May-June 2009

Maximizing Efficiency Through Maintenance

With more demands placed on wind energy, asset owners must stay on top of maintenance needs.

Article Tools

Create a Link to this Article

By Bob Ward

Comments

Wind power is a well-known source of renewable energy and is a viable source for more environmentally friendly power generation. President Obama is bringing attention to the market by proposing a plan to ensure that 10% of the United State’s electricity comes from renewable sources by 2012, and 25% by 2025.

Towering hundreds of feet in the air, wind turbines are subject to extreme environmental forces that require turbines to be inspected regularly to determine if maintenance is necessary. A key issue within the industry is and will continue to be how to maximize a wind farm’s efficiencies while minimizing downtime. The tips of a turbine blade can reach speeds of up to 300 miles per hour, and with hail, dirt, and even rain pelting the blades, wear is inevitable. Couple that with the bearings that support the rotor and other moving parts that are subject to wear, and it is clear just how many facets of turbine maintenance are crucial for efficiency. By learning about different inspection techniques and practicing smart predictive maintenance, unscheduled maintenance and downtime can be significantly reduced, and assets will be able to run at full efficiency for longer periods of time.

Scheduled Versus Unscheduled Maintenance
Maintenance costs associated with wind turbines are typically less expensive than maintenance associated with other forms of electricity generation. Regularly scheduled wind turbine maintenance is generally done two times per year, which translates into less than 24 hours of downtime for each turbine being inspected. In a wind farm environment, only a few turbines are down for maintenance at a time, so the other turbines are still producing.

Costs associated with scheduled maintenance are relatively low, however unscheduled maintenance can have a significant impact on a company’s bottom line. Unscheduled maintenance typically means some sort of problem or defect has presented itself, so not only are there costs associated with the loss of production, but also with repairs that need to take place. Unscheduled maintenance can turn into a costly and, often, unnecessary endeavor when considering that simple schedule maintenance, also known as predictive maintenance, twice a year would often detect any potential flaws that would cause downtime.

Benefits of Predictive Maintenance
Predictive maintenance has been part of planning for other power generation businesses for years, and it’s an important issue that must be carried over to the wind power industry. As mentioned above, a good predictive maintenance plan can identify issues before they become problems that could shut down operation of a turbine, but there are other cost saving factors that result from predictive maintenance. Predictive maintenance allows wind farm owners to schedule repair and maintenance at the most economical time grouping turbines that need similar servicing together to save time and costs. 

Inspection Techniques
Predictive maintenance is a critical part of operating a productive wind farm, and it is important to understand when, where, and how to inspect turbines to best detect potential problems. With the advances in Non-Destructive Testing (NDT) techniques and equipment, inspection is a much more efficient and reliable results. The key component to almost all NDT equipment in the wind power industry is portability to make it easier to get to hard to reach areas. 

Ultrasonic inspection is used for locating delaminations in turbine blades. Using sound waves traveling through the blades or rotors at a specific speed or velocity, in a predictable direction, the waves will be reflected or transmitted when they encounter a flaw such as a delamination. 

Remote visual inspection is a great technique for identifying defects and helps inspectors identify potential problems very quickly through the use of video. Remote visual inspection is typically done with video borescopes that easily identifies pitting, cracking, corrosion, erosion, weld, and other defects that could cause unscheduled downtime. When using a video borescope, it is imperative to find models that are lightweight, have excellent light output, portable, and durable—which are all necessities when inspecting the tight quarters of a gearbox, without sacrificing image quality.

Inspection Challenges
Although predictive maintenance is critical to maximizing efficiency and minimizing downtime, there are a number of companies that are still not regularly testing and inspecting their assets regularly. Climbing to the top of a wind tower is a difficult task, and, as the average age of inspectors is increasing, it becomes more and more difficult. The knowledge and skill set that these inspectors and technicians have from years of experience are extremely valuable to asset owners. Some wind turbine designers are adding service elevators inside the tower; however, this doesn’t solve the wider problem. Older turbines most likely will not be retrofitted to include this upgrade, and they are the assets that benefit from predictive maintenance more so than brand new turbines.

Advertisement

A more cost-effective solution is to find inspection equipment that still allows experienced inspectors to review and analyze data, and software makes this possible, especially with remote visual inspection. Using a video borescope that has the capability to include menu-driven inspection software will bridge the gap between the experienced inspectors and those new to the field. Menu-driven inspection software guides inspectors through the inspection process and intelligently auto-generates reports that can be reviewed by inspectors who did not collect the data. Using a non-destructive testing data management platform will even allow images and data to be shared across multiple locations for the most accurate analysis.

Wind power is going to continue to grow as a critical power resource for the United States and for the world. Predictive maintenance is an important aspect in maximizing the efficiency of wind power, and, as the industry expands, it is important to utilize a number of different inspection techniques to ensure maximum efficiency and minimal downtime. With scheduled maintenance, small defects can be detected and corrected, avoiding unplanned downtime.    

Author's Bio: Bob Ward is Power Generation Segment Manager at GE Sensing & Inspection Technologies.

What Do You Think?

Post a Comment

Be the first to tell us what you think!

Post a Comment

Not a subscriber? Sign Up
 
 
*  
 




 

Get Distributed Energy Email Updates!

Get weekly news and updates through our Distributed Energy email newsletter!