HNEI expands energy research with solar net zero energy classrooms

University of Hawaiʻi at Mānoa
Jim Maskrey , (808) 956-3645
Associate Specialist, Hawaii Natural Energy Institute
Marcie Grabowski, (808) 956-3151
Outreach Coordinator, School of Ocean and Earth Science and Technology
Posted: Jan 14, 2014

Frog research platform at Ilima Intermediate School. Credit: HNEI, UH SOEST.
Frog research platform at Ilima Intermediate School. Credit: HNEI, UH SOEST.

As part of ongoing energy efficiency and solar research being conducted by the University of Hawaii at Mānoa's Hawaii Natural Energy Institute (HNEI), six solar photovoltaic (PV) arrays totaling 15 kW in capacity were recently installed in Hawaiʻi.  Emerging and innovative technologies are being evaluated and compared against traditional and well-established products in the solar industry.

Three net zero energy (NZE) buildings created by California-based Project Frog Inc. are the most recent experimental platforms used for PV performance research being conducted by HNEI.  The three state-of-the-art structures have been located at Hawaiʻi schools, one at Ilima Intermediate School in Ewa Beach, Oʻahu and two at Kawaikini New Century Public Charter School in Lihue, Kauaʻi.  Students will now have the unique opportunity to learn in new classrooms that are truly research and learning platforms in and of themselves.

According to Dr. Richard Rocheleau, HNEI Director, “These installations are part of a larger HNEI research endeavor to evaluate and compare the performance of traditional and emerging PV materials and inverter technologies.”  On these three Project Frog platforms, three PV materials are being tested: thin film technology, amorphous silicon and traditional monocrystalline silicon arrays, which has led the market since the 1970’s.  

Another variable to be evaluated is the effectiveness and efficiency of the inverters.  Inverters convert DC (direct current) power generated by the PV panels into AC (alternating current) in order to feed into the utility grid.  Two inverter configurations are being tested, a single string inverter and micro-inverters.  String inverters convert energy from multiple panels.  Micro-inverters are installed one per panel.

HNEI is leading the research study which will analyze the performance of these experimental buildings and integrated energy systems for potential future Navy applications in the Pacific region.  The research from these platforms will help scientists and engineers better understand and characterize performance under various environmental conditions. Each of the solar systems is equipped with a data collection system that allows university researchers to remotely collect data for detailed comparative analysis. 

An important aspect of these experimental buildings is the sophisticated instrumentation and monitoring being conducted to compare the performance of virtually identical buildings between the Kauaʻi location and the Oʻahu location.  Small differences in microclimate may have a significant impact on building performance.  The structures are outfitted with high-tech energy monitoring instruments providing valuable research data on the performance of design and material components. Data that tracks energy use as well as building comfort are measured, including temperature, humidity, CO2 levels, and lighting levels for comfort, as well as lighting, air conditioning and fan consumption for energy.  

The three 1,200-square foot, state-of-the-art structures installed in Hawaiʻi schools are the first two of three sites selected that will test the effectiveness these energy efficient buildings powered by renewable energy. The Project Frog pre-engineered test platforms incorporate passive design elements to decrease energy demand, thus increasing the effectiveness of its PV systems.

The design reduces energy consumption, construction waste and operating expense, while providing spaces that are adaptable for a variety of uses.  

"We are excited to play such an integral role in HNEI's research and together advance the science and technology behind new construction throughout the Islands," said Nikki Tankursley, director of marketing for Project Frog.

“Frog component buildings are responsive to the Hawaiian climate,” according to Ms. Tankursley. “With a small rooftop photovoltaic array, the classroom at Ilima Intermediate School produces more energy than it consumes.”

“This important assignment is part of a larger research program to evaluate energy technologies for the Office of Naval Research that includes a range of efficiency, storage, and renewable generation systems,” said Dr. Rocheleau.

The Office of Naval Research is providing funding for the project through a grant to the University of Hawaiʻi at Mānoa. This project supports the Department of Navy's energy programs to demonstrate technologies that enable increased implementation of alternative energy sources and promote energy security, made possible by the efforts of the late U.S. Senator Daniel Inouye, to ensure that the Department of Defense has adequate resources to make these critical, cutting-edge investments in energy technology.

The PV systems on both islands were installed by Risource Energy of Honolulu, Hawaiʻi.

Along with HNEI and Project Frog, project partners include State of Hawaiʻi Department of Education, and MK Think.