When temperatures plunged below freezing last week, North Charleston resident Doris Washington learned just what a difference was made by the energy efficiency work completed in her home earlier in January.

The upgrades were made at no cost to Washington by the Sustainability Institute and a program the nonprofit group runs that trains at-risk youth in efficiency-related home repairs. Washington's home was the 100th one in Charleston and North Charleston to be upgraded through the Energy Conservation Corps initiative.

Washington, a disabled 59-year-old who previously worked as a truck driver, cosmetologist and seamstress, said she was paying around $300 a month to heat or cool her modest, 950-square-foot house.

"For this size house, that seems like a lot," she said. "Normally we had to raise (the thermostat) up to about 85 to get the house warm."

The Energy Conservation Corps did an energy assessment of her home, and was able to reduce air leaks by 60 percent, while adding insulation and reducing leaks in the duct work, according to the Sustainability Institute.

"They pretty much sealed up every hole and everything they could find," said Washington. "I'm grateful for that, and hoping to see a decrease in my electric bill."

"When you're on a fixed income, everything's a blessing," she said.

The Sustainability Institute says the homeowners who have received help are now collectively saving $70,000 yearly on power bills, while the Energy Conservation Corps also trained area youth - young men, mostly - for the workforce.

"We're real proud of how it's shaped up," said Sustainability Institute Executive Director Bryan Cordell. "We have 100 percent job placement for the youths that have gone through the program."

The program has been in place since 2010, operating with funding through the federal Americorps program, plus grants from local governments and donations from businesses including Boeing, Cordell said.

To date, 43 at-risk youth enrolled in the program and received classroom and on-the-job training, and 24 graduated.

"They only reason more didn't graduate is, some got hired before they graduated," said Cordell.

"It's a real range of work they are doing," he said. "Insulation and contracting companies will come in and hire them."

The participating youths are typically recruited through church and neighborhood groups. They are typically from low-income neighborhoods, and most of those who graduated from the program had been previously "court-involved" according to Cordell.

Washington said the crew that worked on her house did a good job and explained everything they were doing.

"I don't think a lot of people realize (the program) existed," she said. "And, there are a lot of people who need that sort of help."

Washington said she learned about the program after contacting her North Charleston councilwoman, Dot Williams, looking for help with home repairs. A series of medical problems has kept Washington from working recently.

"Disability threw me out of a job, and I would love to work," she said.

The free energy efficiency upgrades are available to lower-income homeowners, who can apply through the Sustainability Institute's website, sustainabilityinstitutesc.org, or get an application by calling 843-747-5885. For homeowners who can afford to pay, the Sustainability Institute offers energy efficiency testing, information about tax incentives and rebates, and help finding contractors through its CharlestonWISE program.

For Washington, the Energy Conservation Corps program has already made a difference in her comfort.

She said she no longer needs to use an electric blanket to stay warm in her previously drafty bedroom.

"A matter of fact, a few nights I took the covers off of me," Washington said.

And when the next electricity bill arrives, she should see the financial benefits of having a more energy-efficient home.

Reach David Slade at 937-5552