BGE's NEW deferral plan (not to be confused with the July 06-May 07 deferral plan) will not keep track of what each individual household defers and must pay back. What that means is you might end up paying back slightly fewer or more dollars than you deferred.

Instead of creating a separate deferral account for thousands of households, BGE will simply track the debts/credits in aggregate. For the deferral phase of the plan, they'll give credits per kilowatt-hour calculated to make charges to deferring households 18 percent lower and then 8 percent lower than the market rate. Then they'll apply a repayment charge for 21 months to recoup the deferred amount, without interest. For the average household, it'll be a wash. You'll pay back what you deferred. But if you use substantially more electricity during the payback period than you used during the deferral period, you'll end up paying BGE more than you deferred. This is because the deferrals/repayments are unchanging quantities tied to kwh, and BGE is assuming that most people will use roughly the same amount of juice in both cycles. But if you're planning to add central air or a swimming pool next year, you'll probably end up repaying more than you deferred.

BGE's description of its plan is HERE.