The Hawaii Gateway Energy Center (HGEC) visitor complex, situated on the south coast of Kona on the Big Island of Hawaii, serves the Natural Energy Laboratory of Hawaii (NELH). It is the first building to be constructed on a 6.5 acre campus designed to house research, development, and demonstration facilities for energy and technological fields. The NELH facilities are run by the State of Hawaii under the Natural Energy Laboratory of Hawaii Authority (NELHA).
The visitor complex houses administrative office space, restrooms, support areas, and a large multi-purpose space that will be used for displays, outreach, conferencing, and education. The first phase of the plan for the site also includes a small research laboratory facility. The second phase will add more laboratory space to complete the campus.
HGEC is designed as a thermal chimney, capturing heat and creating air movement using only building form and thermodynamic principles. Outside air is moved through the building at a rate of 10 to 15 air changes per hour without the use of a mechanical system.
The copper roof radiates heat from the sun into a ceiling plenum; the heated air rises and is exhausted through stacks on the building's north face. As the hot air is exhausted, fresh outside air is pulled into the occupied space from a vented underfloor plenum. Incoming air is drawn across cooling coils filled with 45°F seawater and cooled to 72°F. Condensation collected below the seawater cooling coils is used for flushing toilets and irrigating deep-rooted landscaping.
The building orientation and configuration allow daylighting to eliminate the need for electric lighting during daylight hours. All glazing is shaded to prevent direct solar gain.
The building was designed with an onsite, 20-kilowatt photovoltaic array. When the building was constructed, this provided about half of the total energy needed to run the seawater pumps, lights, and other electrical equipment. A pump adjustment in 2006 means that the photovoltaic system now provides all of the energy needed on site.