Technology and Equipment

Keys to a successful O&M strategy showcased at HYDROVISION International 2023

Keys to a successful O&M strategy showcased at HYDROVISION International 2023
(Howard Moudy, director of operations at National Electric Coil, led an O&M workshop at HYDROVISION International 2023 in Charlotte, NC. Credit: John Engel)

With some hydropower assets surpassing a century in operation, a sound operations and maintenance strategy is critical to continued performance and safety. 

Whether the asset is new or old, however, hydropower asset owners must pursue an O&M strategy that prioritizes established protocols, according to Howard Moudy, director of operations at National Electric Coil. 

Moudy led the interactive Hydro Generator Fundamentals Workshop at HYDROVISION International 2023 in Charlotte, North Carolina, which is now underway. 

“You can’t discount time,” Moudy told dozens of workshop attendees. “But I’m a huge fan of condition-based maintenance.”

Moudy outlined key considerations for a hydropower O&M strategy, including both protocol and expectation setting, as well as cleaning procedures. 

Every asset owner should establish well-defined schedules for testing and maintenance based on age of equipment, service demands, conditions of operations, safety requirements, and OEM recommendations, he said. 

Additionally, clearly defined responsibilities, sufficient time for inspections (including the use of advanced tools, like AI), and consistent record keeping should be incorporated. Moudy said he’s often surprised to meet asset owners who can’t easily and reliably produce asset outage data and trends. 

Removing the rotor from the generator will give an asset owner the best picture of maintenance needs, though this often only occurs every 10-15 years.

Visual inspections, meanwhile, are “the most cost-effective tool” in an asset owner’s arsenal, Moudy said, provided they know what to look for.   

“Every minor or major outage, you should be doing a visual inspection,” he added. 

During a visual inspection, asset owners should look for: Pd burning, arching, bleaching; broken/loose ties; loose blocking; hardware looseness or movement; dusting/greasing; contamination; and foreign object impact damage.

Most often, Moudy said, rags are found in generators, left behind by maintenance crews. He said it’s crucial that team members understand and appreciate the importance of removing everything that is brought in to a generator during maintenance. 

Contamination is one of the biggest visual findings that will confront maintenance crews, including dust, outside materials, oil, residual from the break, and issues with insolation. Contamination acts like a blanket, holding temperature inside insulation. 

“The cleaner, the better,” Moudy advised, while also noting that a well-established protocol for cleaning expectations is key, as to not create confusion amount among crews.

When cleaning a generator, safety, thoroughness, and capabilities (cost/schedule) should be considered, in that order.

Vacuum cleaning should generally be the first step to “get as much out of there” right away, Moudy said. 

Media blasting, including walnut shell, corn cob, and CO2 (dry ice), is also an option, though asset owners should consider their specific needs. 

Corn cob is softer and tends to absorb dirt and oil. Walnut shell is more aggressive but diminishes in effectiveness. 

Today, CO2 ice blasting has emerged as the method of choice for most applications. Asset owners must be mindful of age and stability of the system due to the risk of insulation damage and coating removal. 

“If you use the wrong tool for cleaning, you could be doing more harm then good,” Moudy noted. 

HYDROVISION International 2023 is taking place now in Charlotte, N.C., U.S. It formally kicks off Tuesday, July 11 at 2 pm with the opening keynote.