BESS Addition - Power Plant Facility

22,000 batteries in 86 enclosures

Troubleshooting HVAC controls issue

System integration & commissioning of a real time data collection system

Project Description

Casne Engineering provided commissioning support for a 260 MW/260 MWh battery energy storage project in Granbury, Texas. This is the largest storage project of its kind in Texas. The energy storage facility comprises more than 22,000 batteries in 86 enclosures. This BESS facility can store enough electricity to power around 130,000 Texan homes in normal grid conditions. The batteries capture excess electricity from the grid, primarily overnight during high wind-output hours, and can release the power when demand is highest. This BESS system is a one-hour battery system with dispatchable, reliable generation providing operation and resiliency of the grid. 

In preparation for construction, Casne compiled comprehensive testing documents and commissioning procedures. This included a minimum performance testing procedure for individual BESS containers, which covered battery management systems, inverter power transfer for charging/discharging, safety systems, and HVAC. Sitewide functional testing covered requirements for Automatic Voltage Regulation (AVR) and Power Factor Regulation (PFR) within the Guaranteed Performance Level (GPL) limits. Casne coordinated directly with the Electric Reliability Council of Texas (ERCOT) to gather prerequisite studies and documentation and confirm the interconnect requirements. 

The fast-paced design-build project delivery approach was based on a number of vendor provided systems with multi-faceted interfacing between each system. Casne helped to navigate scope boundaries and communicate and troubleshoot a variety of issues between the various vendors. An example was when the switchgear/control room container had an HVAC controls issue. After monitoring HVAC parameters, we found evidence that two of the HVAC controllers were drawing excessive current, and this was affecting the UPS. Resolution involved coordinating with the HVAC vendor to update the control parameters. Another challenge encountered was the container UPS tripping and not resetting, which affected the BESS controller. Casne reviewed the schematics and found that a GFCI was feeding the UPS, which conflicted with the manufacturer installation guidelines. To resolve the issue an additional breaker was installed to separate circuits. Other challenges included a high voltage breaker that had to be replaced; and facilitating with networking to provide remote access for vendors and the owner. 

As a separate effort, Casne also provided system integration and commissioning of a real time data collection system. This allowed the system owner to gather critical monitoring data from all arrays, as well as battery warranty data. This consisted of 1-second-interval data for tens of thousands of points aggregated to a centralized historian. To ensure system robustness, the data load was distributed over a highly performant and redundant multi-server configuration. This data is used by the central power monitoring team to enable near-real-time monitoring and long-term analytics for troubleshooting and preventative maintenance.