Photo Credit: Pacific Northwest National Laboratory
Say you just bought a 15-year-old convenience store. You learn that the HVAC system has never been serviced. Digging into a stack of old utility bills leaves you wondering if your already slim margins are being eroded by the clunky air conditioner and the lights no one remembers to turn off in the storeroom.
You know retail, but terms like “energy benchmarking,” “commissioning,” or “retro-commissioning” might as well be a foreign language. And with those tight margins, you can’t afford to hire a team of experts and wait six months for answers.
The solution for this building owner, and for small commercial building owners everywhere, may be found in a portable case developed by two U.S. Department of Energy labs. The Sensor Suitcase, co-developed by Lawrence Berkeley National Laboratory (LBNL) and Pacific Northwest National Laboratory (PNNL), makes it possible for anyone to identify energy-saving opportunities that would typically require the hands-on labor and the expertise of a team of building engineers.
The researchers who developed the Sensor Suitcase say building owners who act on the recommendations can expect to save about 10 percent on their energy bills. According to PNNL, the owner of a 25,000-square-foot office building could save $3,500 annually by making recommended changes. If used by every small commercial building nationwide, U.S. energy costs would be reduced by $5.1 billion every year.
Here’s how it works. The user opens a padded case with 16 wallet-sized sensors nestled inside. The battery-powered sensors measure temperature, whether lights are on or off, and how a heating and cooling system is operating. Following step-by-step instructions provided by the operations software hosted on a separate tablet, the user affixes the sensors to locations throughout the building -- on lighting fixtures, near thermostats, and on the rooftop HVAC system.
About a month later, the user gathers the sensors, returning them to their slots in the suitcase. Harvested data is transferred to a personal computer, and analytical software developed by researchers at LBNL crunches the data.
Out comes a report complete with building-specific energy-saving recommendations such as installing occupancy sensors -- which would address our convenience store owner’s always-on storeroom lights -- or adjustments to HVAC settings. Each recommendation also comes with an estimated savings for addressing the problem.
The Sensor Suitcase was developed with the hard-to-reach small commercial buildings sector in mind. “The motivation for the suitcase was to think about a very streamlined technology solution that could allow you to capture as-operated data from the site, get in and get out with a measurement-based understanding of the potential opportunities -- and with very little time and cost,” said Jessica Granderson in an interview. Granderson led LBNL’s suitcase development team and is deputy director of the lab’s Building Technology and Urban Systems Division.
The Sensor Suitcase developers see a huge untapped market. A PNNL report published in June found it would be possible to slash commercial building energy use in the U.S. by 29 percent with widespread use of controls.
According to the most recent DOE data, there are at least 5.6 million commercial buildings in the U.S. Small commercial buildings -- those 50,000 square feet or smaller -- account for 44 percent of commercial building energy consumption.
And the vast majority of those small buildings lack the resources to undertake traditional retro-commissioning -- the process used to optimize the performance of equipment in existing buildings.
Granderson said the Sensor Suitcase can do much of the same work as a traditional retro-commissioning assessment in four to six weeks, compared to six months or longer, and at one-third the cost.
Real-world trials conducted in California demonstrated the potential for the researchers’ estimated savings.
“We did field-test the suitcase with a couple of partners and small facilities and found that the types of issues that were detected, and the nature of the recommendations, supported the target of uncovering opportunities that would amount to about 10 percent savings,” said Granderson.
In June, LBNL and PNNL announced that the Sensor Suitcase had successfully completed the journey from lab to market. Orlando, Florida-based energy-efficiency solutions company GreenPath Energy Solutions was the first company to license the suitcase.
GreenPath CEO Samuel Graham said he believes the Sensor Suitcase will enable his firm and others to penetrate the underserved small commercial buildings market.
“A lot of large buildings -- 200,000 or 300,000 square feet -- have always been doing commissioning and retro-commissioning. But a lot of smaller buildings -- 20,000 square feet and under -- have been priced out of the market because these services are somewhat expensive. This technology drops that price point down to where smaller buildings can afford the retro-commissioning-type services," said Graham.
GreenPath plans to both sell the Sensor Suitcase itself, via a third-party manufacturer, and use the suitcase to sell customers its existing energy benchmarking, energy auditing, and retro-commissioning services. The labs’ development teams suggested a sale price of $1,200-$1,500 for the Sensor Suitcase, based on the research prototype.
Michael Brambley, a scientist at PNNL who led the lab’s Sensor Suitcase team, said the suitcase could sell for as low as $500 with potential cost reductions achieved via mass production.
GreenPath signed a non-exclusive licensing agreement with PNNL, noted the lab’s commercialization manager, Sara Hunt, in an interview. The national labs, as well as Graham at GreenPath Energy Solutions, said interest in the technology is strong -- even before the Sensor Suitcase enters service in the field, which Graham expects to happen sometime in the third quarter of 2017.
Hunt said entrepreneurs looking to form a startup, existing startup companies, and very large international companies have inquired about the suitcase.
"We've received many inquiries from prospective users of the technology really wanting to know, 'How can I get my hands on the suitcase? Where can I buy it? How can I start using this in my business offerings, in my programs, in my day-to-day activities?'” said LBNL’s Granderson.