Who wants to invest in efficiency if their energy-hog office-space neighbor gets the credit -- and the savings?

This question, in one form or another, has been a major stumbling block for the otherwise commonsense idea of investing in energy-smart building technologies. Sure, efficiency is the fastest and cheapest green investment a building owner can make. But that cost has to be fairly measured, and fairly shared, to make it worthwhile to owners, operators and tenants alike.

Submetering helps solve that problem. By putting a meter at each apartment, office suite, mall storefront or other discrete entity in a multi-tenant building, you can start charging each customer for their fair share of power -- and incentivize each one to save for their own benefit.

Submetering discrete building power systems -- HVAC, lights, plug loads, common spaces, security and emergency evacuation systems, etc. -- can also help a facilities manager optimize each, whether it’s predicting which equipment is about to fail and replacing it, or running it when electricity is cheap and shutting down when it’s about to skyrocket in price.

Still, after decades on the market, submetering has only captured about 10 percent to 15 percent of commercial and multi-family residential building space, indicating that for now, at least, it has been seen as too expensive, too experimental, or too boring to choose as a focus for spending for building owners. (For more, check out our report, The Enterprise Smart Grid and a Corporate Buyer’s Guide for Energy Management Software.) 

Or maybe it’s too complicated. General Electric, a big player in submetering, hopes its new Multilin EPM 6010 may make it a little bit less so, via the ability to speak two of the three main building automation system standards: Modbus and BACnet.

Most of today’s BMS platforms integrate these two core building automation technologies, including those from Siemens, GE, Schneider Electric, Honeywell, Johnson Controls and others. Platforms like Honeywell’s Tridium software can translate these protocols, allowing system integrators to mix and match products from different vendors, or allowing building owners to integrate the systems they already have.

But that setup still requires the BMS to translate one protocol into another, much like translating Spanish into English, Bala Vinayagam, director of product marketing at GE Digital Energy, said. That’s a complicated programming task, requiring some software engineers to write the code to convert 5,000 to 10,000 Modbus mapping points into look-up tables for BACnet, or other such integration tasks, he said.

That can add tens of days, and hundreds of thousands of dollars, to the timeline and initial costs of a submetering deployment, he said. Every time a new BACnet technology is implemented, someone will have to write new translation code as well, adding future costs.

GE’s new Multilin submeter, on the other hand, speaks BACnet and Modbus natively, Vinayagam said. That cuts upfront costs of integrating submeters into building management systems, which should help push the magical payback and ROI figures even further into the black, he said, though he didn’t provide specific figures. (As with many of today's submeter systems, GE's new meter connects with building systems via a variety of physical communications, including Ethernet and Wi-Fi.)

GE isn’t the only one plotting growth in submetering. Pike Research predicts the market for submetering will double between now and 2020 to reach $1.58 billion globally. Honeywell bought 30-year-old submetering company E-Mon in 2010 for an undisclosed sum, indicating that it and other building giants see a value in the market. Submeters can earn buildings points in the U.S. Green Building Council's LEED ratings, which  has driven quite a bit of early adoption amongst clients, Vinayagam said.

What about connecting smart meters to submeters? For now, GE is keeping any such plans in the lab, he said. Indeed, Matt Lecar, a principal at GE Energy’s Smart Grid Strategy group, noted at a recent conference that utilities aren’t always that supportive of customers’ submetering plans, since it can lead to disputes about the bill compared to the utility’s master meter.

But that doesn’t mean more insight into building energy use won’t be critical to opening the door to more sophisticated ways of managing building power. Demand response company EnerNOC, a big energy efficiency player in its own right, integrates submetering into both efforts. Constellation Energy is thinking of submetering office buildings for efficiency competitions tracked by lobby displays from startup Lucid.

There’s certainly plenty of efficiency to gain. A 2009 Electric Power Research Institute (EPRI) report suggests that U.S. commercial and industrial energy efficiency potential is in the range of 258 terawatt-hours, and that efficiency plus demand response could shave 68 gigawatts from C&I peak loads by 2030, which would equate to a lot fewer power plants.