DDDC - What it Means
You've probably noticed the line marked DDDC on your natural gas bill. This represents the Dedicated Design Day Capacity charge.
The DDDC charge, determined by Atlanta Gas Light Company, is included in your AGLC base charge. DDDC is based on the delivery costs for each customer's demand to the gas pipeline system on the coldest day of the year.
"Walton EMC Natural Gas has no control over DDDC charges," says Allen Powers, Director of Walton EMC Natural Gas. "We can't make any adjustments. They're given to us directly from Atlanta Gas Light."
If the coldest day of the year is in December, AGLC considers your peak usage for that month to recalculate your DDDC for the next year.
DDDC is recalculated and approved by the Georgia Public Service Commission annually. AGLC also factors in specific information like your home's gas appliances and past usage patterns.
If you used more natural gas in the same month AGLC experienced its peak usage, the increased consumption will figure into the new DDDC calculation.
Living in a new home? Since new construction has no past usage patterns, AGLC calculates DDDC charges based on the home's gas heated square footage and its natural gas appliances.
DDDC varies month to month following AGLC's seasonal rate plan. According to the plan, customer's DDDC charges are higher during the winter months and lower in the summer. This follows the customer's traditional usage patterns - more natural gas usage during the winter and less in the summer. It also results in higher AGLC base charges in the winter and lower charges in the summer months.