 10 % of primary energy con- com menced prior to 31 December 2011. By that date, im Jahr 2020 mindestens 10 % und im Jahr 205 0 Mit Abl auf dieser F rist könnten Offshore-W indparks sumpti on by the y ear 2020, aFig.nd at le1:ast 5Offshore0 % by offsh owindre wind f apowerrms with an o utput of around 1,500 mindestens 50 % betragen. Thismit ewouldiner Leistun ggive von etw risea 1.500 MtoW ians tahighlylliert und innovative branch2050 .of developmentM W could b ein in sGermanytalled, and prod u[4]ction capacity die Produktionskapazitäten so ausgeweitet worden should have expanded sufficiently to enable high Die Windenergie wird dabei zukünftig mit einemindustry,sein, dass awhichb 2011 jäh rwouldlich ein re gcreateelmäßiger Z jobsu- especially in theIn fut ucoastalre, the contri b ution made by wind power is levels of regular annual growth from 2011 onwards. Sch werpunkt bei der N utzung von Offshore- wachs auf hohem Niveau möglich sein sollte. A m expected to rise continuously, primarily thanks to the By the end of 2020, conservative forecasts predict an Windenergie einen stetig wachsenden Beitrag lefederali- Ende des Länder.Jahres 2020 kö Itnn tewouldn bei Zugr ualsondelegu nenableg us to reduceuse oGermany'sf offshore wind pow e r. By 2030, the proportion installed offshore output of between 7,000 and sten. Bis 2030 soll der Anteil der Windenergie an dedependencer konservativer Anna honmen eenergytwa 7.000 bi s imports10.000 M W and keep electricityof elect ripricescity genera tiunderon from w incontrol.d power is t o be 10,000 M W, while cautiously optimistic scenarios Stromerzeugung von jetzt rund 5 % auf mindestens Offshore-Leistung installiert sein. Verhalten optimi- increased from its current level of around 5 % to at predict an installed output of up to 12,000 M W. The 25 % (onshore: 10 %, offshore: 15 %) steigen. Dab ei stische Szenarien gehen von bis zu 12.000 M W aus. least 25 % (onshore: 10 %, offshore: 15 %). An instal- German Government is also abiding by its long-term sind offshore 20.000 bis 25.000 M W installierter Darüber hinaus hält die Bundesregierung an ihrem led offshore output of between 20,000 and 25,000 target of up to 25,000 M W by 2030. Leistung bis 2030 möglich. Der dann mögliche jähIr- amLang fconvincedristziel von bis zu 2 5that.000 M Woffshore bis 2030 fest. wind energy will thusM W is becomepossible by the yaea rmajor 2030. The ppillarotential a nofnu- energy supply in the 21st liche Stromertrag wird auf 85 bis 100 TWh geschätcenturyzt ”, see figure 1. These words are given byal eS.lectr icGabriel,ity yield from oformerffshore wind Germanfarms is esti- Environment Minister [4]. und entspräche damit ca 15 % des Stromverbrauchs mated at 85 to 100 TWh, accounting for approxima- in Deutschland im Bezugsjahr 1998. tely 15 % of Germany’s electricity consumption in The political statement and possible wishes arethe r efunderpinnederence year 1998. by the actual status and the detailed prognosis for the offshore wind power development as described in table 2 respectively figure 2 [2]. Installed No of WEA Power 2500 16000 verhalten kumulierte ) [MW] optimistischer Leistung 14000 W Ausbau M ( 2000 cautiously cumulative ) n 12000 W ) o optimistic output Total Germany 55 215,3 i ) t M W expansion ( c W M u g ( r M t n r ( 10000 u s e t u 1500 n s w i a o o e North Sea 33 164,5 b c p L u w Z 8000 e e e t v r i n r e t e l Baltic Sea 22 50,8 i h a l l a c u i 1000 u u l 6000 r n m m h n u u ä k j A c under ca.