Researchers From National Renewable Energy Laboratory Review Green Building Technology

Researchers From National Renewable Energy Laboratory Review Green Building Technology

Nov 05 - Daily Journal of Commerce (Portland, OR)

Is green building technology all that it's cracked up to be when it comes to operating performance and efficiency?

Researchers from the U.S. Energy Department at NREL, the Colorado- based National Renewable Energy Laboratory, say yes, even though the actual performance may not always live up to the pre-construction hype.

The researchers are going through a final review of six buildings to see how goals for operating efficiencies matched up with actual performance. Each building was constructed with green features such as daylighting, radiant heating and photovoltaic panels.

In a separate study, researchers from the Weidt Group are studying green technology at the Science Museum of Minnesota's Science House, a 1,000-square-foot structure that's designed to produce as much energy as it consumes on an annual basis.

Energy consumption in the six buildings being studied by NREL was higher than predicted in some cases, according to researchers. Daylighting in particular had less of an impact on energy savings than was expected, and other systems weren't always installed as designed.

But the buildings - located in Ohio, Utah, Colorado and Maryland - still performed better than required by code while also meeting goals that can't be measured by dollars and cents.

Paul Torcellini, a senior engineer at the National Renewable Energy Laboratory and a participant in the NREL study, said one of the study's goals was to come up with real, measurable data to show what does or doesn't work in green technology.

In general, he said, buildings seldom perform quite as well as they are predicted to. Predictions for rooftop photovoltaic panels, for example, may not take into account snow covering or other impediments.

Daylighting is another example. The idea of bringing more natural light into a building makes sense, but energy savings occur only if the building's occupants resist the urge to flip the light switch.

I think we have a lot to learn about daylighting and getting daylighting in buildings so people feel comfortable turning the lights off, Torcellini said. Daylighting in commercial buildings is probably the No. 1 savings area, but if you don't turn the lights off, you're not saving any energy.

But Torcellini emphasizes that saving energy is only one incentive for using sustainable building techniques. Green buildings are successful, he said, if they meet the owner's goals.

They have different objectives, he said. One of the interesting stories is that people don't necessarily make decisions based on cost efficiency, especially when it comes to integrated design, where the form of the buildings follows what you're trying to do and what your image is.

One of the projects under study was the Big Horn Improvement Center in Silverthorne, Colo. The center, which includes an 18,400- square-foot retail area and a 24,000-square-foot warehouse, uses natural ventilation, daylighting, hydronic radiant floor heating and other green design elements.

With help from those features, the building's owners are saving about 54 percent in annual energy costs, according to a September 2004 ASHRAE Journal article. The upfront building cost was about 10 percent higher than conventional construction.

One of the disappointing design features - at least in terms of energy savings - was the photovoltaic system, which accounted for only about 2.5 percent of the building's annual electrical energy.

Nevertheless, the building's owner has gotten a lot of free press out of saying he has a green hardware store, Torcellini said, adding that's a big consideration. The photovoltaic panel is probably not cost-effective in its own right, but people equate it with green construction.

People make decisions based on values. Money is part of that value, but business sense is probably a bigger part of the value. What is the image that my building is going to portray? Is it going to be durable?

Steve Heins, marketing director for Plymouth, Wis.-based Orion Energy Systems, a provider of energy-efficient lighting, said businesses are sophisticated when it comes to choosing technology.

Green technology in general has been a tough sell at times, he said. Still smarting from pie-in-the-sky claims of efficiency and performance, some building owners remain skeptical.

That's been a major stumbling block, Heins said. Too much has been promised, too little delivered in the past. That's why the ability to measure and verify has been so important.

The intangible benefits of green building are great, Heins added, but the bottom line is still what matters most when it comes to selling the technology.

It seems to me that if we are going to accept (green technology), people have to feel comfortable that they are really going to save energy, he said.

The Science House - a 1,000-square-foot building in the Science Museum's Big Back Yard - is designed to move people into that comfort zone.

The building, constructed on a residential scale but designed for commercial use, saves energy by using a combination of sustainable technologies, including a solar photovoltaic metal roof, a ground- source heat pump, energy-efficient windows and spray-in foam insulation.

Tom McDougall, vice president of the Minnetonka-based Weidt Group, said the building has been performing about as well as expected. More importantly, it's a miniature laboratory for measuring green technology.

Measurable feedback on performance is one thing that's been missing from the sustainable design movement, McDougall said.

Seeing how they're performing and learning from that is going to be key, said McDougall, whose company provides design assistance for high-performance buildings. Otherwise, it's just kind of smoke and mirrors, and that's not good economically for anybody.

McDougall said the performance data should put to rest some of the skepticism about green technology that lingers from the passive solar era of the 1970s.

I saw a lot of that (passive solar) fail, and then there was kind of a lull in this thing in the '80s and early '90s, he said. That's why I'm so excited about measuring stuff, learning about it and debunking myths.

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