The Federal Energy Regulatory Commission yesterday (Oct. 19) moved to make the conversion from direct current based renewable generation seamlessly integrated into the alternating current electric transmission grid. FERC’s new rule, according to an agency news release, “directs the North American Electric Reliability Corporation (NERC) to develop a suite of new or modified reliability standards that comprehensively address IBR data sharing, model validation, planning and operational studies, and performance requirements.”
NERC must come up with three sequential filings to implement the rule, each “due no later than November 4 of each of the next three years. NERC also has 90 days to submit to the Commission an informational filing that includes a detailed, comprehensive standards development and implementation plan.”
Matching DC with AC, using inverters and related equipment, is a needed and until recently underappreciated, technology to accommodate the rise of solar photovoltaics, wind power, fuel cells, and battery storage. Increasing use of HVDC transmission also requires inverter-based technologies.
In May, 2021 near Odessa, Texas, a combined-cycle gas-fired generating plant tripped off line, due to what a reliability expert described as “a small, ordinary line-to-ground fault.” The result was entirely unexpected: solar photovoltaic generation over a 200-mile section of the Electric Reliability Council of Texas grid also went offline. The fault tripped the inverter moving the solar DC to the grid’s AC. The event is now known as the “Odessa Disturbance.” The issues had also come up in 2016 in California when a fire damaged several transmission lines, tripping some 1,200 MW of solar capacity.
Inverter-based resources (IBRs), FERC said, “use power electronic devices to change the direct current power produced by generators into alternating current power that is then transmitted on the bulk electric system. In certain cases, these resources respond to grid disturbances differently from traditional generation resources such as hydropower, nuclear, coal or natural gas plants. Most mandatory reliability standards were developed for traditional generation resources, so today’s final rule is important to ensure IBRs support reliability in the same manner as traditional generation resources.”
FERC Chairman Willie Phillips said, “These standards will help us solve one the biggest problems we’re facing, as we make the transition to clean energy resources. We need to make sure that these promising new technologies can enhance, not weaken, reliability of the grid. We mean it when we say that at FERC, reliability is, and remains, Job No. 1.”
Commissioner Allison Clements said, “Inverter based resources provide an exciting opportunity for dynamic response and for increased operational flexibility.” She added, “I also hope that NERC will mandate data sharing requirements from transmission owners to the IBR generation owners and vice versa in its standards development process.”
–Kennedy Maize
To subscribe to The Quad Report – it’s free — use the email and type “subscribe” in the subject line.