Successful Energy Management
Through Electrical Submetering
What is Electrical Submetering?
Many commercial and residential buildings use a single "master meter." Electricity comes into a building at bulk rate prices from the Utility, and landlords bill tenants for electricity based on flat fees or formulas derived from the space they occupy. Occupants pay for electricity as part of a monthly bill, but their energy use is not individually tracked.
Electrical submetering is the measurement of consumption after the master meter. Submeters (also referred to as power meters, electrical meters, and energy monitors) are installed after the master meter to measure individual electrical load.
The Benefits of Electrical Submetering
One of the most exhaustive examinations of applying electrical submetering to commercial buildings was undertaken by the U.S. Department of Energy as part of the Federal Energy Management Program (FEMP) in 2007. This study showed that merely installing meters resulted in a 2% reduction in energy use through the Hawthorne Effect. 
It's Not Enough to Measure
Accountability and incentive are required to inspire improvement. No matter how you slice it, stakeholders must have visibility to the electricity they consume (and be responsible for it) if sustainable energy management is to occur.
Whether the goal is reducing energy use or just sharing cost equitably — without accountability, action will not happen in a viable manner.
H. James Harrington is an American engineer and international performance improvement and quality guru.
Accountability Means Paying
But it's not as straightforward as simply measuring electricity for energy management accountability. How you measure it, how accurate it needs to be, how you deploy your meters, and what you do with the energy data once you have it are equally important considerations.
It Starts with the Meter
- Multi-point vs single-point meters
- Approved electrical meters vs monitors
- Open systems vs proprietary protocols
- Meter maintenance and data management
Standards-based, open protocol meters help property managers and building owners avoid vendor “lock-in" and keep them in control of their data. They also ensure that the meters can keep pace with technology evolution and last for years to come.
Cloud-based energy management systems avoid these pitfalls and bridge the energy information gap by making data visible to all stakeholders — in a secure, as needed manner. They accomplish this by communicating concurrently with building automation systems over building automation protocols and information technology systems over internet protocols.
Data that was once only available to Facilities Management is now readily obtainable by anyone who needs to know. Operations personnel can monitor and maintain a metering network while property managers and building owners can access the data they need to make energy decisions.
Five Steps to a Successful Submetering Project
Complete the following five steps and your submeters will provide building owners and property managers with the information they need (when needed) to manage energy programs, save energy, and bill tenants.
- Clarify project goals
- Understand the electrical architecture
- Design meter deployment
- Install and configure the meters
- Meter commissioning
Being clear on your project's goals makes it easy to pinpoint the type and amount of metering equipment needed.
Utility billing and other revenue or performance-based applications, for example, will likely require meters that are approved by jurisdictional authorities. In contrast, energy management applications such as measurement and verification (M&V) or equipment consumption benchmarking can typically deploy non-approved meters.
Make a list of your project goals and all the stakeholders that need access to your energy information. This will inform the types of meters you require and what meter maintenance, energy management, and/or billing software you will need to deploy.
The best records of the electrical system of a building are the single-line electrical schematic
and panel schedules. These are readily available for new installations or facilities under construction. For older buildings, single-line drawings are often less accurate (if they exist at all), making a site visit mandatory.
The best records of the electrical system of a building are the single-line electrical schematic and panel schedules
Site visit information, coupled with knowledge derived from any electrical schematics or schedules that do exist, should be recorded in a standard, easy-to-read format. This allows the information to be shared between the project manager, electrician, system managers and support staff.
At Triacta, we use a spreadsheet system that supports both paper-based and electronic data collection. The spreadsheet information is compiled by those conducting the site survey and shared with the rest of the team so everyone works from the same base assumptions.
At this stage it’s essential to have a deployment platform that supports all aspects of your metering project — from meter installation, configuration, and diagnostics, to billing, measurement, verification, and system integration. For more on secure, cloud-based platforms for meter deployment, configuration, and management, see: The Importance of Cloud-based Meter Management.
The importance of a thorough site survey or single-line drawing analysis is emphasized at this point of the process. This analysis determines wiring and voltage configurations along with ampere ratings. Amperage determines the types of CT’s needed.
Under most building codes, installing multi-point meters requires a licensed electrician
Once installed, meters must be configured for the required application. Meter configuration includes the type of electrical service (i.e. 3 phase 3 wire, 3 phase 4 wire) and voltage and amperage requirements. Also, information about the communication network must be entered to ensure the meters report to the metering platform and any energy management, billing, or building management network as required.
Meter configuration is often performed onsite using a web page connection or specialized computer application. However, onsite configuration is not ideal as mistakes can be made during data entry that may not be discovered until later in the process. An alternative method is to pre-program meters before shipping them to the site. Unfortunately, this can cause issues if programming errors are discovered or suspected once technicians have left the site.
Triacta uses cloud-based software to configure meters. Once installed and reporting to Triacta Meter Manager, meters can be configured remotely — saving time and reducing costly site visits.
Beyond viewing energy consumption information, the metering network should be monitored to ensure ongoing success. A cloud-based management system allows for easy remote diagnostics, maintenance, and support.
Successful Energy Management Through Submetering
Multi-point submeters are the most cost-effective solution for the granular monitoring of a building's energy consumption — which is essential for any sustainable energy management program. Still, care must be taken to ensure that your metering platform is deployed correctly to realize all the benefits of submetering. Following the 5 steps outlined here will ensure a successful, cost-optimized deployment.
The bottom line is this. The key to jump-starting your successful energy management project is to deploy approved, standards-based multi-point meters. These systems are cost-effective, integrate easily with existing financial and energy management platforms, allow for staged and affordable implementation, and protect building owners and managers against ever-evolving industry standards and business requirements.