Ames Electric Services, a municipal electric utility based in Ames, Iowa, has teamed up with Iowa State University, also located in Ames, to provide support for a mobile microgrid project sought by the Iowa Army National Guard.
The mobile microgrid is composed of solar panels with a total capacity of about 15 kilowatts (kW), as well as six Tesla Powerwall lithium-ion batteries with a combined capacity of 60 kW and 78 kilowatt-hours. The solar panels and batteries are installed in a 20-foot shipping container.
The special mobile microgrid can be quickly and easily shipped anywhere in the state by truck, train or ship, unpacked, set up and ready for service within two hours, according to Donald Kom, director of electric services at Ames Electric. The specialized unit can generate single-phase or three-phase power at either 110V or 220V.
The mobile microgrid also includes a 6.5-kW diesel generator in case “all else fails,” Kom said. Furthermore, as an additional backup option, Ames Electric is also looking at adding a small wind turbine to the equipment.
The project was developed by the Electric Power Research Center (EPRC) at Iowa State University, as well as its partners, SunCrate in Sioux City, Iowa, and PowerFilm Solar in Ames. Funding for the project came from the Iowa Army National Guard and the Iowa Economic Development Authority, Des Moines, Iowa.
Even though the mobile microgrid was designed primarily for uses such as emergency outages, it can be used by the public to charge electric vehicles at its current location, which is on one of the utility’s lots in Ames. Kom said that Ames Electric intends to add an electric vehicle charger to the box and begin offering electricity to EV owners.
“We want to use it as much as possible,” Kom said. “Otherwise it is bad for the batteries.”
The mobile microgrid provides a valuable test site for the performance and operation of the equipment and will also provide visibility for microgrid and renewable energy technologies.
“We are hoping that the public will come and check it out and plug stuff in,” Kom said. “This is a win-win for the both the project creators and the public. The site offers great visibility and opportunity for public education.”
One of the current goals of the project is to see how long the batteries will last.
“We are going to load it up as much as we can,” Kom said. “We are going to put it through its paces.”
The mobile microgrid is expected to stay at its current location for six to nine months. During that time, Ames Electric intends to collect data from the unit and share it with the EPRC, which can use it to make improvements and produce a second-generation unit.
Kom said he also sees a potential benefit for the utility having a mobile microgrid. In August 2020, Ames Electric was hit by a derecho (an “inland hurricane”) that left some customers without power for up to a week. According to Kom, having had the microgrid available at the time would have been a huge benefit by providing power to customers to charge cell phones and other essential equipment, as well as providing a focal point from which the utility could disseminate information for customers.