Weather is fickle. We have cold winters and mild winters, hot summers and hotter summers.

But consumers should be able to count on the rates they are charged to heat or cool their homes — or at least to understand why those rates change.

SCE&G customers haven’t really had that option for three years, and it’s time they do.

The S.C. Office of Regulatory Staff, at the request of the state Public Service Commission, recently completed an investigation of SCE&G’s Electric Weather Normalization Adjustment (eWNA), designed to minimize the impact of extreme fluctuations in weather, both on customers and SCE&G. It concluded that the eWNA program was so opaque that it should “be terminated with the last billing cycle for December 2013.”

In short, the ORS found that customers have no way of verifying the program’s effects on their bills.

The ORS reports that from August 2010 through August 2013, more than 21,000 different factors were applied to customers’ bills. No wonder 189 customers contacted ORS with questions and concerns about eWNA.

SCE&G says it changes rates according to the weather. When summer temperatures are cooler than usual, rates are increased to protect SCE&G from a drop in revenue. Conversely, when summer temperatures are unseasonably warm, rates are decreased to protect the customer. SCE&G says customers have saved millions of dollars because of eWNA, but ORS says the opposite could also occur.

ORS is concerned that the program could be deterring customers from conserving energy. Without knowing how rates fluctuate, there’s no price incentive to conserve.

The ORS also takes issue with SCE&G imposing the eWNA on customers who use natural gas (not electricity) to heat their homes. That is in addition to a gas weather normalization adjustment. It sounds like a double whammy.

Public utilities are expected to provide electricity and natural gas at stable, predictable rates that the public can understand and accept. This program falls far short of that goal.

The Public Service Commission should demand that SCE&G address the criticisms and demonstrate how eWNA is saving its residential customers “millions.”