ERCOT’s latest resource adequacy forecasts project the Texas grid will have sufficient installed generating capacity this fall and winter, despite the destruction wrought by Hurricane Harvey.
Pete Warnken, ERCOT’s manager of resource adequacy, said staff studied several scenarios that could affect the availability of generating resources. The results were favorable.
“[We] do not currently anticipate any systemwide issues,” Warnken said in a statement Thursday. “Even in the most extreme scenarios considered, there were ample operating reserves.”
The fall seasonal assessment of resource adequacy (SARA) report shows nearly 86 GW of capacity available for a predicted peak demand of just over 56 GW. The final fall SARA, covering October and November, includes 3 GW of new generation added since the preliminary report in May.
Exelon accounted for 2.2 GW of the new generation, adding gas-fired combined cycle units at plants near Houston and Dallas. More than 837 MW of new wind and solar resources are expected to contribute 374 MW to covering the fall peak, based on capacity factors.
The preliminary winter SARA report projects a record peak of more than 61 GW, beating ERCOT’s all-time record of 59.7 GW, set in January. The report, covering December through February, anticipates almost 85 GW of capacity being available.
ERCOT will release the final winter SARA in early November.
Harvey Restoration Efforts Continue, but Numbers Down
ERCOT said last week that while Hurricane Harvey’s restoration efforts will continue for an “extended period” in some areas, the number of affected transmission facilities and generation resources has decreased considerably since the storm hit the Texas Gulf Coast on Aug. 25.
The ISO said Friday that one 345-kV line still remains out of service. However, the grid has remained stable and the competitive markets have continued to operate normally, it said.
Most of the remaining outages are in Rockport and Aransas Pass, where the storm’s eye made landfall. AEP Texas said 15,000 of its remaining 16,600 outages were in the Rockport-Aransas Pass area as of Friday afternoon. The utility said it may take an “extended amount of time” to reconnect power to some homes and businesses damaged by Harvey.
CenterPoint Energy said about 3,200 customers remained without power in the Houston area Friday afternoon. The utility has been forced to route power from a flooded distribution substation to a nearby temporary substation in west Houston.
Most of CenterPoint’s customers without service live near the overloaded Barker Reservoir. The U.S. Army Corp of Engineers has been releasing water to save the reservoir’s structural integrity.
Entergy reported about 2,300 customers out of service in Southeast Texas as of Friday afternoon.
Southern Cross Offers Suggestions for its Market Participation
Stakeholders on Thursday discussed potential definitions and market participant categories during a workshop for the Southern Cross Transmission Project, which could become ERCOT’s first merchant DC tie operator.
The ISO does not currently include DC tie operators as market participants, but the project’s developer is working to define language that would allow the proposed DC tie with the Eastern Interconnection to take part in the market. The HVDC transmission project would be capable of shipping more than 2 GW of electricity between the Texas grid and Southeastern markets.
“There’s a way to do this that would probably make sense,” Cratylus Advisors’ Mark Bruce said, speaking for Southern Cross Transmission (SCT). “We have a bunch of boxes that Southern Cross can’t check [on the market participant agreement form]. [The tie] doesn’t serve load, [and] it doesn’t buy or sell energy. ‘DC tie operator’ would describe the function we’re registering for. We think that’s a good place to start.”
The project would link ERCOT to the Eastern Interconnection through a 345-kV line, owned by Garland Power & Light, that connects with a convertor station just across the Louisiana border. SCT would build a 400-mile, 500-kV DC line to connect with Southern Co.’s existing 500-kV system in Alabama.
SCT envisions ERCOT qualified scheduling entities (QSEs) buying capacity on the line similar to how they do on the ISO’s existing five DC ties. The company would not participate in the settlement process, but the QSEs would. Southern Cross would not have a Texas tariff or collect transmission rates, leaving the QSEs responsible for paying transmission service charges for use of the ERCOT system.
“Users of the Southern Cross line are going to pay for this equipment in the capacity charge. ERCOT ratepayers aren’t going to be paying for any of this,” Bruce said.
He suggested protocol language for a DC tie operator as a market participant that “has completed applicable registration and approval for the purpose of operating a DC tie interconnected to the ERCOT transmission grid.” Bruce also drafted bylaw language for a definition of an independent DC tie operator, suggesting it be any transmission and distribution entity or affiliate that “owns or operates” a DC tie interconnected to ERCOT’s grid or is “preparing to own or operate” such a tie.
Bruce said SCT would fit best in ERCOT’s investor-owned utility segment. He pointed out the company is investor-owned and a “public utility” under the Federal Power Act, although not under Texas law. Its only function in ERCOT is operating a high-voltage transmission facility, he said.
ERCOT staff will now work with SCT to develop and submit the appropriate revision requests to the Protocol Revisions Subcommittee for its November meeting. Market participants were invited to provide feedback and input from the workshop, along with other comments for consideration prior to sponsoring the appropriate revision requests.
The Public Utility Commission of Texas opened a pair of dockets for the SCT proposal. Docket 45624 approved Garland P&L’s application for the 345-kV line, which has an established route. Project 46304 establishes the PUC’s 14 directives for integrating and operating the project as a part of the ERCOT system and within its market construct.
Southern Cross obtained final FERC 210/211 orders and agreements in 2014 for interconnection to and transmission service in ERCOT that maintain its FERC jurisdictional status quo.
Developers hope to begin construction in 2019 and commercial operation in the third quarter of 2022. They are working to obtain a siting certificate for the line’s Mississippi portion from the state’s Public Service Commission. Louisiana does not require a siting certificate.
— Tom Kleckner
