PSE&G New Jersey is swapping out 1980s-era Westinghouse Type OD-4 meters with new Aclara smart meters on industrial accounts. Got curious about accuracy differences and had both meters tested at the same facility for two weeks before the old one was pulled. Results were interesting: the Westinghouse was reading 0.8% high, the Aclara is reading 1.2% high. Both well within ANSI standards, but the net effect is about 0.4% increase in registered consumption. Over a year, that's $1,100 additional cost for this particular client. Not huge, but multiply across thousands of accounts and PSE&G is looking at nice revenue bump just from "technology upgrades."
Old Westinghouse meters vs new Aclara - accuracy comparison
Gloria, that's a smart approach doing the parallel testing. Most people never think to compare old vs new meter accuracy before the swap. Black Hills Energy out here replaced a bunch of 1990s GE I-70S meters last year with Sensus units. Didn't do parallel testing, but I noticed several clients had small but consistent increases in kWh consumption with no operational changes. Nothing dramatic enough to complain about, but your 0.4% increase theory makes sense. Death by a thousand small cuts.
This is why I always request meter accuracy certificates for both removed and installed meters during any swap. Xcel Energy Colorado usually provides them if you ask specifically. Most of the mechanical meters I've seen tested are actually reading slightly low after 15-20 years of service, while the new smart meters tend to read slightly high when first installed. The cumulative effect across a utility's customer base probably adds up to millions in additional revenue annually. Legal? Yes. Ethical? That's debatable.