Mysterious charge has many SCE&G customers crying foul - wistv.com - Columbia, South Carolina |

Essentially, it increases or decreases the price you're paying per kilowatt hour, based on a 15- year average of temperatures.  It's not just the weather. Other factors go in.  SCE&G breaks it down into 19 different WNA categories, based on your billing rate, house type, and the usage response to weather conditions.  Then they factor in the month, the billing cycle, and heating degree days and cooling degree days. 

"They may dispute this," said C. Dukes Scott with the Office of Regulatory Staff. "But I don't think there's but one person over there that understands it fully and that's the man who designed it."