Electric submetering is an equitable way to allocate the cost of a building's electricity among its tenants. Studies show that such separate metering also encourages tenants to reduce their energy usage (relative to no metering). But what happens when a building is changed to a single tenancy? In one building, conversion of apartments into offices for personnel all working for the same firm (and thus not receiving individual electric bills) found that going back to a master meter was a good investment.
Most small commercial electrical accounts (e.g., less than about 10 kW) are billed only on consumption. Electromechanical meters used to measure such usage do not separately measure demand. When utilities develop load projections for service classes lacking demand metering, they statistically sample customer usage patterns to determine typical demands based on usage patterns. Fixed costs (such as to build and replace power plants, transmission lines, etc.) are then allocated among customers through that demand calculation. For a large group of customers, such a methodology generally results in a fair estimate. But for a subgroup that may have differing usage characteristics (e.g., seasonal, major night usage), an assumed demand based solely on consumption could end up overcharging for that demand component.