Distributed Energy Resources

Ames Electric, with Iowa State University, is hosting a ‘mobile microgrid’

Ames Electric Services in Iowa is providing support for a mobile microgrid project initiated by the Iowa National Guard.

The mobile microgrid comprises solar panels with a total capacity of about 15 kilowatts (kW) and six Tesla Powerwall lithium-ion batteries with a combined capacity of 60 kW, 78 kilowatt hours, all packed into a 20-foot shipping container.

The “microgrid in a case” can be readily shipped anywhere via truck or train or ship, unpacked and set up and be ready for service in two hours, Donald Kom, electric services director at Ames Electric, said. The equipment can generate single phase or three phase power at either 110 volts or 220 volts.

The mobile microgrid also includes a 6.5 kW diesel generator in case “all else fails,” Kom said, and Ames Electric Services 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 and its partners, SunCrate and PowerFilm Solar for the Iowa Army National Guard.

Funding came from the National Guard and the Iowa Economic Development Authority.

The National Guard was interested in finding a way to have power at remote locations.

Even though the mobile microgrid was designed for uses such as emergency outages, in its current location it can be used by the public to charge electric vehicles. It is sited and in operation on a utility lot at the end of Main St. in Ames.

Kom said 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 otherwise it is bad for the batteries,” Kom said. The mobile microgrid will provide a valuable test site for the performance and operation of the equipment and will also provide visibility for the microgrid and the renewable energy technology. “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 things we are trying to do is see how long the batteries last,” Kom said. “We are going to load it up as much as we can. We are going to put it through its paces.” The mobile microgrid is expected to stay on its current site for six to nine months. 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 of the unit.

Kom said he also sees a potential benefit for the utility having a mobile microgrid. In August, Ames Electric was hit by a derecho that left some customers without power for up to a week. It would have been “a huge benefit” to have a mobile unit that could have provided power for 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, Kom said.

Separately, Ames Electric is preparing to go live with its first community solar project just before Christmas. Ames Electric is selling shares – what it calls Power Packs – in the 2.2 megawatt (MW) solar farm to its customers. Each share requires a $300 one-time investment and represents 175 watts of capacity.

Share owners will receive monthly credits on their utility bill, expected to be about $1 per month, based on the electrical output of the solar farm. Ames estimates customers could earn back their investment in 16 or 18 years, depending on how much the sun shines. About one-third of the shares will likely go to Iowa State University. Ames Electric would use the solar output not taken up by share owners to feed into its grid.

Ames Electric is also a recipient of an award stemming from a settlement with Volkswagen and is using the money to install at least two level-three electric vehicle chargers on Interstate 35.