Technology Spurs Growth in Zero Energy Buildings
Machine learning, the building internet of things, cloud-based advanced analytics all make it easier and less expensive to drive down energy use.
Zero energy buildings are growing exponentially. According to the New Buildings Institute’s annual Getting To Zero Status Update report, the number of verified zero energy buildings has increased 700 percent in the last six years. That huge increase is due in no small part to better technology, including everything from machine learning that can tweak a building in real-time to the rise of Building Internet of Things (IoT) devices and technologies that gather massive amounts of data, cloud-based advanced analytics to sort through it, and fault detection to alert facility managers when something isn’t quite right.
Zero energy buildings require an all-hands-on-deck approach in terms of energy efficiency, say experts, including a careful examination of building systems, plug loads, and incorporating renewable energy.
“Internet of Things is critical because to reach zero energy you have to squeeze out every kilowatt-hour you can,” says Robert Knight, senior associate, intelligent building practice, Environmental Systems Design. “You have to search out waste you didn’t know you had. That means not only having systems that are as efficient as possible, but looking for better ways to leverage those systems.”
Especially for zero energy buildings, then, Building IoT and machine learning must help create the intersection where design intent meets operational efficiency.
“Zero energy is a performance result, not a design outcome,” says Cathy Higgins, research director with New Buildings Institute. “There is a lot more demand to know actual [performance] in buildings.”
Facility managers can be forgiven for the urge to stand and cheer as this notion of connecting design with operations continues to gain momentum, both for traditional buildings generally, and also for zero energy buildings specifically. But how is Building IoT making that connection?
IoT is the bridge
In a traditional design process, an engineer creates an energy model based on dozens of assumptions about how the building will operate once it’s built. Sometimes those bear out, often they don’t. What’s different now, and what must be the case for zero energy buildings, is creating predictive energy models while the building is in operation. Building IoT technology and machine learning software are able to do this, learning about how the building should be operating, what factors are causing more energy to be used, and how to mitigate those issues without sacrificing occupant comfort.
Some call this process monitor-based commissioning. “The data helps keep you running in tip-top shape,” says Knight. Higgins adds: “IoT helps connect the data dots.” Essentially, the building can look for factors it decides are related, or that history shows have been related — correlations between outside air temperature and time of day, for instance. And then it adjusts set points appropriately. Or if the energy being used deviates too much from what the model predicts — what the building “thinks” it should be using — it can flag the problem and technicians can then go check it out.
Another area where Building IoT is helping make huge gains in energy efficiency is in location-based services. Building IoT can really help facility managers understand how and when people use a building, and how they move around in that building throughout the course of a day, says Knight. Knight emphasizes that all this data is anonymized to protect privacy. Each desk can be a Building IoT node, he says, collecting data about how often people use their workspaces. As well, occupancy sensors in common areas, Bluetooth beacons on occupants’ badges, and sensors on devices ranging from the coffeemakers to computers can accumulate data and analyze patterns of occupant use. This analysis, in turn, helps facility managers consolidate space into zones where they’re willing to spend energy.
More importantly, facility managers can keep occupants out of spaces that are mostly vacant so the building is not using lighting energy for one person in a conference room, for instance. Getting to zero energy requires focusing on every last bit of use, so, for example, using the BAS to turn on lights in a meeting room only when an approved meeting has been scheduled through a software module, is a possibility. Strategies like this may require some soft-pedaling with occupants, of course. It’s up to the facility manager to carefully explain the aggressive energy goals of the building and how occupants must be willing to help. “You must get buy-in from all the people,” says Knight. “Buildings can manage the HVAC and smart things can be done with lighting, but at the end of day, getting to zero is about how willing users are to take part in the goals.