150MW Intertidal Offshore Demonstration Wind Farm was Commercially Put into Operation
Built Up The Largest Offshore Wind Farm in China

龙源电力建成全国最大海上风电场

  China Longyuan built up the largest offshore wind farm in China

 

  China Longyuan Power Group Corporation Limited today officially announced, with completion of the 50MW Phase II construction of Longyuan Jiangsu Rudong 150MW Offshore (Intertidal Zone) Demonstration Wind Farm, this 150MW Intertidal Offshore Demonstration Wind Farm was commercially put into operation. In Rudong County, Longyuan Power, with its 32MW (intertidal zone) pilot wind farm locally situated that became operational at end of September, 2010, has built up the largest offshore wind farm in China, having a gross installation capacity of 182MW. In China Longyuan continued its leading position in offshore wind power industry.

 

  After the completion of Longyuan Jiangsu Rudong 150MW Offshore (Intertidal Zone) Demonstration Wind Farm, it can feed about 375M.kWh power to the grid per year, with more than 2,500 hours of wind power available time. The power price is just RMB 0.778/kWh, showing high economic benefits. As compared with conventional coal-fueled power plant, it can annually save about 110,000 T standard coal, while reduce 247,000 T emissions of carbon dioxide, representing not only social benefit but significant contribution to local environmental system.

 

  As China’s first offshore wind power project, Longyuan Jiangsu Rudong 150MW Offshore (Intertidal Zone) Demonstration Wind Farm was officially approved by the National Development and Reform Commission on December 6, 2010. That Project is located on the offshore area of Rudong County. Wind turbine foundations are constructed with two technologies – single-pile and multiple-pile brackets. For Phase I of 100MW capacity, 17 Sinovel wind turbines with 3MW each and 21 Siemens wind turbines with 2.38MW each were installed. Construction works were kicked off on June 21, 2011, and Phase I became operational by year end. For Phase II of 50MW capacity, 20 Goldwind wind turbines with 2.5MW each were installed. After 4 months of construction, Phase II was started to commercially generate power on November 23.

  To underpin the initiative of “New Energies-Oriented Enterprise Transformation” determined by China Guodian Corporation in recent years, Longyuan Power has geared up its efforts in wind power development. So, Longyuan Power spear headed into the offshore wind power market, harvesting lots from its input and exploration there.

  Mr. Xie Changjun, president of Longyuan Power, stated that, Longyuan Jiangsu Rudong 150MW Offshore (Intertidal Zone) Demonstration Wind Farm would not only serve as a scout for China’s wind power industry to harness offshore wind energy in terms of wind farm site identification, planning and engineering, and construction as well, provide a testing platform to perfect the Made-in-China offshore turbines, but also set up precious references for further large-scale development of offshore wind power in China. 

  

  The Nature Challenge did not Cramped Longyuan’s Construction Schedule

  From July to August, the anticipated best period for the construction activities of Phase II of Longyuan Jiangsu Rudong 150MW Offshore (Intertidal Zone) Demonstration Wind Farm, three typhoons “flocked” into Rudong. The installation of 2 wind turbines, which was originally scheduled at early of August according to the changes of tidal level, was so delayed for half month, imposing large pressure on construction team to meet the timeline.   

  Affected by the moon, tide rises and falls twice one day, and the rising and falling moments of the second day will postpone respectively for around one hour as against that of the first day, forming a cycle of 15 days. To ship the equipment during tide rising moment and carry out installation activities after tide falling, construction team had to adapt their working hours according to the changes of tidal level. Moreover, since the huge barge is moving slow, coupled with the changing tidal levels, effective construction time was shortened and broken down into several segments. It means every minute was essential to the crew, and they had to precisely plan all jobs. Because it is quite possible that the desired tidal level disappears just a few minutes before the end of one job, leading to one entire day delayed. The Nature challenges our construction team. 

  The challenge did not let Longyuan people fall back, but sparked their wisdom. By improving the pile-driving and lifting technologies, construction team not only sped up their pace, but lowered the cost with higher quality acceptability.

  To construct the most robust foundation within tight schedule, construction team took all time available to install the single-pipe pile accessories while barge was moving around. Barge movement and accessory installation were simultaneously conducted, largely minimizing the pile driving time. Higher efficiency was achieved at no expense of project quality; contrarily, pile-driving technology was increasingly upgraded. For Phase II, the verticality of single-pipe pile foundation has been improved to within 1‰ from the average of within 2‰ of Phase I, making this technology stand top globally. Currently, international offshore wind power developers generally use “single-pile + transitional section” technology to construct the each single pile. To save cost, construction team found their edges in the construction of single pile foundation – no transitional section needed. This innovation, just for grouting operation of the transitional section, can save over RMB 400,000 for each turbine. Thus, approximately RMB 8 million was saved for Phase II construction, showing high cost-efficiency.  

  In the aspect of lifting operation, construction team completed the pre-installation of electrical system inside bottom tower drum on barge deck while barge was moving. Meanwhile, nacelle assembly was also completed on deck. So, after barge was moving to the desired position, the lifting operation of nacelle was performed systematically, dramatically minimizing the lifting time. On August 20, construction team seized the high tidal level opportunity to extend their installation time, and completed the driving operation of single-pipe piles for two turbines – Goldwind #1 and #20. In August, constructions of single-pipe pile foundations of totally 10 turbines were completed successfully.

  Thanks to our innovations in pile-driving and lifting operation, Longyuan Offshore Wind Farm Construction Speed – “one day for one pile, and two days for one turbine”, was created.

  

  First Mover Forges Experiences

  Longyuan Jiangsu Rudong 32MW Offshore (Intertidal Zone) Pilot Wind Farm cost Longyuan Power 16 months to complete its construction, equivalent to 2MW installation completed by one crew per month. For Longyuan Jiangsu Rudong Offshore (Intertidal Zone) 150MW Demonstration Wind Farm, Phase I of 100MW took three crews 5 months, equal to 6.3MW installation completed by one crew per month; while Phase II of 50MW just took one crew 4 months, creating a miracle of 12.5MW installation completed by one crew per month. And the installation speed was over six times increased as opposed to that shown at the time when offshore wind power development was initially commenced. Rome is not built in one day. Actually, as the first mover, Longyuan Power has long input substantial efforts and resources into that.

  In June 2009, Jiangsu Rudong 32MW Offshore (Intertidal Zone) Pilot Wind Farm was commenced. As the first offshore wind power project undertook by Longyuan Power, it was in the limelight then within the field. Because it carried significant meaning to China’s future in offshore wind power development.

  At that time, Longyuan Power had no large barge like today’s, nor any reference. Construction team almost “stayed” on sea everyday, in order to as soon as possible familiarize themselves with the offshore hydrometeorology and find the optimal construction program. Their efforts were paid off. Ultimately, they determined the cable route, construction program and transport plan for main equipment like wind turbine. With all those endeavors, Longyuan Power established its construction technologies in offshore wind farm at intertidal zone, and explored the way to build offshore wind farm compatible with the Chinese coastal hydrometeorology, geology and onshore characteristics. On September 28, 2010, the pilot wind farm was commercially put into service.

  Though the commercial operation of the globally first ever offshore wind farm built at intertidal zone was amazing, the construction technologies were not so desirable as expected and the construction period was too long. And then existing technologies and program opened no way for large-scale development of offshore wind farm. To build a turbine foundation at intertidal zone, concrete foundation needs 20 days, 10 days for multiple-pipe pile, but single-pipe pile solution can greatly increase the construction efficiency. To prove that, Longyuan Power determined to make massive application of single-pile driving technology in the 100MW Phase I of Jiangsu Rudong 150MW Offshore (Intertidal Zone) Demonstration Wind Farm.

  There was no reference at all, both domestically and globally, for Longyuan Power as the first pioneer. The verticality of the first two single-piles driven both deviated far from industrial standard, failing to satisfy normal operation of wind turbine. Some foreign experts asserted that, the technologies then available would never work to effectively control a less than 6‰ verticality. However, Longyuan Power came up with a new solution that, piles could be driven to the standard requirements, so long as foundation pile was kept naturally vertical. Longyuan Power immediately proceeded with their third single-pile driving, but under doubtful eyes.

  On August 13, 2011, several hundreds-ton heavy single-pile of over 50m long and 5m in diameter was driven down more than 40m beneath the earth, after over three thousands of hydraulic impact within over two hours. But deviation was controlled precisely within 2‰. That’s the first time of single-pile driving operation up to industrial standard, marking that Longyuan Power has mastered the core technology for large-scale development of offshore wind power.

  To meet the project schedule, Longyuan Power on a continual basis readjusted their working activities according to the tidal rising and falling, with all crew members camped on vessels. With painstaking efforts made by three crews, 100MW Phase I became operational by 2011 end, making the technical solution for large-scale development of offshore wind power.

  Offshore use-right for 75 wind turbines was authorized to Longyuan Jiangsu Rudong 150MW Offshore (Intertidal Zone) Demonstration Wind Farm. Through rational planning, only 58 turbines have achieved the designed capacity of 150MW. To fully utilize the offshore use-right granted, Longyuan Power decided to put up the other 17 turbines. So that generation capacity can be enhanced but with no extra requisition for offshore area, which reflected the development philosophy of “scientific sea exploration and sea area utilization improvement”, dramatically raising the wind energy efficiency of each sea area unit.

  

  Technological Innovation also Builds Brand

  Longyuan Power has succeeded in several technical breakthroughs in the construction of offshore wind farm. 22 inventions and utility patents have been registered with the State Intellectual Property Office, including “offshore intertidal zone wind power construction equipment”, “steel pipe pile driving equipment”, and “steel pipe pile driving construction method” and so on. The “research in key construction technologies for offshore (intertidal zone) wind farm project” filled the technological vacuum of China in the field of offshore (intertidal zone) wind power development. Besides, as evidences Longyuan achievements in offshore wind power development, Longyuan Power has been awarded the Class B Science & Technology Prize by China Electrical Power Construction Association, Class A Science & Technology Prize by China Association of Construction Enterprise Management, Class C Science & Technology Prize by China Water Transportation Construction Association, Class A Prize for Scientific Achievements by China Electrical Power Construction Association, Class A Prize and Class B Prize respectively for electrical power enterprise management innovation achievements, as well as one construction process incorporated into China Electrical Power Construction Methods.

  Prizes and honors have always encouraged Longyuan Power to strive forward for a better brand-effect in offshore wind power sector, growing into an industry-wide benchmark for offshore wind power development.

  Technology is “the hardest bone” for offshore wind power development. Two problems confronted with Longyuan Power on its way to make a brand new breakthrough in single-pipe pile technology: shoal wind power development was just at its theoretical research stage worldwide before this Model Wind Farm project, without any actual experience; construction at intertidal zone entails special construction equipment, and the shoal land within intertidal zone is quite soft, the seemingly “hard” shoal land will immediately become mushy just after several trampling. Such shoal land does not suit operation of heavy machineries. Just a few meters deep water can make the conventional construction barge stranded, a real bottleneck for large-scale development of offshore wind power. Either core technologies or special equipment is indispensible. As the first mover, Longyuan Power has to find its own way.

  With due considerations to the daily tide rising and falling, water level changes, and the effective construction time, Longyuan Power, after over two years of study and testing, determined its solution – “transport equipment and move the barge during tide rising time, and stop barge to install equipment after tide falling”. Flat-bottom construction barge was specially designed and manufactured for construction, making it possible to carry out installation activities at intertidal zone, also a worldwide innovation. Meanwhile, the management also took innovative actions to better coordinate all construction processes, e.g. pile driving, lifting, transport, commissioning and so on. 

  The construction of wind turbine foundation was also a quite pressing task for the construction crew. Longyuan Power was committed to R&D and manufacturing of special ships while a team was set up to theoretically study the feasibility of single-pile driving method. And Jiangsu Longyuan Zhenhua Marine Engineering Co., Ltd. was specially established by Longyuan Power and Shanghai Zhenhua Heavy Industries Co., Ltd., dedicated to professional manufacturing of offshore construction equipment. S-800 heavy-duty hydraulic hammers were purchased from IHC Holland. Furthermore, Longyuan Power ordered more than twenty special ships, such as cable ship, disanchor boat, lifting ship, and transport barge. On May 18, 2011, Jiangsu Longyuan Zhenhua Marine Engineering Co., Ltd. delivered its first 800T 360-degree slewing lifting ship for offshore wind farm works, on which a 360-degree slewing lifting system with 800T capacity and IHC’s S-800 hydraulic hammer were equipped. That lifting ship was designed and manufactured specially according to the characteristics of China’s coastal hydrometeorology, and can be extensively used for the construction activities carried out at the intertidal zone and shoal area in China. It was the top one special ship in China in terms of lifting capacity and pile driving performance at the intertidal zone. Its service in that Model Wind Farm project has reduced about 25% of cost needed by offshore wind farm construction. Currently, Longyuan Power boasts of special construction equipment that can satisfy construction activities simultaneously undertook by three offshore construction teams. Our annual construction capacity has reached 200 – 250MW, well equipped for large-scale development of offshore wind power.

  From the 100MW Phase I construction, Longyuan Power has completely mastered the single-pile driving technology. For example, the force of each hydraulic strike, the precise calculation and control of pile verticality based on actual geological conditions etc have become the core technologies for Longyuan Power to develop offshore wind power. At 8:28am of August 31, the last strike on #6 pile renewed the world record of pile verticality previously kept by Longyuan itself, with a new record of 0.12‰. It only took Longyuan Power one year to attain that prideful achievement since the first attempt in offshore pile driving. Up to date, Longyuan Power stood nationwide as the sole wind power operator who has the technology for large-scale application of single-pile driving operation.

  Through years of exploration and study, Longyuan Power has set up its databank regarding the marine, hydrometeorology, geology and weather at the intertidal zone of China. Moreover, a professional construction technological system has been formulated with full consideration to the difficulties and risks possibly encountered by offshore wind farm construction, creating its strengths in human resource, technology, equipment, and experiences for offshore wind power development. Longyuan Power, through that Offshore Model Wind Farm project, has paved the way for the development of offshore wind energy.

  Mr. Xie Changjun noted that, Longyuan Power’s technology in single-pile driving was now on a par with the global industrial leaders. Single-pile driving technology and special heavy-duty equipment have reduced the cost in wind power project at the intertidal zone, substantially improved the cost efficiency.

  

  Never Slack off Efforts in Further Development

  Offshore wind power is a key sector for future wind power development. As a global pioneer in building wind farm at intertidal zone, Longyuan cumulated extensive experiences in the construction of offshore wind farm, forging a solid foundation for extensive development of offshore wind power in the future.

  Offshore wind power features rich energy resource, high wind availability for power generation, no-land requisition, no water consumption and massive scale. In recent years, EU countries and USA and other countries began to shift their wind power focus to the sea. Many wind power developer majors, equipment manufacturers are proactively exploring their way to offshore wind power market. By the end of year 2010, totally 43 offshore wind farms had been built, with gross installation capacity of 3,670MW. And 1,440MW capacity was added just in year 2010.

  China’s abundant offshore resource can provide potentials of about 200,000MW for further development in inshore and shoal areas. China advocated the development of offshore wind power in recent years. That initiative was made slightly later than the Europe, but the growth pace is rather fast. Currently, in both governmental policy and development technology, China has set firm groundwork for offshore wind power. According to the national target in offshore wind power development, 5,000MW capacity will be built by 2015, and 30,000MW by 2020.

  Grid interconnection and unbalanced regional economies are the main constraints for the development of onshore wind power. With relatively developed economies and strong grid acceptability to wind power, Chinese coastal regions are well positioned to take wind power, favorable to further development of offshore wind power. In future, offshore area will play more important role in China’s wind power development.

  The National Energy Administration called for that, large-scale offshore wind power development should be encouraged during the “12th Five-Year” period, with reference to the achievements made in offshore wind farm demonstration project. For offshore wind power development, key areas include Shanghai, Jiangsu, Hebei, Shandong, and other areas like Zhejiang, Fujian, Guangdong, Guangxi, Hainan, and Liaoning are also covered by the offshore wind power development program.

  Mr. Xie Changjun said, Longyuan Power would take this Offshore Model Wind Farm as a new starting point, grasp all opportunities to continue the development of offshore wind power, progressively implement the strategy of “offshore wind power development” from Jiangsu to all other provinces in China having commercial value for offshore wind power works, so as to open a wide way for large-scale development of offshore wind power for the whole country. 

  Looking ahead, Longyuan Power, following the corporate philosophy of “proactive but prudent, systematically plan and well coordinated development, cost efficiency”, will further fuel up the development of offshore wind energy resources with higher cost-efficiency but lower investment risk, driving forward the sustainable development of Longyuan Power.