At a natural gas storage facility in Tilden, field operators put bolts in place as they seal a panel after they finish up maintenance on a compressor.
The compressor, one of four at the Tilden facility, is a key part of the operation: it will help move natural gas from the storage field to Ameren Illinois customers in the metro-east as temperatures begin to drop.
“When we need to pressurize the gas to get it out, then we start running the compressors to get the pressure up to get it through the system,” said Steve Underwood, director of gas storage for Ameren Illinois.
The work is part of the winter heating preparations.
In order to help keep natural gas prices low during the winter time for customers, Ameren Illinois buys its supply during the summer months when supply prices are low.
Ameren Illinois customers who receive natural gas supply through the utility are set to pay 44 cents per therm this winter.
An average Ameren Illinois residential customer using 745 therms per year could expect to pay $719 a year based on the current 44-cent forecasted price, the utility said.
Ameren Illinois sells natural gas to its customers at the same cost the utility pays for it.
“We buy during the summer, when prices are low, and store in the fields. That way we could buy it cheap. That way we could help reduce the price for customers,” said Kelly Hendrickson, a company spokeswoman.
Ameren will buy 70 percent of its natural gas from companies such as Exxon Mobile or from producers in Oklahoma and Texas, during the summer.
The remainder is purchased week to week. Sometimes gas is purchased a few years ahead of time to protect against volatility, Underwood said.
Buying natural gas ahead of time means it has to be stored in fields such as the one in Tilden, where there is a sandstone cavity 800 feet below the surface of the storage field a mile long and half a mile wide.
The cavity can hold 850 million cubic feet of natural gas, and the facility has the ability to withdraw 50 million cubic feet of natural gas on really cold days for up to 50,000 residential customers, Underwood said.
Ameren Illinois has to make sure it keeps enough natural gas stocked through Jan. 20, which has traditionally been the coldest day, and is when the utility statistically has peak usage. The utility then has to cycle out its natural gas during the rest of the season, said J.R. Jennings, superintendent of storage fields for Ameren.
“You want to keep the elasticity of the field,” Jennings said. “It’s good for the field to cycle the gas.”
While at the storage field, when natural gas is being prepped to be moved to transmission pipelines, the gas has to go through a series of pipes and fans to dry out the gas.
Underwood said when the gas is deposited into the fields during the summer, it’s dry, but when it’s in the reservoir, it picks up a lot of moisture.
As temperatures began to drop last week, contractors added insulation to large vessels and did some work on water and drain lines as part of final preparations.
The vessels, which are used to help dry the natural gas, sometimes reach temperatures of 400 degrees, meaning the foil insulation wrapped in fiberglass is needed for safety, said Kyle Turner, a supervisor of storage fields for Ameren.
Winter prep work also takes place even when outside temperatures are hot.
During the summer months, workers repainted equipment and upgraded parts of the system to improve reliability, including installing new valves, new piping and rebuilding control valves, Turner said.
Throughout the Ameren system, the utility modernized its delivery infrastructure, such as replacing old pipelines at the end of its useful life.
“Reliability is a huge factor for us, especially in the winter when customers expect that natural gas to be there every day,” Underwood said.
Ways to reduce your heating bills during the winter
- Keep your thermostat at 68 degrees or lower. You save about 3 percent on your heating costs for each degree you lower your thermostat.
- Use a programmable thermostat to automatically adjust the temperature of your home according to your family’s schedule. Have lower temperatures when you’re sleeping or away and higher temperatures only when needed.
- Set your water heater to 120 degrees for safety and energy savings. Lowering the setting of your water heater thermostat can save approximately 3 to 5 percent in energy costs.
- Only heat the rooms you need to heat by closing vents and doors to unused rooms.
- Adequately insulate your home, which can reduce energy usage by up to 30 percent.
- Keep drapes and furniture from blocking air vents.
- Use weather stripping and caulk to reduce air leaks.
- Use ceiling fans to move warm air away from the ceiling to the floor, by running fans at a low speed in a clockwise direction (as you look up at it).
Source: Ameren Illinois