Duke Energy, the giant U.S. utility that’s been pushing for interoperability standards for the smart grid industry, has now put its weight behind an emerging standard for connecting grid-scale energystorage

On Wednesday, Duke announced it is joining the MESA Standards Alliance, a group that’s developing non-proprietary communications specifications for grid-connected batteries. Over the coming months, Duke will be joining the alliance’s technical committees, with an eye on helping to guide what’s emerging as a common way to get grid batteries communicating with utility control systems.

Consider it the latest example of how the energy storage industry is moving from a one-off, pilot project model to commercial scale. Mandates in states like California, New York and Hawaii, and market opportunities at grid operators like PJM, are helping to bring hundreds of megawatts of storage projects onto the grid in the coming years.

GTM Research predicts the U.S. will deploy 220 megawatts of energy storage in 2015, with the market on a path to reach 861 megawatts of annual installations and a value of $1.5 billion in 2019, about 11 times its 2014 size.

That’s pushing utilities and project developers alike to come to agreement on a core set of technologies to use from project to project. While companies such as Greensmith, Younicos, AES Energy Storage, Geli, Stem and Green Charge Networks are building software to manage batteries from utility scale to behind-the-meter, there are very few non-proprietary options available, Thomas Golden, Duke technology development manager, said in an interview.

“We went out into the marketplace to see what standards are out there, and there wasn’t really anything beyond MESA,” he said. “What we get out of this is an opportunity to influence the standard we think will push the industry to the next level.”

The MESA (Modular Energy Storage Architecture) alliance was formed last year, with a list of members that include core software developer 1Energy, inverter maker Parker Hannifin, flow battery startup UniEnergy Technologies, big French grid player Alstom, and the Department of Energy’s Pacific Northwest National Laboratory.

Since then, it’s added big battery vendors like LG Chem and NEC Energy Solutions as members, and continued to work on its integration with the SunSpec Alliance, the solar inverter makers communications standards group.

MESA is also the technology being used to connect energy storage systems being deployed by Washington state utilities Snohomish PUD, Avista and Puget Sound Energy, a nod to the standard’s Pacific Northwest roots. Two big municipal utilities, Austin Energy in Texas and Sacramento Municipal Utility District in California, have since joined the alliance as well.

But Duke is by far the biggest utility to join MESA so far. The Charlotte, N.C.-based multi-state utility is responsible for roughly 15 percent of the country’s utility storage projects, including one of the biggest, a 32-megawatt installation at its Notrees wind farm in Texas.

“There are tons of different vendors responsible for making batteries, communications technologies, inverters,” Golden said. “When you have that many people involved in an industry, in the beginning, it's OK to have projects where you engineer specifically for that project.”

But “if you don’t have standards associated with how you’re going to build it, that’s just one more thing you have to add to that list of things to do -- and everything you add to that list adds costs,” he said. “As energy storage matures, what you need, what the industry needs, is more standardization, to allow vendors to spend more time reducing costs, improving safety and reliability, and all those things our customers want.”

Duke has also taken a lead in pushing interoperability standards for the grid industry, via its Coalition of the Willing. Over the past three years, Duke has grown the list of participating grid equipment, communications and software vendors from six to 25, and led the creation of a new standard, known as Open Field Message Bus, or OpenFMB, that’s now being tested in DOE labs and utility pilot projects around the country.

Stuart Laval, Duke’s technology development manager who’s leading the utility’s OpenFMB work, is also joining the MESA alliance’s working groups to help guide development in a way that can ensure they’re aligned in the future, Golden said.

Duke coalition member Parker Hannifin is also a founding MESA member, and the alliance is also involved in the Duke-funded Battery Innovation Center in Indiana, Darcy Wheeles, MESA alliance program director, noted. By year’s end, the group hopes to have a draft release of its MESA ESS standard, which lays out a standardized approach to integrating batteries, inverters, software control systems, and the interface that communicates all that data to the outside world, she said. 

Using MESA standards doesn't preclude using software from other vendors for battery management, controlling aggregated storage systems, or linking their operations to grid needs and market imperatives, she noted. 

"There is a spectrum of software, from standalone companies or from energy storage developers," she said. "Some of them see standardization as important. Some of them see that standardization coming out as part of their own proprietary work." The MESA alliance sees its work as "allowing each company to elaborate, and do their value-add, and build off of a common base."