Field of Beams: SMU Solar Array is an Online Teaching Tool

Capturing energy from the sun lessens carbon footprint

 

July 12, 2010

DALLAS (SMU) — With the summer sun high in the sky, a new field of solar panels installed at SMU is generating enough energy on most days to power 336 laptop computers for eight hours.  But the real value of the solar array may be in teaching area schoolchildren the value of electricity powered by the sun.

SMU installed its 68-panel solar array on a low roof adjacent to the University’s central plant where it produces about 81 kilowatt hours of electricity on an average, sunny day. That’s a relatively small contribution to SMU’s overall energy needs now, but Michael Paul, SMU’s Executive Director of Facilities Management and Sustainability, expects the Patterson Hall panels will be the first of multiple solar installations on the campus.

“We want to share what we learn about this system with anyone who is interested - especially K-12 students,” Paul said. “It’s really for demonstration purposes. Our engineering school researchers get a lot more access, the students get to see it as a normal item around campus, we get to see how easy it is to maintain and, as the price comes down, we get to look at other applications.”

While his staff studies ways to improve the array’s performance, a special on-line feature allows anyone to monitor the energy the system is producing in real time. With the click of a mouse, the SMU installation becomes an instant science lesson that uses time-lapse animation to demonstrate how the solar panels absorb the sun and transform it to energy during specific periods.

 As the sun tracks across the sky, each panel registers the wattage it is producing, glowing a lighter blue as the sun rises higher.  The panels on the west side of the array are the first to go dark at the end of the day as the walls of the Hughes-Trigg Student Center block the setting sun. (See live readouts from the array.)

Graphics on the site allow the user to compare highs and lows in energy production across the days and months since the array was installed in November 2009.  Some of what has been recorded so far can be surprising to the layman: For example, the peak energy production period so far was during bright, cool days in April – not during the recent, triple-digit days of summer. The poor air quality that is more prevalent in summer and high temperatures that affect the reflection surface actually reduce the amount of energy the panels can produce.

Oncor, which provides electricity to the SMU campus, provides rebates to users who offset their energy consumption with electricity produced from solar panels. The rebate SMU received helped reduce the cost of installing the panels, making the installation a more cost-effective choice. Oncor officials believe SMU is the first educational facility to take advantage of the rebate program.

The SMU solar array generated enough green electricity in its first eight months to offset the University’s carbon footprint by 10.7 metric tons – equivalent to planting 252 trees.

Texas has the greatest solar energy generation potential of any state in the country, according to the State Energy Conservation Office, but photovoltaic solar generation has historically been too expensive for use in larger applications.  Research has increased PV efficiency, SECO reports, but a shortage of silicon (the primary material used to convert sunlight into useful energy) has limited the production of PVs and kept the cost of solar production relatively high.

The price is coming down, Paul notes, and he is looking for other sites around campus that may be appropriate for larger solar installations – such as the Dedman Center for Lifetime Sports. “It has a huge flat roof, and lots of consumption,” Paul said. “When solar does come down in price, we can go to much larger systems.”


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