How to Choose the Right Electrical Submeter
But how do you choose the right submeter for the job?
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 monitored or 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. 
- Do I need single or multi-point meters?
- Should my meters be networked?
- Do I need revenue-grade metering ?
Single or Multi-point Meters ?
Doing this using single-point meters would require a tremendous number of them. In these situations, multi-point meters offer several advantages over single-point meters related to hardware cost and deployment.
Multi-point meters have a much smaller footprint than multiple banks of single-point meters, and lower per meter-point deployment and maintenance costs. Additionally, in commercial settings where building configurations often change, tenant moves are more easily accommodated when multi-point meters are deployed.
Networked, Or Not ?
But the question is not just about the absence of networking. It's also about what kind of networking you choose. Integrating with other systems (financial, building operation, IT, energy management, billing, etc.) is critical in today's connected world. Choosing submeters that are local area network-based (ethernet or wireless) and IP-centric allows them to "speak" to other systems and enables integration today and tomorrow.
The language your meters speak is an important consideration too. The free and unobstructed flow of meter information to all stakeholders, systems, and applications with a need to know should be your goal. To ensure that your data remains in your control and can be easily used today and tomorrow, your meters should use open protocol, non-proprietary data formats.
Revenue-grade, or Not ?
Regulatory bodies are using the tried and true ANSI c12.20 0.5 accuracy class as the standard meters must meet — and requiring third-party laboratory certification to prove that they do.
To be clear, if a meter is only being used for internal purposes and not to bill tenants or receive financial remuneration, it does not have to be a regulated meter. In fact, there are no such rules for certification in some jurisdictions, even on financial transactions. But this is not a viable approach long-term — and regulation is destined to be introduced across North America.
So What's It Going to Be?
Ask yourself how many meter points you need to measure — today and down the road. If it's just a few, then single-point meters are likely the best route to go. But suppose you have several circuits to measure, and the allocation of those circuits is likely to change over time. In that case you might do better by taking advantage of the lower deployment, integration, and maintenance cost of multi-point meters.
Meters deployed today should be connected to a building's network. The cost-savings gained by avoiding manual meter reads and orphaned meters is reason enough alone. More compelling, however, are the benefits property managers and building owners gain when their energy data can flow freely to all of their building systems.
Benefits that include sending meter reads and pulse collection information to a billing agent while also sharing it with an energy management service for ongoing monitoring. Or being able to trial a new energy management analytics service while continuing to use your current vendor. You can only realize these benefits if you use IP-centric, open systems meters.
Lastly, there are many reasons for property managers and building owners to consider using regulated meters over non-regulated. The primary one being the requirement for an approved instrument of measure when allocating energy costs to building tenants.
But even if current objectives are not for billing, goals change. With the small total incremental project costs associated with using approved meters versus unapproved — it makes sense to keep your options open.
- Making the Case for Electrical Submeters
- Show You the Money? Show Me the Meter!
- From Space Saver to Information Cornerstone: The Evolution of the Multi-Point Electrical Meter
- How to Choose the Right Electrical Submeter
- Successful Energy Management Through Submetering, Part 1
- Successful Energy Management Through Submetering, Part 2