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Small CHP units reducing cost of some power in Yakutat, Wasilla
Two Alaska Native village corporations have installed the latest in Japanese manufactured micro-combined heating and power or CHP units in commercial buildings and have seen 50 percent reductions in electricity costs, officials with both corporations say.
Matthew McDaniel, CEO at Yak-Tatk Kwaan, said the village corporation at Yakutat, southeast of Anchorage on the Gulf of Alaska, purchased and installed units powered by propane and sized at 5 kilowatts and 10 kilowatts for two small commercial buildings the corporation owns in the community.
Power costs for the buildings were reduced from 55 cents per kilowatt hour, the rate charged by the local utility, to between 9 and 12 cents per kilowatt hour, McDaniel said.
The first unit was installed in late 2014 and the second in early 2015, and Yak-Tatk Kwaan has more than a year of operating data.
McDaniel said the corporation has been so pleased with performance that it signed up to be a distributor for Yanmar Energy Systems, the manufacturer. A subsidiary, Kwaan Energy, was formed to do marketing.
Units sold in Asia, Europe Yanmar, with more than 100 years of manufacturing history, has been selling the CHP units in Asia and Europe for years and more recently its smaller units, like that installed at Yakutat, in the U.S., McDaniel said.
The Japanese company recently rolled out a larger 35 kilowatt CHP unit powered by natural gas and the first of those to be installed in North America went into operation in July at the 17,000-square-foot Trans-Alaska Building in Wasilla, which is owned by Knikatnu Inc., the corporation for the Native village of Knik.
Tom Harris, CEO at Knikatnu, said 19 cents per kilowatt hour was being paid to Matanuska Electric Association, but cost are expected to drop to about 9 cents per kilowatt hour based on costs Knikatnu has experienced so far.
“In our first partial-month we’re on track to pay $2,000 less per month for energy,” at the Trans-Alaska Building, Harris said. The savings could be higher, too.
Fueled with natural gas or propane While fueled with natural gas or propane, Harris said the 5, 10 and 35 kilowatt units contain inverters that convert DC power to AC. A building can therefore remain connected to the local grid and taking power, with the Yanmar unit operating simultaneously as both a primary cogeneration system and backup generation. The Yanmar CHP unit can also feed surplus power back onto the grid, if there are agreements for this with the utility.
An automatic transfer switch installed with the 35 kilowatt CHP unit can take the Yanmar unit on or off the grid as needed, allowing the CHP to serve as a backup generator in case of a grid blackout, Harris said.
The units also capture waste heat to create176-degree hot water at 43 gallons per minute for storage or circulation throughout the building’s hot water heating system, to lower heating costs as a bonus as part of the reduced power costs.
McDaniel said the small-sized units are appropriate for small buildings like those at Yakutat, while the 35 kilowatt unit is sized for larger, medium-sized buildings.
Fuel cost a concern One concern is the price of the remote village fuels. An obvious market for the Yanmar units would be for buildings in rural Alaska, Harris said. However rural propane costs are often as high as $12 a gallon in many communities due to propane deliveries being limited to smaller 100 pound bottles.
Kwaan Energy looked closely a Yanmar CHP installation at Emmonak, a coastal village in western Alaska, Harris said. The Emmonak propane costs were too high, because only 100 pound propane bottles were delivered to Emmonak.
In Yakutat, Yak-Tatk Kwaan purchased 5,000 gallon bulk orders and was able to get propane costs down to below $3 a gallon by negotiating for delivery in larger containers, Harris said. If larger containers could deliver propane in rural communities costs would be reduced there, too.
Compact size Meera Kohler, CEO of Alaska Village Electric Cooperative, agreed that the propane supply cost is crucial for rural applications and also said that extreme cold weather experienced in some rural areas could affect the propane.
Despite these issues she in intrigued with the technology, Kohler said. “The compact size of the units, low maintenance and low noise level are very attractive,” she said.
Mary Ann Pease, an energy consultant who has worked on propane projects, said “The aggregation of fuel purchases, which can be realized through aggregation between communities, agencies and native corporations,” could result in lower costs.
She cited the U.S. Park Service’s national contract with AmeriGas as an example of how cost savings can be realized through aggregation.
“I was pleasantly surprised when I visited Denali Park with my family over Labor Day weekend and saw the (Park Service’s) 12 new propane buses, which were joining the park’s shuttle and transit fleet to reduce sound and carbon emissions,” Pease said.
- TIM BRADNER
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