Testing Efficient Lighting and Building Control Solutions at Berkeley Lab: The First FLEXLAB Module Takes Shape
As clouds pass in front of the sun, incoming daylight is reduced in the interior of a section of the fourth floor of an office building at Lawrence Berkeley National Laboratory (Berkeley Lab). In this new lighting and plug load testbed, light sensors read the change in light levels, and energy-efficient ceiling fixtures gradually increase their light output to compensate.
Sensors on every light fixture report power consumption data in real time for recording, while other sensors measure ambient and desk-height light levels. The clouds drift away, incoming sunlight intensity increases, and the louvers of motorized blinds automatically realign themselves to maintain a comfortable, glare-free light level in the fourth floor's interior while the automated control system dims the overhead lights.
Sensors measure every significant variable and send data continuously for recording and later analysis by building scientists in the Environmental Energy Technologies Division (EETD). Office workers in the space are aware of the dynamics taking place around them but pleased the conditions are always maintained in the comfort zone.
This is a time of tremendous creativity and innovation in the buildings industry. The industry is working to meet the economic and social goals of designing and constructing buildings that use far less energy than today's conventional buildings. Manufacturers of lighting, HVAC equipment, building envelope products, and energy management systems are all developing new technologies. Their work promises greater energy efficiency, more comfortable interiors, and more knowledge about (and control over) building energy use and the interior environment than ever.
But the buildings industry will not adopt new technologies and systems without proof that they actually save energy under real conditions and make building interiors more comfortable and easier to control. New commercial buildings cost tens to hundreds of millions of dollars and have service lives lasting for decades. Owners and builders won't take a chance and install unproven technologies whose performance may fall short.
Now under construction at Berkeley Lab is a unique research and demonstration facility that will help industry develop and fine-tune new building technologies. It will also generate accurate, unbiased performance data. The Facility for Low Energy eXperiments in Buildings (FLEXLAB) will consist of four new outdoor test modules, as well as several testbeds within an existing building. It will be operated by the EETD, which is seeking industry partners for cooperative research. Read more about it here.
In FLEXLAB, Berkeley Lab and its partners will conduct research and product development on single components or whole-building systems integration. They'll be able to replace any building system such as exterior building envelope, windows and shading systems, lights, HVAC, energy control systems, and roofs and skylights, as well as interior components such as furniture, partitions, and raised floors.
While construction of the new outdoor facilities gets under way, another part of FLEXLAB has completed construction: the lighting and plug load testbed, and a virtual design testbed.
Unmatched Control of Lighting and Plug Loads
The lighting and plug load testbed is the most densely instrumented and minutely controlled building space anywhere in the United States—a stretch of building so finely regulated that every power outlet is individually monitored and can be turned on or off; every light fixture in the office cubicles is individually metered and controlled. "This is more advanced than any other facility in the buildings industry," says Steven Lanzisera, one of the researchers on the testbed's design team.
This 4,000 square foot floor area has room for 15 cubicles plus a row of perimeter offices along both sides of the building (eight in all). Francis Rubinstein, who helped design the testbed's lighting system and controls, says "every single light fixture in the testbed will be individually monitored. We can control the lights in the four rows of overhead fixtures in eight-foot segments. We'll also be able to measure the input power along each eight-foot segment."
"The ability to control and measure each fixture individually is unique to this testbed," says Rubinstein. "You don't get this level of control in any other test facility."
Rubinstein also adds that occupancy sensors control the energy-efficient LED task lighting fixtures in each cubicle. The occupancy sensors can turn them off when the occupant leaves. Fifteen ceiling-mounted photosensors can measure the illumination distribution throughout the study space. Additional photocells are installed at the tops of partitions separating the cubicles, as well as at the desk surface as required to adequately sample daylight conditions as they vary across the day.
Researchers will test different control algorithms for dimming electric lighting up or down to balance the daylight in the space, as well as for controlling automated fenestration systems.
"A lot of flexibility is built in to the algorithm to allow for individual control," says Rubinstein, "with the end result that we have a densely instrumented living laboratory that we can use to test real-life situations, mixing a variety of automated control strategies with manual control by occupants."
Control is in the Software
"A unique feature of the testbed," says Lanzisera, "is that all control is done in the software of the control algorithm—outside of the hardware."
"Traditionally," he continues, "controls are internal to the hardware, but here, all the control algorithms are on the outside, and the sensor data is logged continuously, and viewable using Labview software. If someone has a control methodology they want to test, it's easy to implement in the software."
This arrangement lets teams of researchers study how individual decisions are made about light levels and equipment energy use, and what sensory input went into the decision-making process. Their observations will lead to better algorithms for controlling system-wide energy use.
Protocols for Maximum Performance
"We envision a series of experiments in cooperation with private-sector partners to study the performance of new lighting controls and plug load technologies involving lighting fixtures, power supplies, plug strips, and software technologies for shedding load [reducing power consumption during periods of heavy demand]," says Rubinstein. "We hope to conduct experiments that will allow us to test several different technologies at the same time, and develop control strategies to maximize the energy savings and maintain comfortable conditions within the space."
Another purpose of the testbed is to study how design intent behind use of technologies matches up to actual performance, and to work out control strategies that allow building operators to get maximum performance. "We'll be documenting system installations, the commissioning procedures we used to ensure they meet their design intent, and how to operate the systems for highest performance," says Rubinstein.
Discussions Under Way Now with Potential Partners
While the outdoor testbeds are designed for use as unoccupied spaces with simulated occupancy, the lighting and plug load test lab will be fully occupied by EETD staff. After construction on the lighting and plug loads testbed was complete, the testbed was commissioned, and the facility was reoccupied by staff in October. The first team of industry partners is currently planning a test program to be implemented starting in late 2012.
FLEXLAB staff are now in discussions with other potential partners to develop a program of cooperative research in the lighting and plug loads testbed, as well as for the rest of FLEXLAB, whose centerpiece is the four-module facility, which will be finished in the winter of 2013.
Berkeley Lab invites interested partners to contact FLEXLAB staff for more information about how to perform research with us in the new facility and demonstrate new technologies and systems that will help achieve aggressive new performance goals for America's building stock.
For more information:
- Lighting Controls
- Francis Rubinstein
- (510) 486-4096
- Plug Load Controls
- Steven Lanzisera
- (510) 486-4762
- Partnering Opportunities
- Oren Schetrit
- (510) 486-5649
Facility for Low Energy eXperiments in Buildings (FLEXLAB) website.
The FLEXLAB facility is funded by the U.S. Department of Energy.