You can’t create something out of nothing, but the Northern California Chapter, NECA and IBEW Local 595 were determined to zero-out their energy bill for their new training facility. The result is the 46,000-square-foot Zero Net Energy Center in San Leandro, Calif., one of the few “zero net” energy buildings designated by the U.S. Dept. of Energy and the first achieved by retrofitting an existing commercial building.
The simple definition of a “zero net building” is a building with zero net energy consumption and zero carbon emissions annually. The Zero Net Energy Center (known as the ZNE Center) achieved this through a combination of smart energy conservation planning and innovation renewable power production. The building was officially opened in a grand ceremony with California Governor Jerry Brown and several local officials on May 30.
“Our training center is a model for what energy solutions can mean for building owners and architects, as well as a classroom and lab for our apprentices and journeyman,” said Don Campbell, Chapter Executive, Northern California Chapter, NECA. “We wanted to go beyond drawings and calculations to show what an energy retrofit really looks like.” Campbell smiled and added, “Well, not all the calculations are boring—the ones showing how much money we’re saving on our electricity bill are pretty impressive.”
Energy savings by the numbers
“We used new technologies, advanced building designs and innovative construction methods to achieve an unprecedented 75 percent reduction in energy use when compared to similar existing commercial buildings in the country,” Campbell said. “This energy savings lowers the ZNE Center’s carbon footprint by 175 tons of CO2 per year, equal to the carbon emitted by 30 passenger vehicles annually as well as a savings of 500 barrels of oil each year.”
Thanks to the significant energy conservation measures, less than 140 kilowatts (kW) alternating current (AC) of electrical energy will be needed for the electrical training center. ZNE Center’s renewable energy systems combining wind and solar photovoltaic (PV) generation will produce enough energy to meet the energy consumed by the building.
A powerful give-and-take for California
California has enacted stringent energy conservation requirements and renewable energy policies that call for zero net energy commercial buildings by 2030. Since breaking ground, state officials have closely watched the renovation and retrofits of the ZNE Center. The building showcases the training and expertise, as well as the technologies that promote energy conservation and renewable energy generation, that will help the state reach its goal.
In addition to being the first retrofit of an existing commercial building that meets the U.S. Department of Energy standards for a “zero net energy” building, the ZNE Center also exceeds the State of California’s 2030 energy efficiency effort by meeting the zero net goal 17 years in advance. It also exceeds the energy conservation goals of the Obama administration’s Better Buildings Challenge.
In October 2012, hundreds gathered to witness the ZNE Center’s renewable energy systems connected to the power. While zero net energy buildings are self-sufficient over a year, they occasionally require power from the grid when wind or solar production is low. These systems can also feed power back into the grid when they operate at a surplus, hence zero-ing out the power they use on cloudy or windless days.
California's publicly owned utilities, committed by law to reducing total energy consumption, have targeted new commercial buildings for most of the reductions. By 2030, the state goal for zero net energy extends to every new commercial building.
"We love to build large power systems. Our ZNE Center takes a different tack—energy conservation technologies are used to conserve power, so we are building a smaller power generating system. These technologies are [how we now] work," said Victor Uno, Dublin, Calif., Local 595 Business Manager. "Energy conservation and renewable power systems promote California policy and show the way forward."
Energy storage (aka, batteries) innovation has lagged renewable power generation technology. For now, zero-net buildings connect to the power grid so they can offload any excess electricity generated on-site (distributed generation). When the ZNE Center’s wind turbines are turning at full speed and the sun is blazing, its windmills and solar panels can produce 139 kW AC of power. The amount was chosen because it is 10 percent higher than the building would need with every classroom full, every computer fired up and every office in use. If energy conservation measures were not taken, a commercial building of the same size and type would have required a 550 kW AC to meet zero net goals.
ZNE Center design specifications
The ZNE Center exemplifies the importance of deep and early collaboration of the entire design and construction team. Under the leadership of IBEW/NECA, the team included Environmental Building Strategies (EBS), NOVO Construction, FCGA Architects, Belden Consulting Engineers, Red Top Electric, ACCO Mechanical and Cubed Energy Solutions.
Byron Benton, the training director for the Local 595/NECA apprenticeship program, oversaw the Center’s construction. He credits the advanced building automation systems that control lighting and ventilation for the tremendous energy reductions. NECA member Red Top Electric was contracted for the project.
Lighting makes up about 40 percent of an average building's energy use. In the new ZNE training center, every office and classroom has windows that flood the space with a bright, but even light. Ambient-light sensors in the room turn on LED light fixtures if more light is needed, and shades on the skylights and side windows can be controlled manually or automatically to darken the room.
The second biggest energy drain for commercial buildings is getting fresh air to each room at a comfortable temperature. The center uses multiple systems, most of them automated, to do the job as efficiently as possible.
There are automated windows on either side of the skylights that vent hot air, drawing in cool air from ground-level awning windows that are also automated.
"The windows, which are tied into the building automation system, will automatically open and shut as needed in conjunction with the variable refrigerant flow [VRF] heating and cooling system," Benton said. Instead of piping heated air from a furnace to vents throughout the building, the VRF system uses liquid and gas refrigerant to cool and heat the building. An energy savings component of this design is the ability to remove heat from one space and redistribute it to another location where heat is needed.
"In liquid form, refrigerant takes heat out of the surrounding area," Benton said. "Then you can take that gas in the system and redistribute to a part of the building that might need heating. So we aren't just independently heating a cold area; when possible, we are redistributing heat that is already in the building to where we want it."
Uno said that a simple principle informed the many complicated decisions they had to make.
"If there aren't any people or computers, we want everything off. Regardless of how efficiently the energy is generated, we don't want to use the energy if the space is empty," he said.
What makes the ZNE Center different?
"Most commercial buildings—even [in the Bay area]—don't allow open windows. They are sealed," Benton said. "What do they do? They manage a closed and sealed building. Recent studies show that buildings with natural ventilation are healthier. This factor along with increased energy levels, with the presence of natural light, equates to increased academic and work performance."
"We do automation and lighting control. We do renewable energy generating. The building management systems are all about automation," Uno said.
The key for getting a successful green installation is training, Campbell said. Correctly installing and then integrating these systems can only be done by highly skilled electricians with the right training. Incorrectly installed wind turbines and solar panels fail sooner and produce less power. Incorrectly installed building automation systems might not work at all. The ZNE Center provided area apprentices and journeymen with the ideal opportunity to put their skills to work.