What does a demand meter measure?

A demand meter specifically measures the maximum amount of power used by a consumer during a designated time period, typically expressed in kilowatts (kW). This measurement is crucial for utilities as it helps them assess peak demand and make informed decisions regarding capacity planning and resource allocation.

Understanding this concept is essential because it highlights the difference between total energy consumption and the rate of energy usage at peak times. While total energy usage, which could be measured by an energy meter, is important for billing purposes, demand measurements directly relate to the instantaneous power needs of a consumer. This allows utility companies to manage their supply effectively, ensuring they can meet high usage demands without risking overloads on the electrical grid.

The other choices relate to different electrical measurements and concepts. For example, total energy used over a month is indicative of overall consumption, and average power used throughout the day does not provide the peak demand needed for operational management. Furthermore, a voltage drop in electrical circuits relates to electrical engineering and circuit performance rather than the specific measurement of demand as defined by a demand meter.