Metering Systems

A variety of metering systems are currently on the market for Federal facility implementation. The information below outlines common metering system capabilities and common metering system components.

Metering System Capabilities

The capabilities and functionality of metering systems vary depending on the individual metering system. The following are some of the more common features used by Federal facilities:

  • Data Recording: Advanced meters can record total energy resource consumption in addition to enhanced functions like time-of-use, peak demand, load survey, and power outage. Electrical meters may also be able to record data points such as voltage, current, and power factor.

  • Total Consumption: The most basic data function, total consumption records kilowatt-hour (kWh) of electricity, hundred cubic feet volume (CCF) of natural gas, or gallons of water consumed between meter readings.

  • Time-of-Use Metering: Different rates can be charged for on-peak and off-peak time windows by recording when energy is consumed. Time windows typically vary by time of day and weekday/weekend/holiday.

  • Peak Demand Metering: Billing may be based on total energy consumption and the highest 15-, 30-, or 60-minute demand during the billing period. The peak demand may be reported as a single highest value, highest four values, or highest value during each hour (all peak demand values must be accompanied by an associated time stamp).

  • Load Survey: Energy consumption and conservation impact studies require detailed demand data. A load survey provides periodic consumption or demand data in time increments ranging from one to 60 minutes.

  • Monitoring and Control: Two-way communication between a central station and facility site provides the opportunity to integrate other utility functions into the metering system. Meters can be programmed to detect and report when a fault or power outage is detected as well as leak and tamper detection. The meter can also dispatch control functions, such as remote service disconnect/reconnect, demand-side management (DSM) load control, and load scheduling.

  • Load Control: Load control includes DSM control functions like air-conditioner and water heater load-shedding. This function is important for many energy incentive programs. The DSM load control could be triggered by a fixed algorithm or real-time central station control.

  • Load Scheduling: Load scheduling includes scheduled equipment starts and stops to minimize or shift load to take advantage of demand and time-of-use billing rate structures.

  • Leak Detection: Continuous monitoring of gas or water usage/pressure can be used to detect leaks.

Metering System Components

While individual technologies and capabilities vary, the necessary system-level components for Federal implementation stay relatively the same from one unit to another. Viable building-level metering systems contain the following four necessary components:

  • Meters: Meters span two broad application categories – electrical and flow-related.

    • Electrical meters can track whole-building energy use (e.g., utility meters), sub-panel energy use (e.g., lighting), or a specific end use (e.g., an individual motor or chiller).

    • Water, steam, natural gas, and other flow-related meters are typically in-line installations using positive displacement, insertion turbine, or pressure-related techniques. Depending on the application, these meters vary in size, type, output configuration, accuracy, and price.

    All meters provide some output related to resource use across energy, water, natural gas, etc. Features and functionality increases with meter sophistication. Electrical demand tracking, power quality measurements, and multiple-meter communication are examples of functionality commonly found on more sophisticated meters.

  • Data Collection: Data collection and automated meter reading (AMR) systems collect and report resource usage data through the central system. This component depends on facility communication systems to report resource use.

    It is important to consider what existing communication networks are available while planning data collection systems (e.g., building automation system, local area network, etc.). Leveraging existing networks lowers the final cost and complexity of the project. It is often beneficial to leverage multiple networks (e.g., IP, phone, etc.) to gain necessary coverage and redundancy.

  • Data Storage: Data storage and retrieval must be carefully considered during the design and implementation of metering systems. A clear understanding of data needs and applications is the primary driver of storage decisions.

    Database systems and storage capacity typically provide the foundation for data storage. Both are tied closely to data use. Long-term measurement requires more data to be collected, analyzed, and stored while short-term measurement requires less.

    Federal agencies can choose to either host data storage on-site or work through an application service provider. The decision, as well as the overall data storage and retrieval component, should be decided with assistance from agency IT staff.

  • Data Analysis: Manually analyzing metered data can be time consuming and difficult. Most meters now include off-the-shelf software applications as part of the overall system. In addition to manufacturer offerings, third-party software vendors also develop and offer custom software applications for data analysis. A third option is hiring an outside data analysis service, which ranges from simple use-reporting and tenant billing to sophisticated energy diagnostics and system performance indicators.