Energy management is a growing practice among companies that operate large buildings, campuses, and other complex facilities. Sub-metering is sometimes an afterthought or left out of the equation but can bring great benefits and value to optimise energy and help drive carbon neutrality. Successful energy and carbon management requires detailed information on how they are being utilised. However, this valuable information is not always available in facilities and main meters alone.
In order for this to be effective, facility engineers need to understand exactly how and where their energy is being consumed within their properties.
Energy efficiency is the first step in achieving sustainability in buildings, helping to control increasing energy costs while reducing the environmental footprint. An energy management system (EMS) or building automation system (BAS) can also provide metering and sub-metering monitoring functions that allow facility managers to gather data and help them to make more informed decisions about energy use.
Electrical sub-metering involves the installation of either MID (Measuring Instruments Directive) approved or any meter capable of producing an output, such as pulse or Modbus that can measure energy usage after it reaches the primary utility meter.
Sub-metering offers the ability to monitor energy usage for individual tenants, departments, pieces of equipment or other loads to account for their actual energy usage.
One of the easiest ways to lose control of electricity costs is by what utilities refer to as “peak demand” charges. In this situation, a utility provider will charge a greater cost per kWh when demand is greater in order to prevent all consumers from maximum consumption during these peak times. The utility company argues that the grid must be able to support each customer’s maximum consumption, therefore the grid must be built to support each customer getting charged based on their maximum kW rate.
By increasing the cost per kWh, consumers will shift their usage to off-peak and reduce the chance that the grid reaches dangerous capacity levels. Sub-meters allow the end-user to receive detailed consumption information, which allows the customer to avoid cost increases with time-of-usage billing and to take advantage of off-peak rates.
In non-sub-metered commercial and residential buildings, tenants would typically be billed on square footage of rented space. In this scenario, the property owner receives an electrical bill for the entire facility and bills each tenant based on the amount of space they rent. The problem here is that tenants are not billed based on consumption behaviour, but rather they are billed based on the total consumption of the rest of the tenants.
Tenant sub-metering allows each tenant to be billed only for the energy consumed within the rented space. Revenue-grade and MID approved meters are accurate enough to be used for billing purposes and can be installed at each tenant location. By holding tenants responsible for their personal consumption, they will be more likely to reduce their electricity usage habits and lower the building’s overall electricity consumption.
When rising energy costs and a greater emphasis on energy efficiency, all types of facilities are looking to better understand their consumption and what is driving increased electrical bills. Sub-metering gives the user the ability to monitor individual pieces of equipment so that energy costs can be allocated to different departments and processes. By using this data, building managers have a better understanding of who is using the most energy and where it’s being used so corrective actions may take place.