contracted out or performed in house, regular maintenance of turbine systems is
integral to efficiency and reliability.
By Dan Rafter
Ed Bussiere, facilities director with Windham Hospital in Willimantic, CT, knows that his hospital has received plenty of benefits from the cogeneration plant that has been providing power to the facility since December 2008.
The plant, powered by microturbines provided by UTC Power, provides enough energy to heat and cool the hospital, something that has significantly reduced the facility’s reliance on the public power grid. The cogeneration plant also helps the hospital meet its “green” initiatives. According to UTC, the company’s PureComfort system—which is what Windham Hospital is using for its cogeneration plant—will boost the hospital’s energy efficiency from 33% to more than 80%. This, of course, will result in energy bills that are far lower than average; something that is crucial in today’s still-sluggish economy.
The system also uses the waste heat from its microturbines to produce 43°F chilled water that Windham uses for air conditioning in the hospital’s buildings. This also saves Windham Hospital more than 1 million gallons of water a year. As hospital officials like to point out, this is enough water to fill two Olympic-sized swimming pools.
But for Bussiere, there’s one more benefit that rarely gets mentioned: he and his staffers don’t have to do anything to make sure that the microturbines powering the cogeneration plant are running properly.
That’s something that UTC Power handles, thanks to the long-term service agreement that Windham Hospital signed with the company.
“Those turbines are operated and managed by UTC Power,” says Bussiere. “They take care of everything.”
When asked whether that makes his life easier, Bussiere was quick to answer yes.
A growing number of facility managers enjoy the same arrangement. They don’t have to worry about monitoring the fuel levels of the turbines providing their buildings with onsite power. They also can set aside concerns about turbine noise interfering with employee productivity. These managers don’t have to worry about whether their machines meet federal or state emissions requirements. The service agreements take care of that challenge, too. And, they certainly don’t have to worry about routine maintenance.
But not all facility managers are as fortunate. Others are responsible for the maintenance and operations of their turbines. And these managers need to know when to check their machine’s air filters, how to reduce excess noise, and how to test whether the fuel powering their machines is still fresh.
Manufacturers of turbines, though, expect the trend to point more toward long-term service agreements in the future. After all, building managers and maintenance staffers are already swamped with work, what with many businesses and municipalities still in budget-cutting mode.
The less attention these stressed staffers have to pay to turbines, the better, say manufacturers.
“Our microturbines run continuously, 24/7,” says Bussiere. “They are a good source of baseline power for us. But they have to be running right. That’s why we have that arrangement with UTC Power.”
Guaranteeing Efficient Turbines
When it comes to maintenance, every building owner or facility manager is different. Some strictly follow manufacturers’ guidelines. Others aren’t so diligent.
And that, according to Joseph Konicki, president and chief executive officer of Columbia, SC-based Primesouth, is a vital distinction.
Those owners who aren’t working with long-term service agreements need to make sure that their building managers and facilities personnel are well trained in how to care for turbines and resolve their most common issues; if they don’t, these owners will face expensive repairs—and, in the case of emissions, perhaps costly fines—in the future.
“I like to compare it to driving a car. If you drive your car in a reasonable fashion, you’ll be placing less stress on all those components. You’ll then be extending its life,” says Konicki. “If you are constantly punching the gas at every stoplight and taking off like a shot as soon as it turns green, you’ll be wearing out the tires and the transmission. You’ll be overtaxing the engine . . . that sort of thing. But if you operate your car in a reasonable fashion, your problems will be fewer. It’s the same thing when you work with turbines.”
James Crouse, executive vice president of Sales and Marketing for Capstone Turbine Corporation, says that it’s those companies ordering the smaller microturbines who tend to struggle the most when it comes to testing their turbines, monitoring their fuel storage, and conducting the regular maintenance that helps keep them running efficiently.
And it’s those owners who order the smaller installations who more frequently have to pay the bigger bills when turbines and microturbines break down from lack of maintenance.
“Part of the challenge, and not just for us but for companies selling power equipment in general, is that the smaller the installation, the less onsite maintenance staff the customer might have devoted to making sure that a turbine is running properly,” says Crouse. “Our customers who are installing 150-kilowatt or 250-kilowatt projects are not providing the same level of site expertise as are our customers doing one- or two-megawatt projects.”
That’s why Crouse considers the option of long-term service agreements to be such a good one for smaller installations. The owners behind these installations often don’t boast a large maintenance or operations staff. And the maintenance staffers that they do have are already overworked, Crouse says. The long-term service agreements can help make staffers’ lives easier while extending the life of turbines and boosting their efficiency, he says.
These agreements have grown in popularity as a growing number of smaller companies are turning to onsite power generation. Under such agreements, customers pay an extra fee to manufacturers. These manufacturers then take over responsibility for the operation, maintenance, and repairs of the onsite turbines.
These arrangements increase the odds that even building owners ordering smaller installations can maintain a turbine that runs efficiently and remains online.
“Today, we have an adoption rate for these units of about 50% of our clients signing these agreements with us,” says Crouse. “We have about 1,000 microturbines under these contracts. That’s fewer than what we want, but it’s a good start.”
No Service Agreements?
But what about those owners who don’t enjoy the benefits of a long-term services agreement? There is some good news; maintaining turbines and addressing their most common issues doesn’t have to be overly complicated.
Facility management or maintenance staff can take their own steps to help decrease the odds that their onsite turbines will fail.
Konicki, though, emphasizes that maintenance staffers needn’t spend a majority of their time worrying over turbines. These machines usually need just a bit of care to enjoy long lives, Konicki says.
“Our philosophy is a little different as far as operations and maintenance go,” he says. “We view the operation and maintenance of a unit in the context of minimizing the total life-cycle cost of a component.”
Konicki says that facilities staffers should do what is needed to make operating a turbine as inexpensive as possible throughout its lifetime. This means performing regular inspections of the devices and listening to the noises that they are making to make sure nothing seems off.
It also means calling in outside experts—usually on a quarterly basis—to perform a more thorough check of the engines. And if engines are on standby mode—meaning that they are not operating continuously—it means scheduling quarterly load tests to make sure that the turbines will spring into life when they are called on to provide backup power.
None of these maintenance and monitoring steps is overly expensive, Konicki says. And they will pay off in the long term.
“If you want your equipment to run efficiently for a long time, you need to develop those support systems—regular maintenance and tests—that allow you to minimize the intermediate maintenance costs of keeping that equipment up and running,” says Konicki. “That’s what we recommend for turbines. On the other end of the spectrum, there are some components that because of their low cost, it makes sense to simply run it to failure without ever worrying about maintenance. A lightbulb is like that. You run it until it burns out. Then you throw it away and buy a new one. That’s not how you should treat your turbines.”
One of the most critical tasks facilities managers can take on to reduce the chance of future problems with their turbines? Maintenance staffers should inspect their turbines’ air filters once every quarter, Crouse says. At the same time, they should inspect their machine’s igniter and injector.
Crouse recommends that owners change their microturbine’s air filter once a year. They might not need, though, to replace their machine’s injector and igniter as often. In general, the injectors in Capstone microturbines can operate efficiently for about 20,000 hours of uptime. The ignitors, depending on how often turbines stop and start, can last from one to three years.
Crouse also advises the owners of his company’s machines to keep their turbines clean. It might seem like a small matter, but when dirt and dust accumulate on turbines, it can lead to overheating and internal electronic damage.
“If your microturbine is operating in an area that is overly dirty and dusty, you need to clean the dust and dirt off the machine,” says Crouse. “That small step alone will extend the life of your turbine’s electronic components.”
The Importance of Testing
Testing isn’t an issue for most of Capstone’s clients, Crouse says. That’s because these clients usually run their microturbines continuously, using their turbines on a daily basis to provide power and thermal energy to their facilities. That, in effect, serves as their “testing.”
“They are tested through their normal use,” he says. “They’d know, just by running them all day every day, whether something wasn’t working properly.”
But other building and facility owners rely on turbines for standby or emergency power. These machines only kick into life when power from the public grid is interrupted. And it’s of critical importance that these machines work properly when called upon. Some of the bigger users of standby onsite power are data centers and financial institutions, owners that can’t ever be without power.
It’s not as easy for the owners of these turbines to know whether their machines are operating properly. After all, these machines aren’t humming away 24 hours a day, seven days a week. Most of the time, they’re sitting quietly.
This is where regular testing becomes essential.
John Arruda, owner and president of Turbine Marine Inc., recommends that the owners of his company’s turbines test their engines once every quarter.
That, though, is just a general rule, and there are plenty of companies that should probably incorporate regular testing of their turbines. There might be some companies that should test their turbines more often. Turbines that sit in humid environments or are exposed to harsh weather conditions, for example, should be tested more frequently says Arruda. Units that operate in areas in which salt and sand are often in the air will also benefit from more frequent tests, Arruda says.
It’s not enough, though, for owners to simply test their machines. It’s also vital that turbine owners test their engines properly. Arruda recommends that owners start their standby engines, shut them down, and then perform a vibration test. Owners should chart the temperature of their engine’s exhaust gas when the turbine is running at full load.
It can be easy for busy companies to forget about or skimp on this kind of testing their turbines. But those companies that do will end up costing themselves in future expenses, Arruda says.
“The savings from preventative maintenance and testing are huge,” he says. “Sometimes having the engine sit is worse for its parts than running it continuously.”
Noise and Emissions
Microturbines tend to be quieter than their larger cousins. In fact, Crouse from Capstone says that his company’s machines, because they operate at high speeds and set off no vibrations, are rather quiet.
Most of the noise from the microturbines comes from the air-intake or the exhaust system, he says. Building owners, if they find that their microturbines are too noisy because of this, can purchase simple exhaust silencers that muffle the noise. Capstone itself sells kits designed to reduce the noise that comes out of the company’s microturbine air-intakes, Crouse says.
Facility managers and maintenance staffers can also take their own steps to ensure that their microturbines meet all state and federal emissions standards.
All it requires is a bit of preventative maintenance.
As long as maintenance workers keep their microturbine air filters clean, their machines should easily meet emissions requirements, Crouse says. That’s because turbine manufacturers design their machines to meet these regulations as soon as they are installed.
“Our microturbines have just one moving part. There are very few things that can change the performance of the engine,” says Crouse. “Our machines are designed to keep emissions at the levels that they are designed to be at.”
For Konicki, keeping turbines running properly mostly requires common sense on the part of facility managers and building owners.
Those owners fortunate enough to have facility staffs that are diligent about taking the small steps toward maintaining turbines should enjoy engines that last for a long time, Konicki says.
“If your staffers aren’t skipping the recommended maintenance steps, your turbines should be fine,” he says. “It’s when you get people who don’t clean the filters, or who don’t know what to listen for, when you get problems.”
The key is for building maintenance workers to become as familiar with their facility’s onsite turbines as possible, Crouse says. Only then will these workers know when something is wrong with these engines.
“The more familiar with the equipment they are, the better it tends to perform,” he says. “If they know, for instance, what a microturbine is supposed to sound like when it is operating normally, they can call for service if it suddenly sounds different. If they know what it’s supposed to look like when they walk by, they can call for service if something doesn’t look right. It’s nice to have a set of eyes on the machine occasionally so if that something doesn’t seem normal, they can call and get it fixed before it breaks. It’s always less expensive to address something before it breaks.”
Turbines have been an important power provider at the Mount Pleasant, WI, site of SC Johnson & Son Inc.’s largest global manufacturing facility. In addition to new wind turbines, two cogeneration turbines have also powered the SC Johnson facility since the mid-2000s.
The cogeneration turbines produce about 6.4 MW of power each year for the facility. The site’s two new wind turbines generate 8 million kWh of electricity annually. All the turbines combined allow the facility to produce an average of 100% of its electrical energy onsite.
Jam Stewart, director of global public affairs for SC Johnson, says that maintaining and monitoring the turbines is a priority at the facility.
Facility staffers perform routine maintenance checks on the cogeneration units each month. They also perform more extensive quarterly maintenance checks on these units. The turbines are also tested every five years to make sure that they are meeting emission requirements, Stewart says. Both cogeneration units contain a Predictive Emissions Monitoring System that alerts facility staffers if the units are exceeding emission standards.
The same care goes toward protecting the facility’s new wind turbines, Stewart says.
Twice a year, the wind turbines undergo scheduled maintenance. These turbines, though, boast new technology that makes maintenance an easier task, Stewart says.
“These wind turbines use permanent magnets instead of a gear box, and hence do not need gear oil,” says Stewart. “These wind turbines have fewer moving components and a much smaller replacement parts list. As such, these are ‘low-maintenance’ machines requiring less time and money to maintain over the next 20 to 30 years of operation.”
Author’s Bio: Dan Rafter is a technical writer and frequent contributor.