The Hawai'i Natural Energy Laboratory had a challenge when it wanted to build a state-of-the-art, energy-efficient "green" complex on the blazing hot, black lava of Keahole on the Big Island.

It met that challenge with innovation, and won a top national certification in the process.

The state hired the Honolulu firm of Ferraro Choi and Associates to design the $3.5 million project, which was funded by the U.S. Department of Energy. It was designed to be a campus for research and meetings on renewable energy and other high-tech issues, with an auditorium, exhibition space and other facilities to promote public education.

It was to employ advanced solar and cooling technologies, to be an example for alternative and distributed energy concepts, to minimize the use of potable water, and to use such things as the cold seawater from deep-water pipes off the coast from the Natural Energy Laboratory. It also was to use the greenest building-technology available, as defined by the U.S. Green Building Council's LEED program, for Leadership in Energy and Environmental Design.

The design won the LEED's Platinum Certification — the highest certification the program gives. The ratings are based on how projects do on making low impact to their sites, using water efficiently, conserving energy, using renewable resources and reducing construction waste, using daylight for lighting, reducing indoor air pollution and developing innovative designs.

"Probably the neatest thing is that the building is actually designed as a thermal chimney," said Bill Brooks, project architect and a partner with Ferraro Choi.

The Gateway center keeps air moving by using a design that naturally draws air upward using the natural tendency of warm air to rise. Incoming air is drawn over coils filled with cold seawater. The only electricity required for the system is for the pumps that bring the cold seawater to the facility.

The moisture that condenses on the coils is collected for irrigation and toilet flushing. No electric lights are needed during the day due to the way the design uses natural light.

The cold water is fed into underground tubes, which also condense moisture on the outside. That moisture irrigates all the vegetation around the building.

The result is that the ventilation, cooling and lighting of the building requires less than 20 percent of the power of a conventional building the same size.

If you have a question or concern about the Hawaiian environment, drop a note to Jan TenBruggencate at P.O. Box 524, Lihu'e, HI 96766 or jant@honoluluadvertiser.com. Or call him at (808) 245-3074.