ASU’s Biodesign Institute LEEDs the way in rooftop solar energy

During most daylight hours, sunshine showers the state of Arizona with clean, inexhaustible energy. The trick is knowing how to grab it. Arizona State University, situated in one of the most sun-splashed environments on earth, is at the forefront of the solar revolution. Recent advances in photovoltaic (PV) technology combined with spiraling energy demands and a new ethos of sustainability have spurred a global bonanza in solar energy. Boasting 330 days a year of penetrating sunlight, the ASU campuses have become a Mecca for solar technology.

Part of ASU’s dedication to solar power can be seen atop the Biodesign Institute, where large arrays adorn the rooftops of its modular buildings A B, supplying the latter with 15 percent of the structure’s energy needs. In addition to lighting and climate control, sun energy helps to power the Institute’s myriad computers, high tech equipment and freezers for storing biological materials. Both Biodesign A and B buildings have been LEED certified (Leadership in Environment and Energy Design). Building A meets Gold LEED requirements while building B has been declared a Platinum LEED structure, a designation given by the US Green Building Council to construction projects garnering the highest marks for sustainability.

Sol Man
Mike McLeod, director of facility services at the Institute, and campus guru on all things solar, describes the rooftop project: “Here at Biodesign, we have a 280,000 kilowatt hour per year solar generating system that has just been completed. It has over 800 panels connected in series, producing a total of 400 volts.” Biodesign’s sun system is part of the solarization of ASU—the most ambitious campus solar undertaking in the United States. McLeod, a 30-year veteran in managing complex, eco-friendly facilities, knows the Biodesign Institute inside and out, having played a pivotal role in the design, construction and move-in phases of development.

Biodesign’s solar panels, which float on top of a concrete block ballast system, are set in place at a fixed angle of 10 degrees, providing optimum sun exposure throughout the day and over the course of the year. As McLeod explains, the particular solar cells used for Biodesign are known as polycrystalline and deliver the best value for the dollar. In terms of cost, polycrystalline cells fall in between the less expensive amorphous or thin film units and monocrystalline solar cells, which deliver the highest energy output but remain prohibitively expensive for many applications.

Each of Biodesign’s polycrystalline cells converts energy from sunlight striking its surface, to storable energy useful for human needs. The cells are connected together in series to form a module or panel. Each of these panels generates between 20 and 205 watts. Multiple solar panels combine to form arrays, which are linked in parallel. The radiant energy absorbed by the arrays is run into the lower floor of Biodesign, where a voltage regulator maintains a constant 400 volts throughout the day.

Biodesign facilities project coordinator Tom Mason, who along with McLeod, managed the solar installation with local utility APS Energy Services, says that the system is easy to monitor. “We have a DC to AC inverter box that feeds the power from the solar panels to the institute and is seemlessly integrated into our automated controls system for round- the-clock remote access and monitoring.”

The solar panels require little or no maintenance once installed and have a typical lifespan of 30 years or more. Ultimately, the harmful effects of ultraviolet rays degrade the efficiency of the cells, but there is emergent technology that seeks to extend this lifespan. Though some degree of pollution is involved in the manufacturing process, a finished solar generating system delivers completely clean energy, even on cloudy days.

The solar project at Biodesign is just one component in ASU’s ambitious, tri-campus initiative that will generate a whopping 9 MW of energy, capable of satisfying 22 percent of the university’s energy requirements, for all three campuses. Completion of the plan will occur over the next two years, blanketing over a million square feet of space with sun-gathering photovoltaic cells. McLeod puts the project in perspective, pointing to substantial energy savings and benefit to the environment. “Twenty-two percent of the nation’s largest university will be supplied by sun energy, saving some 15 thousand tons of carbon from being liberated into the atmosphere and contributing to global warming, ” he notes. 9MW of power yields enough energy to supply the yearly needs of over 1000 homes.

Sunny forecast
Arizona State University’s renewable energy portfolio is undergoing rapid expansion under a mandate from the President Michael M. Crow, who hopes to direct campus energy use away from fossil fuels and toward clean renewables. Crow’s energy leadership has already catapulted ASU onto the short list of institutions vying for the title of greenest American campus, with a goal of total carbon neutrality. As McLeod says, “Here at ASU, we’re not only talking about sustainability, we’re walking the walk. We want to be the role model for the nation. Not only are we developing this 9 MW solar generating system, we also have a global institute of sustainability, which teaches sustainable management, and also runs projects on campus and in coordination with industry to further the cause of sustainable power generation.”

Across the state of Arizona, a solar storm is brewing, with solar panels poised to become a ubiquitous part of the landscape, powering schools, businesses and homes. As McLeod notes, the state could meet 150 percent of its energy needs through solar and other renewable energy by 2019, perhaps selling the surplus energy to sun-starved states. Further, broad application of solar and other renewable technologies could reduce the average household’s carbon footprint from some 7.5 tons to less than a half ton, a generous contribution toward a sustainable future.

Joe Caspermeyer, Media Relations Manager & Science Editor
(480) 727-0369 | joseph.caspermeyer@asu.edu

and

Richard Harth
Science Writer
Biodesign Institute
richard.harth@asu.edu