Originally published in Interiors & Sources

04/30/2013

Curbing the Energy Curve

An inch-deep, mile-wide strategy carries energy management across the portfolio of Duke Realty

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    Operational Savings from Analytics
    After systems were standardized on a common platform, Duke Realty began seeing operational savings in addition to energy savings. For example, the firm now has the ability to grant, deny, or change system access on its own, thereby avoiding charges. Also, advanced metering stimulates commissioning and recommissioning processes.
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    Correcting the Energy Curve
    The first step in curbing your energy curve is making sure that your demand syncs up with occupancy. Outside weather patterns are helpful for identifying load requirements. Once the curve is synced up, you can start lowering its height and monitoring drifts.
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    Identifying Short Cycling with Analytics
    The analytics package Duke Realty uses does all the heavy lifting. No technician or employee is required to interpret the choppy curves, because exceptions (or alerts) are displayed on the top bar. For example, the system will report if there is an unusual spike outside of the blue occupancy zones or if there are more spikes than should be expected.
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4) Monitor Drifts from the Curve
Duke Realty enlists a half-time-equivalent employee who interacts with reports from the program and communicates those to technicians in the field. Once the curve is optimized and lowered, it’s important to manage slides from optimum performance.

“If somebody overrides a system and then doesn’t take that override off, we want to catch that as quickly as possible so that it doesn’t stay on for any extended period of time,” Quinn explains. “The analytics package lets you do that because you get alarms or exceptions every time something is outside of parameters.”

The system doesn’t require a technician – either at the central location or in the field – to actively look for problems because any disturbance is automatically alerted via the interface.

“We look at these exceptions on a weekly basis. In that time frame we find a number of opportunities, and typically they are very low-hanging fruit,” Quinn explains. “Usually it’s something around the start-up or shut-down schedule or other kinds of setpoints that can simply be reconfigured and don’t require additional capital.”

Quinn has also identified when a building hits an annual peak usage or is within 5% of that mark. “At that point, we can call the field, asked what’s changed in the building, and see if something can be shaved to lower demand charges,” he says.

5) Drill Down Deeper
The next step is to strengthen your pulse. Duke Realty still has about 200 office buildings in its portfolio that aren’t equipped with metering or modern control systems, and the plan is to incorporate those incrementally.

“We have a company policy that says any new construction or retrofit must include this technology,” Quinn says. “So at this point, as buildings justify system replacements – typically because of age or breakdown – then those buildings will come onto the analytics platform.”

Duke Realty’s system also helps during the commissioning process, Quinn says.

“A contractor will only sample 10 or 20% of VAV units in a building and if they’re working correctly, he assumes all the others are. With analytics, we can look at every single unit and tell the contractor which ones aren’t working while he’s still in the building,” explains Quinn. “From a recommissioning perspective, if we have a tenant turn over and there’s major finish work and reconfiguration done in a space, we will pay more attention to the analytics after that to make sure we don’t have any balance issues.”

Additionally, the package helps Quinn turn an eye toward the future. Right now, Duke is investigating more centralized control.

“Facilities personnel are very busy and it’s hard for them to make time for more analytical and proactive tasks. Today, the analytics system does all the heavy lifting and identifies opportunities. Then we rely on the field to make those changes,” Quinn explains. “We’re experimenting with a model where we can make those adjustments directly from our central location. It takes one more point of resistance out of the process.”

Quinn is pleased with how analytics has streamlined the firm’s energy management intelligence. It has enabled the firm to lay its mile-wide framework and expand flexibly and incrementally over time.

“Start with something simple,” he says. “Then go an inch deeper.”

 

Chris Curtland christopher.curtland@buildings.com is assistant editor of BUILDINGS.

 


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