The coldest weather in more than a decade proved too much Tuesday for SCE&G generating plants knocked out by mechanical failure attributed to the deep freeze.
As temperatures plunged, demand peaked and generating capacity fell at several power plants.
The most significant malfunction happened at the 605-megawatt Williams Stations near Goose Creek, which is the second-largest fossil fuel-fired plant in the SCE&G system.
"The bitter cold temperatures affected normal operation of a transmitter involved with regulating pressure in the plant's boiler system," SCE&G spokesman Eric Boomhower said in an email.
Other plants affected by the weather included Urquhart Station, Fairfield Pumped Storage, Wateree Station and McMeekin Station.
SCE&G said it would take steps to prevent a recurrence of the outages that affected 50,000 statewide, including 9,000 in Charleston County.
The preventive measures include portable heaters to reduce the effect of extreme cold on equipment, he said.
Boomhower said what happened Tuesday to the generating plants was not predictable.
"As you might imagine, power plants are very complex facilities featuring an abundance of moving parts and electronic components," he said. "We simply could not have anticipated the specific issues that arose in this particular situation."
Joan Hoyte, 69, of Summerville, said that she initially had power, but she lost it later in the morning when the company implemented rolling blackouts in her area. Hoyte expressed frustration at SCE&G's reasoning for outages.
"What if we had a hurricane? What if we had an ice storm or a wind storm? All that happened was the temperature went down and they couldn't handle it," Hoyte said. "With the amount of money you pay and all the rate increases, that shouldn't even be an issue. They should be prepared for any emergency."
The high temperature Tuesday was 33 degrees at both Charleston International Airport and the U.S. Customhouse in Charleston. Wednesday morning lows were forecast to be 18 degrees for the airport and 28 for the city, the National Weather Service reported.
SCE&G on Tuesday morning ordered rolling blackouts because of peak demand for electricity and lost generating capacity. The 15-minute power losses affected different areas at different times.
The outage hit about 9 a.m. at Page's Okra Grill in Mount Pleasant during breakfast, which is the most profitable time of day, said co-owner Courtney Page.
"We lost a lot of money," she said.
She was going to send staff home for the day when the power returned at about 11 a.m.
Page was without power at her Dunes West home starting at 7 a.m. She got the kids ready for school in the dark.
The Charleston County Sheriff's Office on Tuesday opened its work camp at the Cannon Detention Center on Leeds Avenue to those needing overnight shelter. CARTA offered free bus service to the camp.
The Highway Patrol on Tuesday reported 618 requests statewide for motorist assistance during a 24-hour period, which was a three-fold increase over the same time last year. For local Troop 6, there were at least 95 calls for help, more than double last year.
Record lows Tuesday contributed to the widespread outages, National Weather Service meteorologist Vern Beaver said.
Temperatures were around 20 degrees on the peninsula Tuesday morning. Charleston International Airport reported lows near 17 degrees.
John Blitch of Blitch Plumbing said the company was inundated with calls from people who said they had no water. The cause was frozen pipes, he said.
Blitch said the company was running on a generator because the power at its offices was out.
The firm received about 100 calls by mid-morning, which is 20 to 30 times normal volume, he said.
When the pipes thaw, cracking and bursting will become a concern, he said.
Customers left cold water dripping to prevent pipes from freezing, but they did not leave hot water dripping. So the hot water pipes froze, he said.
Crisis Ministries was at capacity with 124 men, women and children. In addition, 14 more people were staying on cots in the soup kitchen area, said spokesman Amy Zeigler.
The usual check-out time from the shelter was being waived because of the cold, she said.
"It's going to be brutal today," she said.
About 2,400 of SCE&G customers without power were near North Charleston and West Ashley, an outage map showed. Another 300 reported outages near Mount Pleasant. About 500 customers were reportedly without power near James Island.
Traffic lights were reported out in Charleston at Meeting and Calhoun streets, Meeting and George streets, Meeting and Broad streets, King and George streets and St. Philip and George streets, police spokesman Charles Francis said.
On Wednesday, the high temperature is expected to be in the upper 40s, but wind will make it feel like 12 degrees in the morning, according to forecasters with the National Weather Service.
Temperatures are expected to rise into the 60s Thursday, with lows in the mid-40s, forecasters said. By Friday, the temperatures level a bit with lows in the 50s expected throughout the weekend.
Natalie Caula Hauff and Diette Courrégé Casey contributed to this story.