Rumor is True. Oncor Unveils First-of-a-Kind Microgrid

April 7, 2015
Rumors have circulated for months that S&C Electric, Schneider Electric and Oncor had in the works a microgrid more sophisticated than any so far built in North America. Here it is.

Rumors have circulated for months that S&C Electric, Schneider Electric and Oncor had in the works a microgrid more sophisticated than any so far built in North America. Today the companies lifted the veil off the completed project near Lancaster, Texas.

The new microgrid isn’t particularly large (1.25 MW), but oh what’s inside. Not one microgrid exactly, but four working together (or apart), offering a first-of-a kind automation that hints at the distributed grid to come.

Industry visionaries describe a future U.S. grid where multiple microgrids can act in concert. With little or no human interaction, these microgrids of the future puzzle out a complicated dispatch of power and storage that they can share. The goal is to achieve highest reliability at lowest price and integrate renewable energy.

The Oncor microgrid steps the industry toward that future.

The four microgrids, or zones, include nine generation sources: two solar photovoltaic arrays, a microturbine, two energy storage units and four generators — operated by one microgrid controller suite.

The microgrids can operate independently, together, or as one through a distribution automation scheme that leverages intelligent grid products from S&C Electric and Schneider Electric.

“You have four different microgrids at the site that can be optimized separately. Each one of the zones has either a distributed energy source in it, or an energy storage unit. We physically can control each one of them independently,” said David Chiesa, S&C Electric’s director of microgrid business development.

Further, the microgrid controller suite and distribution automation switches allow the system to actually sectionalize. The project can allocate generation from one microgrid to the other microgrids, as needed. This is done automatically with no human interaction.

Features that together make the Oncor system unique among microgrids
  1. Designed as a microgrid from the beginning (many of today’s microgrids evolve out of existing infrastructure)
  2. Offers autonomous high speed dispatch with load preservation control (no manual intervention)
  3. Also offers automonous economic optimization (looking at prices 15 minutes ahead, an hour ahead, and a day ahead)
  4. Can sectionalize and operate independent zones as individual microgrids
  5. Ten managed resources (the utility plus nine distributed generation resources) interwoven to serve a relatively small load, 1.25 MW

The microgrid not only automates dispatch, but also pricing signals, determining when it’s best to buy, sell or store power, again without manual intervention. “That’s another huge leap forward in terms of microgrids.” Chiesa said.  The Schneider microgrid controller allows the system to look at prices 15 minutes, an hour, and a day ahead, and also take into account weather forecasts.

The project also is rich with “inverter-based resources” and notable for its use of battery energy storage as an anchor resource — the resource it follows when it separates from the grid, said Philip Barton, Schneider Electric’s microgrid program director.

Sources of Generation in Oncor Microgrid: 65-kW microturbine; 210-kW diesel generator; (2) 175-kW diesel generators; 45-kW reciprocating natural gas generator; 25-kW community energy storage; 106-kW carport PV array; 8-kW ground-mounted solar; 200-kW stationary battery storage; capability to add future wind generation

With this project, Oncor is challenging the idea that utilities cannot innovate. The Texas utility is already  notable for putting forward the idea of  integrating 5,000 MW of battery storage into the Texas grid. Now it’s created a highly sophisticated microgrid — and did so within just nine months,  Chiesa said.

“Oncor is investing in this microgrid to better understand how microgrids and distributed energy resources can make the grid better,” Barton added. “Not only are they looking at the technical aspect of this, but the economic and regulatory side.”

Chiesa noted that just two years ago microgrids were not seen as a utility play, in fact were perceived as a utility threat in some cases.  “Now we’ve seen the tide turn. Over the last year we’ve seen a flood into microgrids from utilities. I only see it continuing in 2015.”

Oncor plans to offer the project as a learning lab for the industry, and has created a demonstration and visualization room at Oncor’s System Operating Services Facility in Texas. It is opening the project for tours, offered by both S&C Electric and Schneider Electric.

A video about the Oncor project is available here.

Below are more details about the Oncor project from a news release issued this morning by S&C Electric and Schneider

During a loss-of-power event, a combination of S&C’s advanced distribution automation equipment and Schneider Electric’s Microgrid Controller (MGC) use high-speed communications and distributed grid intelligence to automatically detect a problem on the grid. It starts with S&C’s IntelliRupter PulseCloser fault interrupter which detects an interruption in  power, tests to see if the issue is temporary or permanent, and if it is permanent dynamically islands the facility. The system then uses S&C’s Scada-Mate CX Switches and Vista Underground Distribution Switchgear to automatically re-configure the distribution system while the MGC autonomously switches to alternative distributed power sources. “It does all of this in a matter of seconds, or faster than a customer could find their flashlight in the dark,” says Chiesa.

The energy storage systems are the backbone of the microgrid, which include S&C’s PureWave Community Energy Storage System. The onsite energy storage—which stores energy from either the utility feed or any of the facility’s  generation sources—provides the voltage signal for the site, enables renewable integration, controls the microgrid frequency and is the first generating source to respond during an unexpected loss of power.

The microgrid system also benefits from advanced grid technologies developed by Schneider Electric, including the PowerLogic load preservation system, the microgrid controller and a new technology called StruxureWare Demand Side Operations (DSO). Schneider Electric’s DSO model delivers economic optimization and dispatch of the microgrid distributed energy resources (DER), allowing the system to maximize renewable energy usage and storage while minimizing energy costs. DSO’s innovative platform makes this possible by leveraging market pricing signals, weather and forecasting information, historical energy usage data and real-time building information.

“Working with Oncor and S&C to demonstrate how DSO cost effectively brings grid scale dispatch and optimization technology to the microgrid is exciting,” says Philip Barton, Microgrid Program Director of Schneider Electric. “By combining S&C’s solutions with Schneider Electric’s PowerLogic load preservation system, microgrid controller and DSO, I am confident that Oncor’s system is one of the most advanced and comprehensive microgrids in the market today.”

To help educate and demonstrate the benefits of microgrids to residents, students, policymakers and businesses, S&C and Schneider Electric were asked to develop a microgrid demonstration facility on the SOSF campus. That facility will be known as Oncor’s Technology Demonstration and Education Center (TDEC) and consists of two exhibits – an immersion room and a demonstration center. In the immersion room, the Oncor microgrid story is brought to life on seven screens for a full cinematic experience. The microgrid story highlights the history of the electric grid and the changes Oncor has made over time.

“Oncor has a rich history of working collaboratively with its vendor partners and this is a great opportunity to showcase those relationships in a state-of-the-art microgrid facility,” says Michael Quinn, Oncor Chief Technology Officer.

The Center, which also serves as the SOSF microgrid control center, displays the new technology that Oncor is using on their system. The demonstration room features a fully functioning SCADA representation of the microgrid to show how the system reacts to a loss of power event such as extreme weather. Once an event is created, the switching devices respond accordingly, clearing the fault, isolating the faulted section and restoring service from an alternate source. The switching devices, controls, communications and software shown are all real and completely functional.

S&C and Schneider Electric will be demonstrating the system for the first time to attendees of the Third National Microgrids Conference, being held in Dallas April 14-16, 2015. Subsequent tours of Oncor’s microgrid can be arranged by e-mailing [email protected].

To get a free copy of the Oncor Case study visit Schneider Electric’ Microgrid resource library.

About the Author

Elisa Wood | Editor-in-Chief

Elisa Wood is the editor and founder of She is co-founder and former editor of Microgrid Knowledge.

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