Electricity markets serving the eastern United States bent but did not break yesterday in the face of some near-historic low temperatures and record levels of power demand.
Not unexpectedly, power prices soared, driven by natural gas prices spurred higher by demand for both space heating and electricity generation.
But as of press time, extreme measures such as targeted power curtailments or rolling blackouts had not occurred because of a successful level of cooperation among the region's four independent system operators: the PJM Interconnection, Midcontinent Independent System Operator, New York Independent System Operator and ISO New England.
The so-called polar vortex that forced temperatures to well below freezing starting Monday as far as the Gulf Coast was expected to boomerang in the next 24 hours and return the eastern United States to seasonable cold temperatures by tomorrow. The fleeting yet extensive nature of the vortex differs from typical winter cold snaps that tend to be longer-lasting and limited to a smaller geographic area.
As a result, the Energy information Administration issued a rare Energy Market Alert yesterday, reporting that in New England, all pipelines from the west and south into the New England region were constrained and that flows on the marginal pipeline into New York City (Texas Eastern-Tetco) also were constrained at key points.
Critical notices were declared yesterday on the Algonquin and Tetco pipelines, which were requiring hourly scheduling from electricity generators, EIA said. And Spectra Energy was considering an operational flow order for its Algonquin pipeline, restricting unscheduled service as necessary.
Even though the pipelines that serve New England from the west operated at near-full capacity, "New England has not experienced any serious gas availability issues that have had an impact on power grid reliability," said ISO New England spokeswoman Ellen Foley.
The reasons include increased imports of liquefied natural gas from Canada that relieved some constraints and "the increased use of the fuels other than natural gas, oil and coal to help maintain the reliability of the system," Foley explained.
Moreover, the ISO at noon yesterday implemented its "master local control center procedure No. 2" -- grid operator jargon that signals to transmission and generation owners that there are "abnormal" market conditions and they should "halt any kind of routine maintenance on their resources so that we could have as many available resources as we could in the event we have to assist our neighboring regions throughout this peak period," Foley said.
"We're in good shape," she noted, pointing to expected peak demand of 20,860 megawatts yesterday. The winter peak of 21,514 MW was set Dec. 17.
A key reason is that "New England has taken measures to make sure that all of the oil-fired generators have oil available and in their tanks," said Scott Niemann, a director with Energy Security Analysis Inc.
"They issued [a request for proposals] last year to secure those resources to make sure that they would be paid to cover all of their cost. Anybody who owns oil-fired generation in New England is doing very well over the last few days because prices have been high, they've got the oil in the tanks, and they're running and collecting their payments," he said.
The polar vortex is so widespread that "a lot of the things that the ISO has been able to rely upon in the past -- leaning on their neighbors and things like that -- just hasn't really been available," Niemann said.
Voluntary conservation in N.Y.; peak power record in Midwest
That neighbor-helping-neighbor ethic was on display by the NYISO yesterday as it called for the statewide activation of voluntary demand response programs -- in which consumers reduce usage -- between 4 and 10 p.m. The NYISO said in a statement that it made the call to "support electric system reliability throughout the Northeast and Midwest regions as frigid weather conditions impact electricity use and power production."
The NYISO also encouraged consumers to conserve electricity by adjusting thermostats, refraining from using major electric appliances, and turning off unnecessary electric lights and appliances from 4 to 10 p.m.
"The Northeast, mid-Atlantic and Midwest regions are under significant stress, and we continue to work closely with system operators in all of our neighboring control areas to coordinate resources and support system reliability throughout the region," said NYISO President and CEO Stephen Whitley.
The NYISO anticipated peak demand could rise to near-record levels for a winter day. The previous record winter peak demand of 25,541 MW was set Dec. 20, 2004.
In the Midwest, MISO issued a statement saying the severe weather conditions "have had a significant impact on the supply and demand of electricity. The combination of elevated demand levels and power plants being forced offline create tight operating conditions, the effects of which include elevated wholesale power prices." MISO credited its wholesale market operations with enabling grid reliability and allowing it to provide emergency assistance to neighboring ISOs.
MISO set an all-time winter peak Monday of about 109,300 MW. A Cold Weather Alert for the north, central and parts of the south regions of MISO through 10 p.m. yesterday signaled to the market that MISO might have to defer or cancel planned outages to meet supply needs.
Mechanical problems for PJM
PJM was expecting an all-time winter peak demand for 140,000 MW of power yesterday across its footprint, which includes 13 states and the District of Columbia, said Michael Kormos, executive vice president of operations (Greenwire, Jan. 7).
The previous record of about 136,000 MW was set during the winter of 2007. PJM's summer peak demand, in comparison, is about 165,000 MW.
Kormos said freezing temperatures forced an unspecified number of generators offline due to operational challenges related to the cold -- including interruptions in gas supplies -- and more may shut down. But Kormos could not provide information about specific plants or locations of those units, adding that such information will be gathered once the emergency situation passes.
"It's been everything, from just mechanical problems potentially due to the cold weather to just normal generators" failing, he said. "Particularly when we push them as hard as we've been pushing them, we have tube leaks and normal breakage, we have had some fuel interruption on the natural gas system."
PJM asked generators Monday to ramp up to maximum emergency outputs and temporarily reduced voltage on power lines by 5 percent across its system and called on up to 5,00 MW of demand response yesterday. It also asked its 61 million customers to conserve power by postponing major electrical appliance use and turning down thermostats.
PJM also bought emergency power from the New York system and the Midwest and has been supplying emergency power to the Southeast, Kormos said. "This particular cold is far-reaching, and most of our neighbors are experiencing the extreme conditions that we are, as well," he said.
Going into yesterday evening's peak, PJM spokeswoman Paula Dupont-Kidd said "we are seeing about 36,600 MW of forced generation outages, or about 20 percent of our installed capacity."