By Bob Geiger
Dolan Media Newswires
Minneapolis — The holy grail of energy-efficient architecture — a building that would generate as much energy as it uses — may be a big step closer to reality.
Minnetonka-based energy design consultant The Weidt Group Inc. and architectural firm HOK have spent plenty of energy over the past year developing a prototype of just such a structure, and they unveiled their prototype recently during the Minnesota American Institute of Architects convention at the Minneapolis Convention Center.
Three Weidt Group executives presented the zero carbon office building prototype to a crowded hall of executives. The prototype, using off-the-shelf technology, would pay for itself in 10 years and would qualify as a zero carbon, or net-zero, energy building.
David Eijadi, principal and owner of The Weidt Group, and firm executives Chris Baker and Vinay Ghatti presented the four-level, 170,000-square-foot building that would use solar energy, building placement and materials to qualify as a net-zero building.
Eijadi said commercial buildings are responsible for 39 percent of carbon dioxide emissions.
And, while the Weidt/HOK team managed a 12- to 14-year payback on building costs, Eijadi said the effort was an important design milestone of how far energy design and architecture can slash carbon emissions in an office building.
In June, just as The Weidt Group and HOK were finishing their zero carbon office building prototype, the U.S. Department of Energy awarded $76 million in stimulus money to support advanced energy-efficient building technology, including net-zero projects.
Among 12 net-zero projects was $1.4 million in stimulus money for Honeywell International Inc. to pay the majority of a $2.3 million project at the company’s Golden Valley, Minn., building.
The Department of Energy wants to reduce carbon emissions because they contribute to climate change, so The Weidt Group and HOK focused on designing a building that produces at least as much emission-free renewable energy during a year as it consumes.
The prototype, called Net Zero Co2urt, used an 80 percent efficiency model for the four-story structure, which includes two 300-foot structures spaced to maximize exposure to the sun.
Remaining energy required to reach the net-zero emission level was achieved by using about 52,000 square feet of rooftop photovoltaic panels and 15,000 square feet of solar thermal tubes.
The two 300-foot-long office structures, positioned east-west, are connected by two 60-foot links that enclose a courtyard for building tenants.