By Tom Kleckner
AUSTIN, Texas — ERCOT members last week voted down the ISO’s attempt to salvage a revision request that would have replaced several ancillary services with four new products.
The nodal protocol revision request (NPRR), rejected earlier in the month by the Protocol Revision Subcommittee, was shot down again when the Technical Advisory Committee upheld the subcommittee vote by a 23-3 margin Thursday.
NPRR 667 would have improved regulation service and replaced non-spinning reserve and responsive reserve service with a combination of four new services: fast-frequency response, primary frequency response, contingency reserve and supplemental reserve.
However, staff was unable to convince stakeholders the revisions were ready for prime time. Speaking for the subcommittee, Luminant’s Amanda Frazier said ERCOT did not demonstrate a current or future reliability need for the services and did not adequately address their costs and funding.
“What I heard from PRS members is [ERCOT has] exceptional performance from a reliability perspective,” said Frazier, the subcommittee’s chair. “It has consistently improved over time, so even though we’ve seen growth of intermittent resources over the last decade — exponential growth — we also see performance that is improving.”
Frazier said stakeholders also had concerns over market liquidity for the new services and would prefer to see ERCOT focused on identifying reliability needs and alternatives to NPRR 667. “ERCOT has expressed a preference for a vote on 667 before examining alternatives,” Frazier said. (See “NOGGR Tabled, Other Revision Requests Approved,” ERCOT Technical Advisory Committee Briefs.)
“ERCOT doesn’t do this very often,” said Dan Woodfin, the ISO’s director of system planning, of the appeal by staff. “I can’t recall [something like] this in my 13 to 14 years here.”
Woodfin based his case to the TAC on ERCOT’s changing resource mix since the ancillary service framework was built. Whereas ERCOT was 75% reliant on coal- and gas-steam energy in the late 1990s, half the current resource mix comes from gas turbines, combined cycles and renewables.
He said the current bundled framework will keep more expensive generation online, extend negative price periods and curtail less expensive resources, resulting in increased ancillary service prices and higher overall costs — especially with an increase in high-wind, low-load periods.
Ancillary service “was designed around the characteristics of those steam boilers,” he said. “We have a whole lot of new resources … that has changed both the needs and the ability of different resources to provide those services. We’re expecting the resource mix to continue to change. We’re seeing some pretty tremendous changes on wind in the system … solar is growing exponentially.
“[ERCOT’s current] ancillary service requirements … provide a barrier to entry to new types of resources that don’t have inherent characteristics of the old steam boilers.”
Woodfin pointed to The Brattle Group’s recent report on the ERCOT market, which he said found the ancillary service proposal to be a good, cost-effective market design. (See Brattle Study Sees ERCOT Continuing to Rely on Nat Gas, Renewables.)
“We don’t want to maintain barriers of entry for any technology,” said Frazier in questioning the benefit of ERCOT’s proposed changes. “It seems expensive to invest millions of dollars for new technology that would only bring in 200 MW.”
Frazier said several market participants (MPs) believed ERCOT’s estimated impact analysis of $12 million to $15 million was too low. She also acknowledged “the good work done in the last several years to think through the future resource mix.”
“We think there are also many MPs that believe there are incremental changes that can be made to the ancillary service suite that can deliver the value Dan mentioned,” Frazier said.
ERCOT was unfazed by losing its appeal of NPRR 667, which was first filed in November 2014 after a year of stakeholder discussions. Spokesperson Robbie Searcy said the ISO will continue its work with stakeholders to plan for future ancillary service needs.
“ERCOT continues to believe the concepts set forth in” the NPRR, she said. “As grid characteristics evolve, it is important that we are planning ahead to ensure we have appropriate market tools in place to maintain system frequency and overall reliability.”