Modern buildings contain a lot of devices -- fans, pumps, lights, motors -- that can slow down or speed up, dim or brighten, or otherwise alter their electricity consumption on the fly. Utilities and grid operators are eager for fast-responding energy assets that can shave power usage within minutes or alter second-by-second consumption to help keep the grid humming at the right frequency.
But getting a world of indoor devices to interact with grid commands is a tricky matter, requiring all kinds of expensive integration work. Last week, Schneider Electric and partner IPKeys announced that they’ve successfully tested a new way of doing it, using the internet, a Wal-Mart Supercenter in Pennsylvania, and the OpenADR standard for automated demand response.
Under a Department of Energy project, the partners worked with mid-Atlantic grid operator PJM to turn its specialized synchronous reserve messages, usually sent via dedicated lines, into OpenADR web services messages that Wal-Mart’s building management system could turn into fast-responding energy control.
Schneider also used its variable frequency drive (VFD) lab in Raleigh, North Carolina to test IPKeys’ ability to translate PJM’s 4-second frequency regulation commands into OpenADR 2.0b messages. Variable-speed fans and pumps are able to slow down or speed up in increments without losing efficiency, making them able to respond to grid regulation needs.
In both cases, Schneider and IPKeys were able to take communications using DNP3 or ICCP, two standard utility protocols, and translate them into web services, for simple dissemination over the internet. That’s an important step in showing that these specialized grid operator commands could use the internet for some or part of their task and reach all the systems and devices that are connected to it.
Meanwhile, turning 4-second signals into commands for variable-speed fans and pumps to follow opens up new potential for frequency regulation -- the task of moving power generation or consumption up or down in small increments to keep grid frequency in balance. That service is mainly provided by power plants today, but new federal regulations are providing financial incentives for faster-reacting resources, like grid-scale batteries, to fill in some of that market.
At the same time, demand-side resources like heating and cooling can also be moved up and down in four-second increments – and so can flexibility in moving air and water, Mark Feasel, Schneider’s vice president of smart grid, said in an interview this week.
“You’re selling flexibility, is all you’re doing, and it’s up or down,” he said. “True frequency response is the ability to follow the signal.” VFDs have that kind of capability to slow down for awhile, and then speed up for awhile, as long as they stay within minimum thresholds for handling the air or water they’re moving around the building. (This ecosystem of intelligent distributed demand will be one of the topics at Greentech Media's Grid Edge Live conference June 24-25 in San Diego.)
The project with Wal-Mart has been going on for almost two years now, and the partners have put a lot of effort into baselining the facility for minute-by-minute energy use, then figuring out how much flexibility is available for grid services, he said.
Translating energy market signals into OpenADR messages “happens both in the cloud, which we’ve already done, and in the building, where we’ve specifically designed our system to work with existing technologies,” he said. “It is designed to look like a generator that’s sitting there in spinning reserve, that’s on-line and turning but not connected to the grid. It gives the assurance that this capability is there in real time.”
That’s a step better than the typical demand response program, which involves giving day-ahead or hours-ahead warning to facilities to turn down energy use, he added. Traditional demand response also calls for longer periods of reduced energy use, with the commensurate impacts on operations in the buildings taking part. Synchronous reserves call for shorter periods of change, usually less than 10 minutes, and frequency regulation happens fifteen times per minute.
Schneider and IPKeys are far from alone on exploring the cutting edge of fast-acting demand response -- giants including Honeywell, Siemens, General Electric and Johnson Controls are working on similar capabilities. Startups in the field include Demansys, Enbala Networks and Viridity Energy in the U.S., and in Europe, REstore, Kiwi Power, and Entelios (bought by U.S. demand response company EnerNOC earlier this year).
Schneider and IPKeys have only now announced results from their pilot projects, but Feasel said the partners are looking at ways to bring this kind of functionality to commercial scale. “We’ve got utility demand response and energy information software, and have the proper connectors there to the DR world,” he said. Schneider Electric is also a big maker of VFDs, inverters and similar power equipment, and “we’re exploring options in our inverters and other devices to build in this kind of functionality” to respond to grid signals, he said.