By Sun Hao, Ren Xuemin and Tang Qian from CCSI

In recent years, in addition to dealing with global warming and controlling carbon emissions, the increasing demand for energy has to be met. Thus, making great efforts in developing renewable energy becomes an inevitable trend. With significant environmental benefits, wind power is a low-cost approach to obtain green low-carbon energy and has attracted global attention because of its great development potential. It has been the new energy project that develops fastest in the world. Currently, China has issued the relevant policies clearly encouraging and supporting the development of wind power projects. With the increasingly improved associated industry chain and the gradually lowered construction costs, wind power has a broad development prospect.

Opportunities come with risks

The construction of offshore wind power farms falls within high-risk operations. Offshore operation environment is complex. During construction, the working plane is limited, and facilities are relatively highly concentrated. Therefore, there are a great number of complex, uncertain factors during operations, imposing high risks on offshore wind power farm construction. Such high risks are mainly manifested in the following aspects.

(I) Risk of natural environment

● Meteorological disaster

Offshore wind power construction projects are affected by meteorological disasters, e. g. salt mist, thunder & lightning and typhoon. The frequent typhoon in summer in China's coastal areas has significant negative impact on the normal operation of wind power farms. Extreme weather, e. g. tropical cyclone, will form transient extremely-high wind speed, destroying the equipment and structures in wind power farms. Thunder and lightning may cause electrical circuit faults, fire and other accidents in wind power farms. Ocean salt mist has great effects on the tower of the offshore wind turbines, and, especially, the corrosion caused by salt mist is much faster than that caused by terrestrial environment.

●  Marine disasters

Any storm surge, tidal wave or any other marine disaster that occurs in the seas where wind power farms are located will directly affect the construction and operation of offshore wind power farms or even destroy the projects. Strong wind waves will also shorten the service life of the wind power farm. Additionally, ocean pollution, coastal erosion and other incidents may cause wind turbines’ operation failure. The submarine wind turbine foundation causes local submarine morphology to change, and submarine morphology may move under the action of sea currents, tides, wind waves and other factors, affecting foundation stability or even threatening the safe operation of wind turbines.

●  Geological hazards

Geological hazards can be mainly classified into two types, i. e. the hazard to seabed stability (e. g. submarine slide, submarine scouring and submarine invasion) and the seismogeology hazard (e.g. marine fault and seismic surges). Either sea earthquake or the secondary disaster triggered by the sea earthquake may cause destructive damage to offshore wind power farms.

(II) Construction process risk

●  Risk of equipment transportation

As the site of offshore wind power farm construction is at sea, all equipment and components have to be transported from land to the locations of offshore wind turbines for installation at sea. Marine transport is affected by weather, sea condition and the navigation conditions of ports and wharves. Any accident occurring during transport may cause equipment damage or other adverse results.

●  Risk of construction quality

The construction of offshore wind power projects is implemented at sea, which means highly difficult construction. For the hoisting of large, heavy articles, the hoisting height is in excess. There is the risk of pile sliding if pile driving is located at the place with poor seabed geological conditions. Offshore wind power foundation structures are complex, and the requirements of submarine cable laying construction process are high. The installation and control accuracy requirements of offshore wind turbines are high. The tightening torque requirements for jointing high-tensile bolts to turbine towers are strict. The quality of installing electrical equipment under offshore environment must be high. The quality of manufacturing and installing high-voltage cable connectors must meet high standards.

●  Risk of construction safety

Safety accidents may occur during offshore transportation, heavy lifting, personnel's entering/leaving working platform, working at heights and offshore electrical tests. There are also the problems of insufficient construction ships, incomplete construction equipment types, etc. Offshore wind power engineering structures are complex, and cross operation and construction are frequent.

●  Risk of construction equipment

Large, special equipment is required for offshore wind power construction, e.g. pile hammers and lift-on/lift off ships. Equipment is concentrated, and its use is costly. Therefore, the reliability of construction machinery is of great importance. Inadequate maintenance or misoperation may lead to the damage of construction equipment during operation and further under-construction project damage. The resultant resetting costs are high. During the construction of offshore wind power projects, a lot of ships are gathered in the wind farm, and thus the risks of coordination are high. The established mechanisms of keeping distance and communications between ships are improper. There are risks of the collision between ships and the collision between ships and the completed wind turbine foundation structures. For self-elevating installation platform, there are the risks of ship pile punch-through and tilting.

As the number of constructed offshore wind power farms grows rapidly, the supply of the current domestic offshore construction equipment cannot meet the demand, and China's large offshore equipment operation capacity cannot meet the demand of upsizing wind turbines. The supply-demand gap cannot be filled in a short time due to the long manufacturing period and high technical difficulties. The gap directly leads to the situation where a large number of equipment that cannot meet the relevant requirements is used during actual operation; meanwhile, some equipment even operates in an over-limit manner, which increases operation risks.

(III) Risk of personnel management

●  Risk of management system

The offshore wind power industry is one of the emerging industries in China. Currently, many units from other industries have started participating in the offshore wind power construction gradually. These units have not established a complete well-adapted offshore wind power construction management system in terms of management methods, management organization structures and management systems. Some development and construction units, design units, manufacturers of main engines and supervision units, general construction contractors and other units have different understanding about and requirements of the management systems for offshore wind power construction projects. The ambiguous risk management systems result in uncertainty and risks in offshore wind power construction project management.

●  Risks of human resources

Offshore wind power construction projects involve multiple specialties, including offshore engineering, ship engineering and power engineering, and have high requirements of participants' abilities and quality. Domestic offshore wind power development has a short history, and the participants of offshore wind power construction are mainly from traditional power industries. If the personnel participating in offshore wind power construction projects have insufficient or even no experience and capabilities, the risks in offshore wind power construction projects will be increased.

Imminent risk control

According to data statistics (2010 to 2015), the compensation pay-outs of the European insurance market for the construction period of offshore wind power projects exceeded 100 million British Pounds, and the average amount for each claim reached 1.85 million British Pounds. The single claim amount for offshore wind power farms is large. Though there is no typhoon or any other huge disaster in Europe, the largest claim amount exceeded 20 million British Pounds.

In these years, there were several severe offshore wind power risk accidents in China. On July 14, 2017, at the north of Huanghai Sea, Binhai County, Jiangsu Province, the L1 platform 35kV cable at the offshore boosting station of Binhai North H2 (400MW) Offshore Wind Power Farm Engineering Project was deflagrated, and 19 workers jumped off the station to survive. 18 workers were rescued, while one worker was missing. On August 22, 2017, affected by Typhoon Hato ("Tiange"), "RONG XIANG 66" encountered dragging anchor and control loss; the ship hit the 02# wind turbine foundation of Zhuhai Guishan Offshore Wind Farm, causing flooding in and sinking of the cargo hold. 11 persons fell from the ship into water, among whom 5 died, 3 were missing and 3 were rescued. The accident caused a direct economic loss of about 12.46 million yuan. On July 4, 2020, during the operation at the Jiangsu Rudong Sea, as pulling out the pile of the "ZHEN JIANG" installation platform failed, the hull could not be lifted, and watertight doors could not be closed, resulting in backward flowing of sea water to the cabin and the overall water immersion of the ship. On September 13, 2020, during the installation at the monopile foundation construction site of an offshore wind power project in Shanwei City, Guangdong Province, the boom of “YU HANG QI ZHONG 58” was broken off. In May, 2021, the semi-submersible ship “ZHAO SHANG ZHONG GONG 1” for the construction of an offshore wind power 200MW project in Jiangsu encountered an accident, resulting in hull fracture. As marine construction environment is complex, under the context of installation rush, omissions tend to occur at the links including production, construction and management. For some installed equipment that has not been used for long, accidents, such as the flooding in the platform and the fracture of crane booms, occur. All these above are wake-up calls to us when we are intensely working hard on the offshore wind power projects in 2021.

In mature European wind power markets, against the characteristics of offshore operation, the mechanism of marine surveyors has been introduced for risk control. Through the risk management by professional marine surveyors, the construction party is urged to fulfill design requirements, and the safety management level of the owner is upgraded. The mechanism of marine survey personnel is the characteristic of high-risk marine engineering construction insurance. In Europe, professional surveyors undertaking offshore wind power marine survey have been arranged. For different construction stages and construction processes, such as pile foundation construction and submarine cable construction, there are different marine surveyors responsible for survey. For important stages, risk survey and inspection must be implemented by designated marine survey personnel, and the risk survey report will be the basis for the possible claims for loss in the future.

Innovative mode, the key for advancement

In Europe, there are professional marine survey companies providing service for offshore engineering projects currently. China's offshore wind power insurance is still at the primary stage, and there are no marine surveyors. However, as time goes by, insurance companies have to face with the payments of claims and risk accumulation and thus may refuse to release underwriting capacity. China's offshore wind power engineering insurance will face the situation of the lack of underwriting capacity.

The owners of China's wind power projects generally cannot accept marine survey, which was found during the re-insurance arrangement for China's wind power projects. Additionally, the companies providing marine survey in Chinese market are mostly foreign-funded or international companies. These companies are troubled by the problems, such as costs and "difficulties in acclimatization", and thus are inevitably restricted during its service for Chinese market. Therefore, the promotion of localized marine survey service is urgent. In March 2019, China Classification Society (CCS) signed a tripartite cooperation framework agreement with WLTW and Munich Re in Guangzhou. According to the agreement, the three parties will carry out overall cooperation for the business of offshore wind power farm facilities in terms of risk prevention, technical exchange, sharing of customer resources, market cooperation, etc. The signing of the agreement marks the recognition of international insurance industries for the offshore wind power service ability of CCS, laying foundation for the healthy, virtuous development of offshore wind power in Chinese market.

In February, 2021, when participated in an offshore wind power project in Fujian, China Classification Society Industrial Corp. (CCSI) adopted innovatively the mode of marine consultation service to assist the owner in managing and controlling the risks in the offshore construction stage, through the in-depth communication and exchange with the underwriter and the owner and the understanding of project characteristics.

Before the project construction window period, CCSI collected the technical data about the early stage of the project, used these data in combination with its experience in marine survey, identified in advance the possible risks in operation and proposed risk tips and the recommendations about prevention and control. During construction, CCSI dispatched professional technicians to visit the construction site and provide maritime consulting service for several times; these technicians implemented site survey based on the relevant standards and codes for construction machinery and ships, and provide staged tips against risks. Moreover, during the project, the technicians provided professional technical training and the check calculation for key data based on the owner's requirements. The maritime consulting service provided by CCSI contributed to the improvement of project operation methods and working procedures, and the pertinence and professional properties of CCSI's consulting advice on risks also won owners' recognition. Through maritime consulting service, CCSI strove to ensure the project be implemented under the framework conforming to the relevant standards and codes, providing guarantees for the long-term safe operation of offshore wind power farms.

The high-speed development of offshore wind power requires the care and efforts from the whole industrial chain. It is necessary for China's offshore wind power insurance industry to form its own unique style. The localization of the marine surveyor mechanism and the establishment of regulated, effective insurance market cooperation systems are important components. Only pragmatic, open-minded and mutually-trusted participants can cooperate well and achieve win-win results, steadily keeping China's offshore wind power development on course.

Contact:

Sun Hao

Tel: 022-66219656

E-mail: sunhao@ccsi.com.cn