Shungnak Community Microgrid Solar Project
Shungnak, Ala. | 225 kW + 384 kWh
Above the Arctic Circle, in the remote village of Shungnak, Alaska, against the backdrop of a pristine wooded landscape, residents would hear the constant sound (and smell) of a diesel-based power plant system. These generators weren’t economical or convenient either. Fuel needs to be transported into town (on World War II era planes, mind you), carrying costs that recently hit $15 a gallon.
Maybe these generators are more reliable in those frigid temperatures than alternative sources of energy? Hardly. Plant operators must check them at least three times a day to ensure they haven’t frozen over. Should a problem arise when no one is there, the system will cut itself off — an especially dangerous problem during -20 to -40 degrees Fahrenheit weather.
By the way, Alaska has over 200 communities operating on a similar diesel generator system.
Enter the 2022 Microgrid Project of the Year, funded by the United States Department of Agriculture (USDA) and the Northwest Arctic Borough. The Shungnak microgrid project represents the Alaska Village Electric Cooperative (AVEC)’s highest penetration of solar as well as the utility’s first integration of battery storage. It was installed by Alaska Native Renewable Industries and Daylight Energy Services in collaboration with AVEC and nonprofit Launch Alaska.
The 225-kW solar array + a 250-kW / 384 -kWh Blue Ion LX battery system from Blue Planet Energy enables a “diesel off” (thanks to Ageto’s ARC Microgrid Controller) that has all sorts of benefits to reduce the headaches mentioned earlier.
We’ll get to all of those benefits. But given all we know thus far, my first question for Ingemar Mathiasson with the Northwest Arctic Borough was “What took so long?”
“Well first we had to prove that solar actually worked in the arctic,” he delightfully explains. “The idea when we approached the USDA about it in Washington, D.C., was that Alaska was very dark, and there’s not enough sunlight to justify it being up there.”
Mathiasson and his team have been working to connect more renewable energy projects to enable more “diesel off” time for years. They had gathered data since 2013 on the first PV projects they were able to put in the ground to support an area water plant to show, indeed, solar is viable here.
Shungnak shares this microgrid connection with a nearby village (about 340 residents total), and the two are able to run diesel-off all the way until around 9 p.m. in summertime. “The best day we had was 11 hours straight for two villages from this one microgrid,” Mathiasson says.
Designing for diesel off
“The Alaska microgrid market is still fairly unique and small in the grand scheme, so there’s not a ton of vendors in the market,” reports Dave Messier, project manager with Daylight Energy Services, noting the average load in these villages is not too different from large estates in the lower 48.
The battery system was sized so the village could run for two hours on batteries alone. This also proved to be a good factor for time shifting.
An interesting design aspect that’s becoming more common, Messier says, is the way the batteries and battery inverter interact with the generator baseload power grid. Microgrids traditionally have one “boss” that acts as the grid forming source, and then other renewable resources are tacked on in a grid following mode. Daylight Energy Services designed a more egalitarian system, made possible by the Ageto controller, in which all the devices run in parallel.
“They are all in grid-forming mode,” Messier explains. “That allows us to bring that stored energy from the battery on and off the grid seamlessly.”
The SolarEdge PV inverters are located in a building erected to house the battery storage system. There, the system is tied to the main bus and the generator assets. The Ageto controller then works in conjunction with the generator controller to determine which assets to turn on, based on (among other things):
- How full the batteries are
- The load in the community
- How much solar is being produced.
The controllers must also be sure to save some battery power in case a generator faults and backup power is needed in a pinch. Mathiasson reports roughly a dozen such faults happened in the first year of the microgrid’s operation, including one of about 20 minutes the day before we chatted. No fault showcases the virtue of this newfound luxury like the “Christmas miracle.” Yes, literally on Christmas morning the villages were running on a single generator, which faulted, but no one noticed because the batteries switched on and kept everyone warm and jolly.
Logistics challenges abound for projects in this region of course, and they come into play for every component of the design. This is why Northwest Arctic Borough put the project out as a design-build.
“It’s always amusing to me when I talk to people in the lower 48 who are like ‘oh yeah, it was a pain in the neck to get to this spot. We had to put it on three different trucks,’” Messier jokes. “For us, there’s usually a truck to the port of Seattle and then a barge or maybe a train to get it to Fairbanks and then there’s an aircraft and that’s just to the area. Unloading is always another challenge on the other end.”
Local crews also need to be familiar enough with the components that arrive to complete the installation.
Key to the final bill of materials and microgrid design was the Blue Planet Energy battery, according to Mathiasson and Messier. Reasons being:
- Lithium iron phosphate. The Northwest Arctic Borough is hyper focused on the environmental benefits of all the new projects they are pursing. Batteries that included cobalt or lead were non-starters.
- Cold weather performance. All batteries will be sensitive to subfreezing temperatures, but the Blue Planet Energy batteries have autonomous safety controls that separate the charge current from the discharge current. “There are different temperatures at which we can safely discharge and no longer safely accept a charge, so that’s just an additional layer of control,” notes Wes Kennedy with Blue Planet Energy.
- Size restrictions. Everything must fit into a DC-6 aircraft to get it to Shungnak, which puts restrictions on height, width and weight. Plus, lithium-ion batteries are classified as hazardous.
- Less maintenance. Comparing the maintenance of any solar + storage system to the diesel generators spinning constantly at 500 rpm is Alaskan night and day. But LFP batteries minimize the O&M equation even further, especially when compared to a lead-acid battery bank.
“Going back to ‘why this took so long,’” Kennedy says, “I think what we’re seeing is this convergence of various technologies that are all maturing to finally create a sweet spot where projects like this aren’t just possible but feasible and actually work.”
Arctic circular economy
Every 12.8 kWh of stored solar energy is a direct replacement for a gallon of diesel. This microgrid has been functioning for about a full year now, resulting in 15,360 gal of diesel fuel the Shungnak community no longer needed.
That’s 166 tons of CO2.
That’s a cost savings in the range of $125,000 to $135,000 for the year — savings that go directly back to the community itself as an independent power producer that will be banked to further build out more renewable energy projects to, one day, turn those diesels off for good.
Next up, Northwest Arctic Borough is seeking to install more PV + batteries to get closer to 35 percent of the area’s needs while also looking into wind and ultimately connecting another village to the mix, pending funding for the intertie and another solar array.
“There’s also a hyrdo project sitting in the background of all this,” Mathiasson says. “If it all ties together, we could get an even higher penetration of renewables. We have 11 communities in total. We’re aiming to get a project like this in all of them within five years.”