Time of Use Energy Metering (TOU)

Time-of-Use, or TOU as it is commonly referred to, is the segregation of energy rates based on the time in which the energy is being consumed. TOU is a way in which utility providers attempt to alleviate demand during peak periods by enforcing a tariff structure that charges an increased rate within the typical peak consumption time periods. 

TOU is broken into three structures or groupings with various names in reference to peak, off peak and the time of moderate use referred to as shoulder time or mid-peak. These TOU groupings can vary based on region and have become increasingly deployed in utility electricity charges.

Emergence of TOU

TOU has been implemented to change consumer behaviour and to ease the strain of energy usage required at its most in-demand time. This decreases the likelihood of power outages as well as over-generation of power supply. TOU has become an effective way for utilities provider to manage their power production, record energy consumption and allowing consumers to take control of their energy bills. This added control has led consumers to cut energy costs. By reviewing their energy consumption and making use of peak analysis tools, consumers applied load shedding by running machines at off-peak hours whenever possible.

TOU Implementation

Accuenergy has multiple metering models which allow customers and businesses to take control of their operational costs with the TOU functionality. In addition to its fundamental use (from a building management standpoint) the TOU is also an effective tool for landlord’s energy management strategy – to correctly align charges with tenants, saving money and rewarding efficient energy usage. Without the use of this TOU feature in environments that have time based tariffs, tenants can dispute charges on the grounds that incorrect tariff rates are being applied. TOU features can be found in the Acuvim-EL, the Acuvim IIE and the AcuRev 2000 series power meters which cover a variety of different metering applications.
Acuvim KL Economy submeter
Acuvim EL Multi-function Time of Use Power Meter

The Acuvim-EL meter is a multifunction power meter equipped with TOU for single and three phase circuits. The Acuvim-EL features a Modbus RS485 serial connection in which the meter can connect to the Acuview free data logging software to take advantage of this feature. While connected to the software the meter is able to segregate up to 4 different tariffs, 12 seasons and 14 schedules.

This option is a cost-effective solution for users monitoring a single circuit that are able to connect the meter to a dedicated computer and are typically featured in smaller applications where TOU billing has been implemented.

Acuvim II Series for Advanced AC Monitoring in vehicle charging stations
Acuvim IIE Time of Use Power & Energy Meter

The Acuvim IIE is an intelligent multifunction power meter with TOU enabled for single and three phase circuits. The Acuvim IIE meter features Modbus RS485 communication standard and can be upgraded to include Modbus TCP Ethernet, BACnet, Profibus, and a variety of other communication protocols and I/O expansions for added versatility. The meter can be serially connected to a computer hosting the free Acuview software or can be remotely connected to the computer utilizing an Ethernet connection. In addition to the proprietary software the Acuvim IIE also has the means to connect to any third party software or server that is able to take advantage of the meters innate TOU functionality.

As this meter has remote metering capabilities multiple units are able to be connected to the same central computer or system allowing for utilization in larger projects with multiple users such as residential or commercial buildings or for a more granular look at machines and devices in order to take control of operating costs, generate cost allocation, and determine if load shedding is required.

AcuRev 2000 Multi-Circuit Power & Energy Meter

The AcuRev 2000 series meters are multi-circuit power and energy meters capable of reading up to 18 single phase circuits or 6 three phase or single phase three line circuits in one compact meter. This multi-circuit metering line is the preferred choice for dense or branch circuit metering applications. Both the 2010 and 2020 models come with TOU as an innate function; the 2010 measures basic energy and demand, while the 2020 measures power, energy and demand as well as power quality parameters and other advanced metering parameters.

The meter features Modbus RS485 communication standard and also has the option to upgrade to the remote metering compatible Ethernet communication allowing for multiple meters to be monitored by one central computer and a greater application freedom. The meter offers the same application benefits as the Acuvim IIE but is specially designed for large branch circuit or dense circuit metering where multiple tenants or metering points can be derived from a single panel.

Application Summary

These three TOU enabled meters can be used to manage single point, medium sized projects, and large branch circuit monitoring applications in which a TOU tariff structure is in place to effectively take control of consumption charges and effectively manage time-based energy usage. TOU enabled meters are necessary in applications in which there are time-based tariff rates to properly align charges with usage, these TOU meters can also be used to reduce costs by reviewing machines and devices cost allocation and making use of tools and practices such as load shedding and running machines at off-peak hours.