The individual metering of building tenants – sub-metering -- is an important trend to which energy managers must pay attention. It is a tool which, along with energy management systems and building management systems, will drive efficiency by enabling increasingly granular and creative control of building resources.
Sub-metering to this point is more common in apartments and multi-family structures. The next step is its use in commercial buildings. Brian Glynn, MACH Energy’s Senior Vice President of Product Management, thinks that progress will be made on that front in the near future. “One of the things that will be interesting to watch is the sub-metering of tenant spaces,” he said. “New York City has a mandate to sub-metering for individual tenant spaces.”
While Glynn points to New York as a key growth area for non-residential sub-metering Claire Swedberg -- writing in Electrical Contractor late last year -- pointed to California and Texas as the biggest movers to date. In general, it is clear that more states and regions are getting into the mix. Sub-metering is the bookend capability to smart metering: The former separate tenants use and can distinguish between use by particular devices. The latter adds the smarts that make it possible to do something creative with the data:
The meters can be part of a network, or they can be connected directly to a server. One smart meter offers limited benefits, but when a network of meters is in use, the information gathered can yield information building managers never had before. Utilities use the data to better manage their own services, while building managers can identify and manage their own inefficiencies.
All eyes – or, at least, interested in sub-metering – indeed at on New York City. Last year, Local Law 88 took effect. Panoramic Power provided four highlights of the law, which goes into effect in 2025. At that point all commercial buildings of more than 50,000 square feet will have sub-metering, residential buildings with commercial tenants occupying more than 10,000 square feet also must be submetered and tenant bills must be based on actual consumption. “LL88” also has LED provisions.
Marc Karell, the Owner of Climate Change & Environmental Services, pointed out in a column last year at Energy Manager Today that while 2025 seems like a long time in the future, LL 88 is something that energy managers and landlords must pay attention to now, since commercial leases often have a term of 10 years. Much of the experience – and anecdotes – to date involve residential use of sub-metering. The basic theme is that tenants conduct themselves differently once sub-metering is in place. There is no reason to think that this will change once sub-metering moves to the non-residential world. Human nature will be the same. In this case that’s a good thing:
Also, many stories have been shared about how people — once sub-meters are installed — who now have to pay based on their actual measured usage, scream when they see their first bill, and then go out and buy more efficient lights and, of course, do not leave on their AC all day anymore. Several reports indicate that this effect causes a decline in electricity usage and a demand reduction averaging about 30 percent. This was the motivation for New York City to promulgate this rule in their effort to become more energy efficient and reduce the future infrastructure upgrades of unbridled demand.
“It will be interesting to see the transition,” Glynn said. “A tenant may go from a large server to monitoring usage and really get involved in their energy use and efficiency. My suspicion is that you will see going forward more regional government mandating more laws. I think in six months or a year you will see some of that.”
