S&C Electric recently addressed a series of challenges to help provide microgrid engineering support for a project in Lancaster, Texas. Oncor, a Texas transmission and distribution service provider, partnered with S&C to provide engineering expertise, as well as new equipment to build and operate an advanced microgrid. Oncor wanted to showcase the latest advancements in energy storage and smart grid technology with the new Lancaster advanced microgrid.
Crews install S&C Vista Underground Distribution Switchgear. (Photo: S&C Electric)
Challenge
Oncor was looking to incorporate distributed generation sources ranging from a propane-fueled microturbine to photovoltaic (PV) solar arrays and battery energy storage.
The utility also wanted the new advanced microgrid to have manual and autonomous control capable of advanced functionality, including self-healing, islanding and load balancing.
Advanced Microgrid Solution
What approach did S&C present? After taking a look at its budget, the company decided to construct a mixed brownfield and greenfield microgrid. This project required “engineers to make a previously established electrical infrastructure and repurposed generation equipment function harmoniously with modern generation, switching, and protection equipment,” S&C explained.
Oncor initially was in the market for a greenfield microgrid, but to ensure the solution was consistent with Oncor’s budget, S&C proposed to construct a mixed brownfield and greenfield microgrid.
A colorized schematic view of the system’s four smaller microgrids. (Image: S&C Electric)
Beginning the project, S&C first worked to assess the site’s various distributed generation assets and evaluate how to achieve microgrid functionality. The microgrid required new generation sources, including PV solar arrays, a propane-fueled microturbine, and battery energy-storage systems.
To effectively use the existing diesel generators and avoid installing new generation sources for this mode, S&C’s design incorporated them by dividing the microgrid into four smaller microgrids, or operating zones.
With four separate zones, generation sources that could not be paralleled could operate independently. Additionally, the zones double as a method to effectively balance the generation sources with the load across campus.
The company also addressed issues related to the site’s existing electrical-protection scheme by installing eight protective relays on the Vista Switchgear.
With the new protective relays, the microgrid can appropriately protect itself regardless of whether the microgrid is grid-tied or islanded.
“In order to test 21st century grid innovation for its customers, Oncor partnered with S&C to deliver engineering expertise and state-of-the-art equipment to build and operate the most advanced microgrid in North America.” –Michael Quinn, vice president and CTO, Oncor
Result
S&C’s engineering team designed the Lancaster advanced microgrid around an existing electrical infrastructure and 30-year-old generation equipment.
Today, Oncor’s previously established electrical infrastructure and repurposed generation equipment functions harmoniously with modern generation, switching, and protection equipment.
This project illustrates the reality that microgrids are rarely constructed from a “blank canvas.” And often, many don’t have the budget to build a microgrid from the ground up.
Read more on the new Lancaster advanced microgrid.
