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Leading the way for microgrid systems
Rural Alaska communities implementing cutting edge renewable energy and integration systems in effort to reduce diesel dependency Alan Bailey for Petroleum News
While the Alaska Railbelt has ready access to natural gas for power generation, rural communities in the state have long had to rely on the use of expensive and erratically priced diesel fuel to meet their electricity production needs. For a number of years the rural communities have been implementing renewable energy systems in an effort to displace the use of diesel with more predictably priced and affordable generation systems. The consequent need to integrate several different power sources, each with varying generation characteristics, into single microgrids for village electricity supplies has placed rural Alaska at the cutting edge of these microgrid and renewable energy integration technologies, officials engaged in rural power supplies told a meeting of Commonwealth North on Oct. 14.
Early adoption in rural Alaska Rural Alaska investigates and adopts new technologies well in advance of the Railbelt and major grids worldwide, often by decades, said Rob Roys, deployment director for Launch Alaska, an organization that facilitates the implementation of renewable energy and other environmentally friendly systems in Alaska. Rural electric utilities began incorporating utility scale wind technology into their grids as early as 1997, Roys said. By comparison, wind farms linked into the Railbelt grid did not appear until 2012 and 2013, he said.
The implementation of utility scale solar has surged in the last two year, both in rural Alaska and on the Railbelt.
Golden Valley Electric Association, on the Railbelt grid, was an early pioneer in the use of energy storage to save any excess energy as a backup power source. In 2003 the utility implemented a 26-megawatt battery energy storage system, the largest system of its type in the world at the time. Chugach Electric Association later implemented a hybrid flywheel and battery energy system. Alaska Telecom Association is currently constructing a 46-megawatt storage system, Roys said.
But the rural utilities have been more aggressive in implementing energy storage. And there are now more than a dozen utility storage systems throughout the state, Roys said.
Increasing complexity The combination of storage with an increasing variety of power source technologies has magnified the complexity of the rural electrical systems, with hydropower, solar power, wind power in various combinations having to be integrated and connected to dispatchable electrical loads in some of the most sophisticated power systems in the world. Expertise from Alaska in the advanced algorithms required for these systems is now being exported around the globe, Roys said.
For example, Kodiak has combined 31 megawatts of hydropower with 9 megawatts of wind generation, 3 megawatts of battery storage and 2 megawatts of flywheel energy storage into an electricity supply system that can operate annually with more than 99% renewable energy, Roys said.
And with more than 200 microgrids operating in the state and an installed capacity exceeding 800 megawatts, Alaska has the largest installed base of microgrids in the world, he said.
“In rural Alaska the ability to operate with no diesel online is the new standard for operations,” Roys said.
Northwest Arctic Borough’s vision Ingemar Mathiasson, energy manager for Northwest Arctic Borough, emphasized the importance of reducing rural Alaska’s dependence on diesel fuel. The borough has formed an energy steering committee that is developing a vision for the energy future for the region. The target is that 50% of energy for heating and electricity supplies will come from local sources by 2050. Part of the objective is to address climate change through the reduction of carbon dioxide emissions. Currently the borough is on track to achieve a 10% reduction in diesel fuel imports in 2020, Mathiasson said.
Projects include a solar farm in Kotzebue, a solar array in Ambler and an Ambler biomass project.
A pilot project in Kobuk and Ambler is assessing the practicalities of using reversible heat pumps for heating and cooling houses - an electrically powered heat pump, a kind of reverse air conditioner, can provide heat more efficiently than a conventional electric stove. The electricity supplies for the pumps are assisted by direct connection to solar arrays that can offset power from the grid, Mathiasson said. Despite the cold climate, it appears that people can use the heat pumps through to December, before having to switch back to conventional oil stoves, he said.
A project in Ambler, designed to assess the potential to reduce energy needs through energy efficiency and funded by the borough’s Village Improvement Fund, involves the installation of LED lighting, solar panels and heat pumps for all 70 households in the village.
Regional utility energy projects in five other communities involve the installation of various combinations of wind power, solar power and battery storage, Mathiasson said.
KEA energy transition Matt Bergan, wind farm project engineer for Kotzebue Electric Association, described KEA’s efforts to transition from diesel power to renewables, to minimize diesel use. KEA is the hub utility for 3,200 people and 11 villages in the Northwest Arctic Borough, he said.
KEA began operating a hybrid wind and diesel system in 1997 - 15 to 25% of the utility’s annual energy now comes from wind, Bergan said.
The original wind farm consisted of 19 wind turbines. However, the utility has recently replaced eight of these turbines with a solar array. Two of the turbines are large, modern units. The plan going forward is to install two or three more large turbines and complete the replacement of older, smaller turbines with solar power. A community scale battery supports the system.
The utility is able to additionally save some diesel power by selling electric heat from excess wind power to the local hospital.
Bergan sees 50% of power generation capacity as being the upper limit of renewable energy usage. Increasing renewable usage beyond that level would be cost prohibitive, he said.
Asked about the feasibility of bringing in alternative fuels to diesel, Mathiasson said that the Northwest Arctic Borough had investigated the logistics of shipping in natural gas or propane but had found this to be financially and logistically impractical using the shallow rivers of the region.
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