The Power of Micro Turbines
By Marc Donadieu
Glacier City Gazette
Hotels, hospitals and buildings running 24/7 require a considerable amount of electricity and heat. Large equipment such as boilers eventually wear down and need replacing.
But power generation technology has vastly improved since early days of boiler installation.
Micro turbine generators now produce electricity and heat while offering significant cost savings for industrial and commercial applications.
Alyeska Resort has a large demand for electricity and hot water. In 2015, two boilers were at the end of their life cycle. They were replaced with two micro turbines powered by natural gas, which prolonged the life of an existing boiler while reducing the need to buy electricity from a utility.
There were a number of elements that factored into purchasing micro turbines. The rising cost of buying electricity played a role. So did the number of times a year the power had gone out in Girdwood before the purchase was made. Guests used to be left in the dark and hot water faded until power was restored, but no longer.
Davin Blubaugh, a Senior Electrical Engineer with RSA Engineering in Anchorage, installed two micro turbines at Alyeska. The project was an interesting learning experience because it was his first time working with the technology.
“The hotel owners had a specific set of requirements of how they wanted the micro turbines to perform with the existing diesel generator,” Blubaugh said. “They wanted to be able to cover the full load of the hotel’s service in the event of a power outage.”
Micro turbines are best suited to run at full output and deliver the maximum amount of electricity and heat to a facility all the time, Blubaugh said. Building loads or power demands vary throughout the day. There needs to be spare capacity available for when the utility cannot provide power.
“Micro turbines are a great piece of equipment to have for a facility,” Blubaugh said, “especially one like a hotel that has high power and hot water load. When applied to the right facility, they’re a great way to reduce your utility bills. You’re using more of the energy within the natural gas rather than just paying for power and heat separately.”
The system must be able to transition to island mode or off grid to meet power demands. An existing diesel generator can pick up some of the load as well. All of the components have to be timed and sequenced appropriately.
“It took some time and some tweaking or fine-tuning,” Blubaugh said. “Getting the micro turbines and some existing transfer switches and diesel generator to talk to one another accordingly was probably the most challenging part of the project. We were fine tuning the system for six months to a year making tweaks to different settings inside the equipment and putting in some additional control components.”
Installing micro turbines takes two days or less, but it takes six months to a year to get the system to run optimally. The fine-tuning happened occasionally rather than continuously.
“We would learn from outages and things like that,” Blubaugh said. “We would go in there and take some of the data and talk it over between myself and the micro turbine manufacturer, and we’d come up with some different ideas. It was a good process to learn from with the control side.”
Mana Technologies CEO, Sean Nelson has a different perspective about micro turbines. His company is the Alaska and Wash. Distributer of FlexEnergy Micro Turbines. Nelson has 24 years in the electrical industry, was part owner of Yukon Electric and started Mana Technologies with a business partner Thor Kallestad about a year ago.
Nelson explained how the technology works and its design history. Micro turbines have been around for over 20 years, and the design was modified from bigger turbines at large power plants, Nelson said. Ingersoll Rand engineers started reducing size and tinkering, and Nelson says today’s design is better than what they started with. Micro turbines burn methane, propane or natural gas. They are available in 250 and 333 Kilowatt size.
“The micro turbine is like a jet engine in a box,” Nelson said. “The high-pressure natural gas feeds the micro turbine engine. As it spins, you are getting heat and electricity from that engine. Because of that, it becomes appealing to a building owner looking to extend the life cycle of the building. You could cut your energy costs to that building and also be a green energy friendly building owner as well. You have the micro turbine recovering the heat from the engine that can be used to heat a hot water line.”
While micro turbines burn natural gas, they do so much more efficiently compared to power generated by coal, Nelson said. The low emissions meet Calif. Environmental standards, which are among the most rigorous in the U.S. The decrease of carbon released into the atmosphere to generate the same amount of power and heat is attractive to building owners who look to back away from fossil fuels.
Nelson sees micro turbines as a transitioning technology.
“I’m looking at this technology as the definite future of energy,” Nelson said,“part of it, not the whole because as we move away from being completely fossil fuel dependent, there is still going to be a need for energy to come from these types of applications.”
Nelson described an industrial development that is emerging with this technology. Oilfield companies have high exploratory and start up costs to develop well sites. A micro turbine could be set up on a site where there is natural gas.
“You can run pump jacks, man camps or a whole host of items from the natural gas found on site,” Nelson said. “Those applications will allow an owner or ownership group to realize true cost savings immediately. If you have that micro turbine providing normal power and you’re also getting the heat through a recuperator from that unit, then you are maximizing everything that the piece of technology is outputting.”
According to Nelson, micro turbines exceed requirements for EPA regulation for the Clean Air Act. North Slope operators are looking for reciprocating generators that can meet the current EPA air pollution standards. The decibel level is also within Occupational and Safety Hazards Administration (OSHA) tolerance limits. If a problem arises, swapping out turbines does not take long.
“We can change out a micro turbine in a day and a half or less,” Nelson said. “It’s simply compartmentalized where you just pull it out and unhook the apparatus. Then you install the new engine, test it and you’re back up and running.”
Nelson says the public does not know much about this growing technology and what it can do. He likens micro turbine technology to early solar power, compared to where it is today. He sees similar growth and innovation in the future, especially when more businesses adopt this technology and realize its benefits.
“Going back to the conversations with the owner of the property (John Byrne, President, Managing Partner, Alyeska Ski Resort, LLC),” Nelson said, “if natural gas prices came down a little bit more, he would like to be completely grid independent.”
“He would essentially install his own power plant with micro turbines that would run the entire mountain.”