Producing as much energy as you use is the definition of a net-zero energy building (NZEB). Such efforts garnered a lot of attention in recent years, but have they moved from curiosity to marketability? Their numbers are small, but each new success could tip the scale toward market traction for this ultimate achievement in sustainable building operation.
NZEB examples can be found in schools, offices and homes. Drivers, such as the Living Building Challenge established in 2006, demand that every building pursuing its certification program achieve and maintain net-zero operation. Six projects are now certified, and 10 others are in the operational testing phase. In total, 90 are either in design, construction or operation.
The New Building Institute is working to improve the energy performance of commercial buildings and counts as many as 21 verified net-zero buildings in the United States (not including residential). It estimates as many as one hundred by year’s end, not including what it cites as zero-capable buildings that have the potential for achieving net-zero through adding on-site renewable energy. That could represent another 60.
Goal-setting also is building momentum. The American Institute of Architects’ “AIA 2030 Commitment” asks architects to commit to designs that offer zero carbon emissions by 2030. In its “Vision 2020,” the American Society of Heating, Refrigerating and Air-Conditioning Engineers is committed to providing its members with the tools to accommodate NZEBs (e.g., properly sizing and selecting HVAC equipment and better building integration with the heating, cooling and lighting systems). States, such as California, have set their own net-zero goals. In that state, all new commercial buildings after 2030 must meet a net-zero energy performance threshold. The same is true for new residential construction by 2020.
NECA/IBEW net-zero ambitions
The National Electrical Contractors Association (NECA) and the International Brotherhood of Electrical Workers (IBEW) have met a landmark goal. They opened what’s been dubbed the “Zero Net Training Facility” (ZNTF) in California this past June.
Located south of Oakland in San Leandro, ZNTF is the new Alameda County Joint Apprenticeship and Training Committee (JATC) training facility for NorCal NECA and IBEW Local 595. This 46,000-square-foot building is on its way to being verified as the first net-zero retrofit and is hoping to achieve the Living Building Challenge and U.S. Green Building Council’s LEED Platinum certification.
“Net-zero, or zero net, is not just a good idea unlikely to happen,” said Darlene Besst, director of business development/government affairs, NorCal NECA. “It has become a reality for us with this new training center. New ideas and emerging technologies evoke change. Growth of such buildings continues in California and elsewhere. They may currently represent a small percentage of our country’s infrastructure, but they are happening.”
“We [electrical contractors] want to set the example of how the world can conserve energy,” said John Hunter of Del Monte Electric Co. Inc., Dublin, Calif. “If we can train the next generation on how to install renewable-energy systems, we can change the way the world uses energy.”
Byron Benton serves as the training director for the IBEW Local 595/NorCal NECA apprenticeship program.
“We wanted a new building to showcase the work we do and found an existing building that allowed us to expand. When the idea of zero net was put on the table, we wondered if it was possible. After six months of study and planning, we realized we could do it as a retrofit. Two and half years later, we opened our new net-zero training facility at a cost equal to or below that of traditional construction approaches. The building now appraises significantly higher,” Benton said, noting the ribbon-cutting opening drew 600 people, including California’s Gov. Jerry Brown.
Though the automation and integration of all the building’s systems was challenging, it elevated the center’s energy efficiency to 75 percent.
“That is the equivalent of importing 500 fewer barrels of oil a year, reducing the building’s carbon footprint by 175 tons, and taking 30 gas-burning vehicles off the road each year,” Benton said.
The building’s operation makes it a classroom in and of itself.
“The very systems we’re training in are incorporated in the building,” he said. “It’s a real-world application of what you are learning. Students are able to integrate traditional mechanical and electrical with natural ventilation and natural light. They can witness how the ‘wild AC’ of wind power is rectified into DC and how an inverter gives us stable 60 hertz power for the grid. The way we’ve integrated our photovoltaic [PV] arrays has motivated us to develop advanced journeyman PV curriculum.”
Red Top Electric Co., based in Livermore, Calif., served as the electrical contractor. It was the company’s first net-zero project. Red Top installed a Solar World rooftop PV (154 kilowatts); a Solar Tree PV (11.25 kW), which tracks the sun’s rays for optimum generation and furnished by Envision Solar; and three wind turbines (4 kW each) provided by Element Power.
“We have done a lot of LEED buildings; I think over 20,” said Mike Curran, Red Top CEO. “The leading difference here was the degree of collaboration between the design and building teams, especially in preconstruction. There was a lot of ‘what if we did this?’. We did pricing exercises and found the right energy-efficient products. We worked hand-in-hand with the mechanical and other trades. From the electrical standpoint, the project represented a lot of what we do.”
Curran said that, if one system or installation was a higher cost, savings in another area offset it.
“This project clearly demonstrates what you can do when you put some smart minds together and figure out how to be optimally energy-efficient without raising your costs,” he said.
RedTop assisted in the build-out of several classrooms and training rooms in addition to office space for the JATC staff. Other enhancements to the building included a Lutron Quantum lighting control system, occupancy sensors, Lonworks/Echelon operable windows used in part for natural overnight cooling of the building, a Modbus data-collection system to monitor energy generation from the renewable-energy systems, daylighting sensors and tubular skylights to minimize or eliminate lighting loads, and roof-mounted Passivents ventilation for additional natural light and for venting in outside air.
A mass-merchant experiment
Corporations are entering the world of net-zero through high profile projects such as PNC Bank’s NZEB branch in Fort Lauderdale (4,900 square feet) that opened earlier this year. In October 2013, Walgreens is set to open a net-zero store in Evanston, Ill., just north of Chicago. If its performance is verified after some 12 months of operation, it will represent the first mass retail NZEB. The store features rooftop PV, wind turbines, geothermal technology, energy-efficient building materials, LED lighting and ultra-high-efficiency refrigeration.
“We have 8,000 stores, with plans to add up to 150 per year,” said Jamie Meyers, manager of sustainability for Walgreens, based in Deerfield, Ill. “Several of our stores feature sustainable elements such as lighting and energy management systems in more than 5,000 locations, but we never tried to put all the sustainable elements into one store until now. After numerous calculations trying to figure out how to generate more energy that we could consume, we realized net-zero could be a viable option to try.”
Meyers hopes the Evanston NZEB will show what systems work best together and can be applied in other Walgreens to make them higher performing buildings.
“We want to learn from net-zero,” he said.
The NZEB systems will be monitored, so customers can see how much power the building is consuming and how much it is generating.
“We will conduct continuous commissioning at least over a year’s time,” he said.
Spearheading early adoption
The Department of Energy (DOE) and the National Renewable Energy Laboratory (NREL) have spearheaded much of the work that is helping set the pace for NZEBs. The DOE’s Zero Energy Commercial Building Consortium continues as a public-private partnership in its goal to achieve marketable net-zero energy buildings by 2025.
NREL is verifying the net-zero operation of its new Research and Support Facility (RSF) in Golden, Colo. So far, its efforts are within one or two percentage points of net-zero, which would make the 220,000-square-foot facility the largest such project in the country. Advanced heat recovery developed and designed by lab researchers, 1.6 megawatts of installed PV and a power purchase agreement, daylighting, natural ventilation, and an energy-efficient data center are helping the RSF reach its optimum energy goals.
“Net-zero involves first reducing costs and achieving 50 to 70 percent energy savings through energy-efficiency measures,” said Paul Torcellini, principal engineer, Commercial Business Group, NREL. “Natural light and natural ventilation, economic lighting, efficient heating and cooling systems, and other integrated measures can get you close, but you need alternative energy to get to net-zero.”
Torcellini said certain building types are easier candidates, such as warehouses or smaller buildings like schools that have a daytime profile. More difficult buildings might be hospitals that require a lot of load and ventilation requirements.
“The market is ready for net-zero,” he said. “New and better technologies will help but owners need to think about how a building is really put together and integrated. Each new project that emerges serves as a demo of how it can be done in different ways. As more and more owners do net-zero, it will become less exotic and more routine as a building practice choice.”