In response to a growing trend in countries all over the world to undertake serious efforts for realizing “carbon neutrality,” the number of initiatives aimed at expanding renewable energy is increasing. The Agency for Natural Resources and Energy, too, has called for the substantial expansion of renewable energy, which was stated in the Strategic Energy Plan drawn up in 2021. In the Plan, there is a particular focus on expanding onshore and offshore wind power generation, with numerical targets being set, such as increasing onshore wind power generation to 17.9 GW in FY2030, an approximately four-fold increase compared with FY2019, and an approximately six-fold increase in offshore wind power generation to 5.7 GW.
According to the Japan Wind Power Association, a total of 2,574 wind turbines are in operation in Japan, generating 4.58 million kW of electric power (as of the end of 2021).*1 However, according to investigations by government councils and other bodies, a guaranteed operating rate of 97% is quite common in Europe, while in Japan, the annual operating rate (operating hours ÷ total hours in a year) of wind power generation equipment has been averaging 87%,*2 and even the operating rate of the equipment installed since 2011 has leveled out at 92%.*3 It is said that the low operating rate is one of the factors behind the expansion of wind power generation not moving forward.
Amidst these circumstances, Hitachi Power Solutions, which is engaged in the upkeep and maintenance of approximately 350 wind turbines, has been achieving a high yearly operating rate of 98% for those wind turbines.*4 There are various reasons behind this high operating rate, including the use of drones and AI in conducting highly precise inspections and the proper establishment of a service structure. In addition, one more reason is the “high field capabilities” of the service engineers who carry out work in the field.
Hitachi Power Solutions has nine service centers located throughout Japan, from Hokkaido to Kagoshima, where approximately 200 service engineers (as of December 2021) are actively engaged in their work. Daichi Suzuki, the business manager in charge of Wind Power Field Engineering Department, Renewable Energy Solution Division, says, “Our structure for dealing with numerous issues surrounding wind power generation in Japan and the high level of field capabilities of service engineers, and an enhanced educational and training system for raising their field capabilities even further, are all making it possible to achieve high operating rates, which are said to be among the highest in Japan.”
Maintenance is an important key to resolving various issues that wind power generation faces. Needless to say, wind power generation equipment is exposed to the harsh natural environment 24 hours a day, 365 days a year, with half of all damage and malfunctions being caused by natural phenomena. Damage to blades and malfunction of rotor shafts, generators and other components frequently occur. In many cases, damage or malfunctions are handled by replacing parts, but there are apparently some cases that require parts to be back ordered, which may take time. According to a survey conducted by NEDO (New Energy and Industrial Technology Development Organization), downtime, when operation stops because of equipment damage or malfunction, can be as long as 29.9 days per incident. This is a serious issue that must be resolved in order to ensure the stable operation of wind power generation equipment and maintain efficient generation of electric power.
On the other hand, Mr. Suzuki continued, “Hitachi Power Solutions has a Parts Center at its Onuma Works in the city of Hitachi in Ibaraki Prefecture, and also stocks parts at each service base. Furthermore, the Noshiro Service Center in the city of Noshiro in Akita Prefecture is the Company’s maintenance base in the Tohoku Region, where there is a lot of wind power generation equipment, and also stocks large-size parts, such as blades, so even in cases of damage or a malfunction, the incident can be handled promptly, making it possible to reduce downtime.” (Mr. Suzuki)
In developing service engineers, there are issues that are particular to wind power generation. Wind turns the blades, which then spins the generator, which generates electricity. This is the basic mechanism of wind power generation. But the wind turbine also incorporates various equipment, such as a controller (yaw controller) to orient the blades to face the direction the wind is blowing from, and a device to monitor the operation. In addition, there are also structures, such as a nacelle to house the generator, and a tower for supporting it.
“With regard to upkeep and maintenance of a thermal power plant, which is indoors, service engineers in various fields, such as those for the mechanical system and others for the electrical system, can gather together to handle the work. In the case of wind power generation, however, the sites where work has to be done are scattered outdoors. So, in actuality, engineers have to carry out their work individually in most cases, when maintenance or repair needs to be done.
It is for this very reason that each and every service engineer is required to have a wide range of knowledge, ranging from mechanical structures to electrical and electronics, as well as safety measures for working at high places. Unless the level of knowledge in all of these fields is raised, it will not be possible to improve the skills needed to recognize signs of potential malfunctions. It is absolutely indispensable that the skills of a service engineer be “deep and broad,” and that is precisely why it is difficult to develop service engineers. This is indeed a dilemma.” (Mr. Suzuki)
The service engineers of Hitachi Power Solutions receive an education in the form of classroom lectures and basic training at the Hitachi Training Center and the Noshiro Training Center, before being assigned to various service centers. There is a real wind turbine at the Hitachi Training Center, where the service engineers are able to have their first hands-on experience with actual equipment. After assignment to worksites, the service engineers receive training by means of OJT (on-the-job-training), where, as a rule, each newly-assigned service engineer carries out tasks at the worksite while paired with a senior colleague.
Moreover, every service engineer must receive Service Engineer Training at the Hitachi Training Center once a year. Mr. Masaaki Koishi, an instructor at the Training Center, explains, “This is because when developing service engineers, what we value above all else is the thorough implementation of fundamental actions. By going back to the basics and thoroughly learning the fundamentals, it becomes possible to acquire further advanced technical skills. In order to achieve this, regular trainings are essential.”
As space is extremely limited inside a nacelle, and work done on the outside means carrying it out at a height of dozens of meters above the ground, the level of the service engineer’s fundamental actions directly affects the level of quality of the upkeep and maintenance provided. Consequently, it is imperative that no aspect of the training, including climbing up and down a ladder inside the tower and how to handle tools, is neglected.
For example, when climbing up or down a ladder, a device to prevent a fall (harness) must be fitted to the service engineer and secured to the ladder. However, depending on how the weight of the person is applied, the fall prevention device tends to lock right away, so the person becomes unable to move.
Furthermore, just as each person has characteristics that are unique, there are areas that a worker is good at as well as not so good at. “With this in mind, we, the instructors, ascertain the disposition, and strengths and weaknesses of each service engineer, to determine which service engineer is inclined towards mechanical systems and which one is inclined towards electrical systems, and decide what to emphasize when providing guidance. By going through this every year, the service engineers are able to acquire comprehensive skills.” (Mr. Koishi)
The contents of the training for service engineers do not consist only of technical studies. The training involves a diverse range of activities, such as rescue drills and sharing experiences of close calls, which will help prevent work-related accidents. For example, a rescue drill will have a colleague put on a harness and suspended in mid-air, and the task is to complete the rescue of the colleague in under eight minutes. The reason the task must be completed in under eight minutes is that a person could suffer cardiopulmonary arrest if continuously suspended for around ten minutes. Because time cannot be wasted just waiting for an emergency services team to arrive, the drill is meticulously carried out to practice executing the rescue operations as quickly as possible.
A bolt tensioner is a tool that uses hydraulic pressure to tighten bolts, and when tightening a bolt, up to 1,520 bar of hydraulic pressure is applied. The pressure is approximately 109 times greater than the pressure a fire engine uses to spray water, so any mistake when using this tool can result in injury or worse. Therefore, practicing the proper use of this tool in high places becomes very important. Because extremely advanced operations are performed, a certification of qualification for using special tools like this bolt tensioner is required. Without a certification, use of this tool is not permitted.
The sole purpose of establishing service centers throughout Japan is to enhance the service structure in order to promptly deal with malfunctions or other issues at the facilities of customers, but at the same time, the centers also serve as the foundation for raising the skills of service engineers in the field.
“With service bases located from Hokkaido in the north to Kagoshima in the south, a wide range of know-how has been accumulated, such as measures to deal with snowfall in cold regions in winter and measures for coping with humidity in the summer heat of Kyushu. Technologies with high target value are developed and nurtured by training sessions where the accumulated know-how is shared, and experience gained in the field at various locations through personnel rotation. Carrying out such meticulous initiatives to enhance field capabilities is a strength of the Company.” (Mr. Koishi)
There is also an increase in the use of such systems as IoT, in other words, what is generally referred to as digitized services, in upkeep and maintenance. While Hitachi Power Solutions, too, has put together a service menu that emphasizes preventive maintenance, Mr. Suzuki points out, “Going forward, maintenance will increasingly make use of digital technologies. But even in such cases, it will ultimately be the field capabilities of the service engineer that will be key as a final decisive factor.”
The whole point of digitization is to reduce and assist in the workload of service engineers, and data analysis, too, must be of use in the verification of maintenance items.
In actuality, maintenance of wind power generation equipment is carried out twice a year, with master maintenance, in particular, being carried out by two workers who inspect approximately 250 items over a three-day period from April to May, when the wind is light. In the past, master maintenance involved the inspection of more than 400 items, but the results of data analysis, etc., have made it possible to reduce the number of items to the current level, enabling service engineers to make use of the time saved to focus their energy on carrying out preventive measures.
However, automation that uses digital technologies is also giving rise to problems, such as everyday tasks being carried out without an understanding of the system as a whole, or only carrying out operations by the book and losing interest in everything outside of that. In emphasizing this point, Mr. Suzuki said, “Unless people have an attitude of wanting to gain an even deeper understanding of what they’ve been taught, they won’t have the ability to respond or demonstrate any creativity if something unexpected happens. So, this is why…We do, after all, want to focus on the importance of OJT. Working together with veteran colleagues will build up a person’s practical skills and sharpen a person’s intuition. Ever since Hitachi Power Solutions first got started in the wind power business in 1996, it has spared no effort in developing and building up field capabilities. And it is because of this that we have been able to achieve such results as realizing a high operating rate and gaining the trust of customers.”
Many service engineers feel a sense of pride when they see wind power generation equipment on which they carry out upkeep work or had a hand in building. They say that contributing towards realizing carbon neutrality, regardless of how small those contributions might be, leads to a positive attitude towards work. This desire forms the foundations of the field capabilities for the upkeep and maintenance provided by Hitachi Power Solutions, and leads to a strong resolve to achieve further advances.
