Precise, economical timing devices now make it possible to provide highly accurate revenue metering technology at the customer level, providing potential savings.
Realizing Savings
Eager to improve overall system utilization, utilities offer certain customers incentives to use power at off-peak hours by providing them with lower energy rates during these periods. While this seems simple enough, the amounts of money can be considerable, and a meter with a simple real-time clock that slowly drifts off (until it is reset) probably will not be acceptable as a basis for determining billing periods.
Today, the cost to provide accurate time, directly traceable to national standards, is quite reasonable. It is practical to provide an accurate clock right at the customer premises, connected directly to (or part of) the revenue meter.
Accuracy
Keeping accurate time is necessary for this application since fair performance of contract requirements requires the utility (and customer, if applicable) to apply the correct rates for the proper intervals of time. Often, these incentives are coupled with the customer’s efforts to move load to off-peak periods.
The accuracy required ranges from a fraction of a second, for basic billing considerations, to perhaps as little as a millisecond where the clock is used to synchronize periodic measurements of power-quality quantities such as harmonics and flicker. Different measurement intervals will yield different results, possibly leading to conflict between utility and customer.
