Integrating – not just adding distributed energy resources – is the key to strengthening the new grid. That realization is what led to the Duke Energy microgrid test bed, created with the help of an intriguingly named ‘Coalition of the Willing.’
The impetus for the project goes back to a few years ago, when the utility saw the explosive growth in distributed energy resources — especially in Hawaii and California.
“We saw there would be issues if we didn’t have a plan to interconnect the resources and fully integrate them on the grid,” said Jason Handley, Duke’s director of smart grid emerging technology and operations.
So Duke began the ‘Coalition of the Willing’ – willing because only six companies* initially agreed to sign on when they discovered what the venture would entail. They were being asked to leave behind their secrets and openly share their knowledge, products and expertise.
The project aims to ensure distributed resources can work together. Microgrids play a critical role in making this happen.
“Instead of having one-off solar installations or battery installations, if we can group these together, we can enhance the overall grid,” said Handley.
Duke Energy microgrid test bed – a first
Duke Energy’s microgrid test bed in Gaston County, North Carolina represents one of the first inter-operable microgrids in the country. It addresses problems created by the fact that most microgrids use only one vendor’s equipment. Ideally, the microgrids should be able to use different vendors’ equipment.
“Microgrids are technical to put together,” said Handley. “Generally you use one vendor’s equipment. But you may have to replace that equipment with other equipment.”
In addition, Duke would like to be able to use its own infrastructure to connect to microgrids and distributed resources.
“We have a lot of installed equipment on our grid already that we don’t plan on changing. What we’re trying to figure out is how to use that equipment in microgrids today,” he said.
In this effort, it’s critical that the different resources and equipment can communicate with one another.
For example, if devices on the grid can communicate with each other to fix high- or low-voltage problems without sending an alert to a control center miles away, they can reduce what was a five-minute process down to less than 10 seconds, and provide better operation, as well.
“The main thing you need for microgrids is a strong communication backbone,” Handley said. If the resources are going to work together, it’s critical to coordinate them quickly.
“We need to move data between them to make decisions. For the microgrid we’re installing at our test facility, we’re working in a coalition with 25 other vendors and trying to take the vendors we use today and make their equipment able to talk to other pieces of equipment that are not the same brand,” Handley explained.
The company has partnered with utilities, research labs, government agencies and vendors to create what’s called the “Open Field Message Bus,” a standards-based system that aims to reduce the complexity and cut the costs of integrating distributed resources. Funding for the project has come from Duke and through equipment donations from vendors.
The OpenFMBTM has formally been adopted by two task forces within the Smart Grid Interoperability Panel and the North American Energy Standards Board, according to company materials.
“It’s really a reference architecture and framework for allowing intelligent distribution modes at the end of the grid to interact with one another,” he said. He defined this as equipment that is on distribution lines close to customers at the edge, where power lines stop, he explained.
Future of microgrids
Ultimately, Duke wants to use microgrids to be active participants in the grid. “We want to control and optimize the generation resources around us. To do that, we need fast communications and we believe you need to have a large communication pipeline at the edge; that’s the Open Fields Message Bus.”
Duke may even provide financing for microgrids to help achieve its goal.
“We may need to finance them for customers as well as install and operate them,” Handley said. “Other companies are trying to install them for customers, but Duke believes there could be a business case to do this on our own. We have good access to capital and know how to operate a grid better than anyone else. It’s potentially a win-win and fully takes advantage of distributed energy resources coming on line.”
Called Mount Holly, the microgrid test bed incorporates a number of different resources, including a 100-kW PV solar system; a 250-kW battery energy storage system, a 10-kW solar carport with EV charging abilities and automated distribution grid equipment, including smart meters and sensors.
The growing success of Duke’s effort is capturing industry attention. More than 25 vendors are now working on the project and others are joining. From a handful of ‘willing’, the coalition grows and the industry learns.
*Echelon, S&C Electric, Alstom Grid, Verizon, Ambient Corporation and Accenture. Duke Energy
Let’s hear about other microgrid test beds underway. Post descriptions below or on our LinkedIn Group, Microgrid Knowledge.