Although gas turbines have been around since the 1940s, when they were used in aircraft, the successful employment of the technology on a smaller scale, as a “microturbine,” started about seven years ago.

Often we’re enamored by a new technology when it hits the market—the buzz, the novelty, the promises it makes to better our lives—but when it comes to being one of the first to purchase it, we tend to get cold feet. Without proven experience to back up ability to perform, it often seems like a better idea to let someone else try it first.

‘The leading manufacturer of microturbines is Capstone Turbine Corporation, based in Chatsworth, CA. “There are actually over 3,500 Capstone microturbines being used worldwide, with a documented total of more than 11,000,000 fleet operating hours,” says JT Thielman, director of operations at SeaGate Convention Centre. “This equates to over ‘1,000 years’ of microturbine fleet operation. So they have been quite well-proven for a young technology.”

Currently there are around 500 microturbines operating in California, while Japan, an early adopter of the technology, has a similar number in operation. Though less prevalent, a considerable number are  being used in the Midwest and Northeastern states. “That’s where the bulk of our units are employed, but we have quite a few others operating around the globe,” says Keith Field, director of communications at Capstone.

Lately, amidst all the big city players, the modest city of Toledo, OH, has become a pocket of advanced distributed generation. The most recent installation in Toledo was at the SeaGate Convention Centre, which became interested in the technology after seeing a microturbine begin operation the Toledo Museum of Art. The University of Toledo’s Visual Arts Center is also using the technology. 

A Whole Lotta Power
The SeaGate Convention Centre books large events such as entertainment performances, banquets, sporting events and business conventions, so it has tremendous power needs that vary from month to month. “We can’t control when our clients want to book the facility and use our resources, including our utilities,” says Jim Donnelly, President and CEO of The SeaGate Convention Centre. “Sometimes we’ll peak at the first of the month if someone rents a space then.”

The SeaGate's strategy was to eliminate peak so it could lower the demand for utility power.

Obviously, using energy entirely from the grid is expensive. “We are on peak demand with Edison, which means that at any time of the month, our highest peak for that day will set our rate for that month,” says Thielman. So the SeaGate started considering ways to cut down its energy costs.

Over the years, it has employed every type of energy saving method imaginable. “We’ve done everything we can to reduce our reliance on energy,” says Donnelly. “We changed our ballast to energy-efficient ballast and our lighting to energy-efficient lighting. We’ve had studies done by our utility provider to see how we could save.” The SeaGate has also done lighting retro-fits, installed a natural-gas-fired chiller and removed one of the electric chillers. It had also considered wind and solar energy, but neither of those applications was quite right for the facility.

The SeaGate’s strategy was to eliminate peak so it could lower the demand for utility power. It is also trying to become a green building, and finding a technology that fit with this goal was also important.

So Thielman paired with the SeaGate’s in-house HVAC guy and the two started researching microturbines. “We wanted to find a way to shave those peaks and keep more of a flat line through the months, especially in summer, and we were investigating different ways to do that. At first we considered using an emergency generator, but when we looked into microturbines we realized they were a perfect fit.”

Finding A Manufacturer
Capstone was brought to the SeaGate by BHP Energy Solutions Ltd., a distributor/engineering firm that distributes Capstone microturbines.

The SeaGate had been researching microturbines for six months before it decided to purchase them, and hadn’t really considered any distributors other than Capstone. Research revealed that Capstone microturbines were the most efficient and a good match for the center’s particular needs. They were also available and wouldn’t postpone the SeaGate’s plans for installation.

When looking for a manufacturer, the SeaGate’s main concerns were reliability and a proven track record. Capstone was the world’s first to market a commercial microturbine energy system, selling its first three units in 1998. So the SeaGate was naturally drawn to them.

“The Capstone machines are 100% American made, which is an added bonus for us,” says Thielman.

“When we ran the analysis,” says Donnelly, “we could see that there would be a 40-month payback for us. And with a grant and low-cost loan through a local state bank, we got a 1.97% interest rate for eight years. This was very attractive, especially with the 40-month payback. We figured the cost of natural gas is on the high side, so any savings that came down would just be a bonus to us.“

Before the installation, the SeaGate had recently purchased electricity in a bulk rate that was going to expire on Jan. 1, 2006. If it did nothing before then, it would’ve cost another $70,000 a year out of pocket just for electricity. So there was an incentive to save on the electric side as well as the natural gas side.

The Goods
The SeaGate is currently using four Capstone C60-ICHP microturbines. “In addition to creating 60 kW of power in conjunction with the facility’s grid connection, each unit serves as a 375,000-BTU boiler,” explains Field. “ICHP is integrated combined heat and power, meaning it uses both the electricity and heat output from a generator.

This heat exchanger is actually integrated into the product for maximum thermal efficiency, not to mention cost efficiency. It has a smaller footprint and gives you some operational capabilities you wouldn’t have with third party heat exchangers.”

The SeaGate Convention Center books large events, including entertainment performances.

These microturbines are fueled by natural gas. Capstone has other models that run on waste gases from landfills and oil fields. “The C60-ICHP has really, really low emissions. You can almost breathe the exhaust,” says Thielman. “Though we don’t recommend it.”

Capstone’s C60-ICHPs come with or without a battery. Without the battery they operate in parallel with the grid. This model uses a little grid energy to start them up, then natural gas continues to run them. The systems that have batteries, called blackstart or stand-alone systems, can start on their own.

“In a power blackout, the stand-alone Capstones’ batteries will provide more than enough power to start the systems, and then the operating system will recharge the battery for future use,” says Field.

Operation Details
Before SeaGate’s microturbines, the center had gas-fired boilers for heat and hot water. For cooling, it used one 400-ton and one 200-ton electric chiller. When the building was erected, it had another 400-ton chiller that was replaced in 1998 with a TECO Gen gas-fired chiller. The old chillers still remain in place, and sometimes they still need to be turned on when the building needs a lot of cooling.

“Now we’re running the microturbines to heat the building with hot water,” says Thielman. These units are what are called base-loaded. “They will operate at 100% capacity all the time,” begins Field. “The facility will actually use more electricity and more heat than these produce. That’s Capstone’s strategy, so that there is the fastest payback. By operating at 100% output of both energy and heat, you’re operating the systems in the most efficient manner.”

The Toldeo Museum of Art was one of the community's first facilities to install a microturbine.

Conventional generators are basically a truck engine connected to a generator. The Capstone microturbine is a miniaturized jet engine with an integrated generator. The jet engine turns the generator and creates electricity. It has inverter-based power electronics that convert high-frequency energy into grid compatible energy (480-V three-phase, and 60 hz.).

“With Capstone, you don’t need a transformer,” explains Field. “You don’t need switchgear, and you don’t need protective relays. These are all expensive pieces of equipment needed with a conventional generator, but all that is built into Capstone’s inverter-based electronics.”

So how does the cogen work with these microturbines? Any generator creates heat as well as electricity. The advantage of a microturbine is that a turbine engines draws in a lot of air and pushes out a lot of air. With Capstone microturbines, all the heat energy is in the exhaust. “There’s no need to regulate the engine temperature. These units have no radiator. They have no oil. The Capstone microturbines have just one moving part supported on air bearings that don’t need any oil or lubricants.” This means the customer does not have to replace any hazardous fluids. Because there’s only one moving part, there’s simply much less that can break down.

Operation and Output
The installation of the SeaGate’s four microturbines was completed this past November. The units are located in their mechanical room, which is on the basement level. They are about 7 feet tall and have a width and depth equal to a typical office desk. Together they produce a total of 240 kW of electric power and 1.5 million BTUs of hot water.

Before it installed the microturbines, the SeaGate knew the units would never produce enough energy to cover the entire facility—the directors were just looking for something that would shave the peaks. With Capstone microturbines, they found they could do this while at the same time provide hot water for the building. It was a simple win-win.

Each unit produces about 375,000 BTUs of heated water, so when four are used at the same time, it’s essentially the same effect as using a 1.5-million BTU boiler. “We anticipate we’ll get  74% of our hot water or heating from them, and 40% of our electrical needs,” says Thielman. “But that 40% will knock down those peaks and keep us in a lower price range for Edison. The microturbines are producing all the heat for our building now. We find that we can run these turbines all winter long, spend less, and use less natural gas to run them in comparison to the boilers we were using before.”

According to the DOE, fossil-fueled utility power plants average 33%  fuel efficiency, and the average boiler is about 80% efficient.  To get the same power and heat outputs, you have to put in 50% more fuel than you would with a Capstone microturbine.

“In addition to greater fuel efficiency, our microturbines have vastly lower emissions than utility power, according to US EPA statistics,” says Field.  “The Capstone microturbine is one of the cleanest-burning engines on the planet, needing no exhaust treatment devices or chemicals.”

Installing And Maintaining
The SeaGate’s application process for the State of Ohio grant money began in January 2005, and the installation of the first unit began in August. All four units were in place in November, and the installations did not disrupt the functioning of the business at all.

The SeaGate dealt directly with BHP Energy, which managed the project in partnership with the center. Normally, for installations, BHP does a turnkey project. But the SeaGate had its own in-house electrical and HVAC people, so it decided to use some of its employees for the installation. The logic was that it would not only be less expensive that way, but their employees would then gain knowledge of how the systems work. “We were able to install some of the piping, and all the electrical hook ups following the engineer’s specs,” says Thielman. “And instead of bidding out electrical and plumbing, we did it ourselves.”

Because microturbines have only one moving part, they are practically maintenance free. They have no gearbox, no oil lubrication, and no anti-freeze, because units are air-cooled. So the only annual scheduled maintenance the unit needs is a filter change once or twice a year.

BHP and Capstone are hooked into a computer that connects into the brains of the microturbines, allowing them to monitor them around the clock. The SeaGate has purchased the same software, and BHP is training SeaGate employees how to troubleshoot the units and make sure they’re running at peak performance.

“With conventional generators, you have to do a major overhaul at about 4,000 to 5,000 hours, which equates to about 6-7 months at full capacity,” says Field. “With Capstone microturbines, the recommended overhaul is within 40,000 hours, or about 4.5 years if you’re using them all the time. To compare the two, you have to do eight to 10 overhauls on conventional generators before you need to do just one on a Capstone.”

So How Much Are We Talking About In the Way of Savings?
The units pay for themselves but cutting the facility’s power bills, and by providing for their heat needs by offsetting the use of conventional boilers, which generally aren’t as efficient and need a lot of maintenance. “This is the most fuel-efficient way to operate, for the customer, cost-wise,” adds Field.

The University of Toledo's Visual Art Center is also using microturbine technology.

This SeaGate’s microturbines are now selling in the neighborhood of $60,000 to $70,000 dollars. A 60-kW conventional generator of the size of the SeaGate’s operating with the same parameters would cost close to that amount. However, compared to a conventional generator, the microturbines are more energy-efficient, more environmentally friendly, and save enormous costs and amounts of time in maintenance.

“The filter change takes just a few minutes in downtime,” says Field. “Conventional generator maintenance requires downtime for several hours to as much as a day.”

The SeaGate was able to get a grant from the Ohio Department of Development’s Office of Energy Efficiency, which granted it 25% of the cost. The SeaGate also secured a very low interest rate loan through a local bank to pay for another 65% of the project and put up remaining 10% itself.

“When we crunch the numbers with our consultants, we’ll probably be saving $125,000 to $150,000 annually on our energy usage though cost avoidance,” says Thielman. “The complete project cost is about $596,000 now.”

In the Midwest, there’s a high demand for heat, which the SeaGate needs for approximately eight to nine months out of the year. This actually turned out to be to the SeaGate’s advantage because it will make their payback that much quicker.

When Capstone microturbines were introduced in 1998, some of the earlier models were not quite as reliable as they are today.

“The products we make today are enormously robust,” says Field. “And far more reliable than conventional generators.”

And the SeaGate has been happy with the way they’ve been functioning on their facilities. “They’ve been exceeding our expectations,” says Thielman.

Wait, There’s More!
One issue the SeaGate faced was the question of what it would do with the hot water it produced in the summer. Unlike a hotel or airport, which needs hot water all the time, the SeaGate doesn’t. The solution it came up with was to install absorption chillers, which will be phase two of the project. The chillers will use the hot water they produce from the exhaust heat to run cooling for the building in the summer months.

The prospects of better fuel efficiency and lower emmissions are cornerstones of "green" technologies.

“We have a heavy demand in summertime for electricity because we have a lot of summertime events that require a lot of cooling. Without the absorption chillers, it would be wasted heat. We want to avoid running any electric chillers at all,” says Donnelly. The SeaGate is currently waiting for data from its consultant to make sure it can be done, and will then apply for a grant from the state. The hope is that the chillers will be in by next summer.

The SeaGate has definitely taken on the mi casa es su casa mindset when it comes to stretching the efficiency of its microturbines. There is talk in Toledo of adding an arena, which the SeaGate is hoping it will be adjacent to.  The hope is that it can add additional microturbines and save up to 5% of the cost of building the arena. “We want to become a mini power plant, if you will, to supply the energy needs for the arena,” says Donnelly.

The SeaGate is next door to the Fifth Third Field baseball stadium, and the two facilities are discussing the possibility of the SeaGate supplying the stadium with additional power for some of its electrical needs.

“Alternate energy sources are something we’re looking at for getting off the overseas oil,” says Thielman. “I think in today’s business environment, companies have to look at alternate sources of energy and the use of that energy to stay competitive. At the SeaGate, utilities are our No. 1 cost after labor, and we must be proactive with respect to that cost and not be reactive to market rate of energy. We must also lobby our elected officials to be more consumer friendly when it comes to the restrictions on the self-generation of energy. I think microturbines and other distributed forms of energy will be attractive to a lot of facility managers and will eventually give some competition to the utility conglomerates.”  

L.A.-based journalist AMY SORKIN KURLAND specializes in marketing communications.

DE - May/June 2006