On a crowded stretch of one of the Twin Cities’ busiest freeways, a glassy new five-story building announces itself with a large sign saying, “OATI Microgrid.”
Inside the building in Bloomington, workers are putting the final touches on the OATI Microgrid Technology Center, which features solar panels, wind turbines, a combined heat and power plant and energy storage.
It’s part of a pilot project for Open Access Technology International, a Minneapolis-based company that provides cloud-based software applications for more than 1,600 clients, including independent service operators (ISOs), electric cooperatives, energy traders and utilities.
“We could have developed this site as a backup power generator, but instead we’re going a step further and building it as a microgrid site, fully islandable from the grid,” said David Heim, OATI’s chief strategy officer.
“We’re building it to be able to demonstrate how a microgrid can not only make sense in terms of providing backup power for a critical facility, like our data center, but also can make economic sense.”
Having OATI’s logo and the word “microgrid” attached to the building is certainly a marketing ploy, even if some of the commuting public on the I-494 corridor near the region’s international airport and Mall of America has no idea what the word means.
“We are a software technology company, a data center company and we serve utilities, so we built this building as a showcase, as a demonstration of microgrid technology and our GridMind software,” Heim said.
GridMind is a sophisticated system that manages power distribution by taking into account energy production, weather, energy pricing and dozens of other variables. Imagine the software as a conductor managing an orchestra of energy sources.
The building will remain connected to Xcel Energy’s grid, Heim said, while leveraging power from its different energy sources. When the cost of energy from the electric grid increases during, say, warm summer days, the software may shift to draw down stored power and solar energy. Should Xcel’s grid ever fail, the microgrid could power the building and those in the surrounding neighborhood “for almost as long as we want to,” Heim said.
In a crisis situation, GridMind can reduce temperatures on floors by two degrees, tap into the battery storage or draw more power from the CHP, he said.
Having the microgrid makes even more sense considering OATI will be using part of the building as a data center. Data centers need to have a strong backup power system in case of outages, he said.
OATI’s data center also showcases an integrated approach to microgrid development. The companies providing hardware for the OATI microgrid are “alliance partners” and are part of the company’s pitch, said Terry Mohn, executive consultant with OATI.
Vendors were carefully selected for the microgrid, and the software was optimized to work with their products. By using this approach, OATI and its partners can “replicate an installation over and over again,” Mohn said. “You don’t have unique integration costs every time.”
Unique arrangement

Showing off the rooftop on an overcast day, Heim pointed to an elevated structure where 150 kilowatts of solar panels would soon be installed. Eight vertical axis Aeolos turbines will be placed on the back end of the roof. Large metal containers will hold an Ensync 125 kW battery that will store electricity from the turbines and solar panels.
Six floors down in the basement, the scene is entirely different. Huge color-coded pipes create a byzantine network of connections, tying together a 600 kW Capstone natural-gas-burning microturbine paired with absorption chiller and heat exchanger. Energy storage technology will occupy part of the basement, too.
To an outsider, the ground level looks like the industrial vision of an M.C. Escher print, with pipes and large machines creating an intriguing, if confusing, visual landscape.
The variety of energy inputs — and the fact that it resides in one building — makes for a unique arrangement, Heim said.
“I don’t think there is anything as elaborate as this, to my knowledge,” Heim said. “There’s nothing as advanced, control-wise, as this building anywhere in the country.”
GTM Research’s Ben Kellison, director of grid research, said a microgrid in one building is unique. Many buildings have backup generation that draw from multiple sources, but they don’t function as working microgrids until there’s an emergency. Also, most microgrids serve the military (42 percent) or campuses (30 percent), according to GTM’s research.
“Most are multi-building sites,” Kellison said. “There aren’t a ton of single-building microgrids that we see around.”
Microgrids represent a small slice of the energy market, albeit a growing one. GTM recently adjusted its forecast for 2020, increasing microgrid penetration from 2.8 gigawatts to 3.7 GW by 2020, Kellison said.
‘Big fish in a small pond’
The company made its mark by serving ISOs and being “the big fish in a small pond,” said Kellison. As the company moves into other areas of power management, the competition will be stiffer.
With more than 1,600 customers and nearly 1,000 employees, Mohn explained the company’s advantage comes from its well-established presence in key energy sectors.
OATI is not a venture capital startup, but rather a 20-year veteran of grid management development, with more than 95 hardware and software products, he said.
The GridMind software has not been implemented outside of the OATI microgrid campus yet, though that will change early next year, Mohn said. The company sees huge potential in big-box merchants because they own many single buildings and have big energy needs, he said.
Data centers may be another market. A well-managed microgrid could shave 20 to 30 percent off energy costs for a building or a campus, he said. Part of that is due to the sheer sophistication of software, which is sure to be a key to energy management in the future.
The company also says Xcel has been a good partner on the project, which will be important as microgrids become more common, Heim said.
“The future is being able to have a tighter interplay between microgrids, distributed energy resources (DERs) and utilities,” he said. “We want to be able to allow the utility to see microgrids and DERs as a beneficial resource as opposed to something on the grid they’re competing with, or thinking of it as a problem.”