The Organization of MISO States continues to signal its grid operator that regulators are ready for dynamic transmission line ratings in the footprint.
OMS invited an ERCOT executive to explain the benefits of dynamic line ratings (DLRs) at its board of directors meeting Thursday.
ERCOT Senior Director of System Planning Warren Lasher said DLRs provide value, “especially in off-peak conditions like spring and fall, when you’re likely to see more wind on the system.”
The Texas grid operator now uses dynamic ratings in 60 to 70% of its circuits, Lasher said. He said it uses data lookup tables from transmission owners coupled with local weather data to assign ratings.
“We’ve seen a significant amount of benefits, in two ways really. … We’ve seen reduced congestion, and we’re able to get more lost cost power to our customers. But we also see in our reliability studies that we can schedule more maintenance outages in the spring and fall,” Lasher told regulators.
OMS has recently been in discussions with MISO Independent Market Monitor David Patton about implementing DLRs. OMS President and Minnesota Public Utilities Commissioner Matt Schuerger said in June that the RTO’s ratings are overly conservative, inconsistent and not transparently formed.
MISO TOs have also been meeting with Monitor staff to discuss dynamic and ambient temperature-adjusted line ratings, Otter Tail Power’s Stacie Hebert said last month.
The Monitor made implementing DLRs one of five new recommendations late last month in its annual State of the Market report. (See IMM Issues 5 Recs in MISO State of the Market Report.)
During this month’s Market Subcommittee meeting, Patton said the annual value of MISO’s real-time congestion routinely exceeds $1 billion, due in part to “very conservative, static ratings by most transmission operators.”
“I think more are becoming aware of this problem,” Patton said, citing last year’s FERC technical conference and OMS’ interest.
Patton said a “broad adoption” of ambient-adjusted ratings could have reduced congestion costs by as much as $150 million in 2018 and 2019. Over those two same years, had TOs just provided short-term emergency ratings, an additional $114 million could have been saved in congestion, he said.
However, Patton said he’s had little luck so far trying to convince individual TOs to use the technology.
OMS Executive Director Marcus Hawkins said the group will present a position statement in August on the subject. He said he believes MISO’s systems are advanced enough to accommodate the technology.
