By Gordy Slack
The formidable, fifty-year-old Cory Hall, home of Berkeley’s Electrical Engineering Division, is a vortex of energy consumption. The fifth-most energy consumptive building on the entire campus, it houses, in addition to standard classrooms and offices, numerous instrumented instructional labs, a micro-fab facility filled with high-load semiconductor processing equipment, labs with fume hood installations, a machine shop, an energy-intensive data center, overused elevators servicing six stories and mezzanines, and notoriously inefficient ventilation equipment.
The whole building draws an average one megawatt of electric power—between 3–5% of the campus total. Where is all that electricity going? Ten months ago, David Culler and Paul Wright of i4Energy received a grant from the California Energy Commission to rig the building with sensors and find out. The project, known as Cory Hall Sub-metering Energy Efficiency and Dynamic Control Testbed, or the Cory Hall Testbed for short, installed a network of monitoring equipment to track the flow and use of electricity. Most of the meters are off the shelf, but the researchers brought in a lot of new IT to the project. Once the group could track where the electricity was going when, it would be able both to better manage it and, even more importantly, to use the building as a testbed for further research.
“The Testbed will be an i4Energy "user facility" providing a well-instrumented setting for several different kinds of researchers to work together to develop and test new methods for monitoring and control,” says Carl Blumstein, Director of the California Institute for Energy and Environment (CIEE).
In the Cory Hall Testbed’s nine-month-long first phase, the building was successfully wired with sensors that use an open standards-based system for communications and networking, even in this deployment phase, the research team, led by Professor Culler, learned a lot, says Scott McNally, Director of Space Planning and Facilities at Cory.
McNally, remembering one day in the spring when the sensors had not long been in place, points to a photo of a huge air conditioning unit on the roof of Cory and shakes his head. “It was going on and off all day. At some point I said, ‘Hey, it is 50 degrees outside, why are we using the air conditioner?’ Obviously, something was wrong. I made a phone call and luckily, through our digital control systems, we could call it up and see what was going on.”
It sounds ridiculous, he says, but they were both heating and cooling one large room at the same time. “The sad thing is, this happens in buildings all the time. It is just not known. Facilities tend to be under-funded, understaffed, and very reaction-oriented. If it is too hot, staff members run up on the roof and turn on the chiller. They do not have time to analyze the system. But these monitors are giving us tools to identify where we are wasting energy.”
“I can look at the piece of equipment, or at the panel, or at a breaker in the basement, or the whole building usage,” McNally says, “and I can see what is going on.” Even after bringing in the team to fix the simultaneous heating and cooling problem, the chiller was going a lot of the time. This was due to the manual over-ride switch, which was still on. The system allowed us to discover that.
The system is, in places, already quite specific, measuring not only how much energy is being consumed, but the service that that electricity is delivering. In the future, that will allow for constant demand-response-type regulation, where less time-bound tasks are conducted when there is less demand on the grid and electricity is more plentiful and affordable.
One planned use of the testbed is the installation and testing of novel prototype MEMS devices for lower cost networks of voltage and current sensors. These miniature, wireless, passive proximity sensors (WPPS) will also facilitate the development and study of new wireless communication techniques, advanced methods for affordable monitoring of building energy use, and conservation strategies. Data gathered from the tried-and-true but larger and more expensive commercially available sensors already installed will serve as an all-important baseline.
“Before you can do good control,” says Blumstein, “you need to do good monitoring. These new inexpensive sensors would allow easily installable, self-powering, and accurate monitoring. There is a huge payoff for improved controls, particularly in big complicated commercial buildings. If you understand where energy is going, and if you have competent operators to respond to that information, you can reduce consumption by 20 percent or more. But, the first step is to get your arms around what is really going on.”
“The infrastructure we have put in place can also guide us as we extend beyond Cory Hall to other buildings,” says Paul Wright, the PI on the project. “Soda Hall and Sutardja-Dai Hall, the new CITRIS Headquarters, would be good next candidates; both pose interesting challenges. Eventually, we could potentially extend to the rest of campus,” he says.
Inexpensive sensors allow easily installable,self-powering, and accurate monitoring for energy use in large buildings.
“Just being aware of their behavior’s impact on energy use will motivate the buildings occupants to adopt more energy efficient behaviors,” says McNally. The awareness of others might not hurt either; eventually, all the data will be made accessible, in real time, on the web. Already, some students working on the project have programmed and installed small icons on their computers, displaying the energy use in their specific work area or part of the building.
The Berkeley team is also working with the Smart Grid Center at California State University at Sacramento to allow it to take the knowledge gained from the Cory Testbed’s efforts and transfer them to a place where they can make an impression on state legislators and on the smart-grid community at large, says Wright.
The building has been evolving toward higher complexity and energy opacity since it was erected half a century ago. “It will continue to evolve,” says Wright, “but I see it evolving in a much cooler direction in the next fifty years. Cory was designed with the same consumption-blind ethic as other big buildings of its day: build it and pump as much electricity into it as it draws. Electric power went in, but no information came out. That has got to change. We cannot afford that approach any more.”