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What's next for Solar Power and Green Roofs
What's next for Solar Power and Green Roofs

“If you’re looking for a source of energy, the sun is huge.”

Dr. Carl Wamser, Professor of Chemistry Emeritus at Portland State University, is sitting behind his desk on a particularly tempestuous November afternoon discussing the growing need for clean, renewable energy and how to meet that need. It’s not the kind of day that evokes images of rooftop solar panels, or the shimmering expanses of solar farms. It may be gray outside now, but the sun is on the way and so is the next big leap in solar technology.

According to the U.S. Department of Energy, the amount of solar energy that falls on the earth’s surface in just one hour is more than the amount of energy consumed by the entire human population in one year. Yet, in 2010 solar energy accounted for 0.04 percent of net electricity generated in the U.S. There is no one reason that accounts for the chasm between solar energy utilization and other methods of generating power, but the fact of the matter is that we’ve reached an unsustainable critical mass with our energy consumption that could have dire consequences on the environment and society. Unless, that is, a concerted effort is made to harness more of the sun’s energy for our use.

In the Wamser Lab at PSU, Dr. Wamser and his team are working to revolutionize the way photovoltaic cells capture and convert energy. Currently, the majority of solar panels are silicon-based and imported from China. While these panels are well-engineered, they’re expensive to purchase and install. With grand funding from the National Science Foundation (NSF), Dr. Wamser is trying to answer the question: What’s next after silicon?

“Silicon solar panels are getting cheaper,” Dr. Wamser said, “but they’re still not cheap enough to be effective and feasible in the long run. We’re using lessons we’ve learned from nature to create better and hopefully less expensive, photovoltaic cells. We’re looking at organic solar cells—a thin film of photovoltaic plastic that could be deployed anywhere the sun shines.”

Drawing from nature, Dr. Wamser has developed a synthetic analogue to photosynthesis using organic compounds that are structurally similar to chlorophyll. The process is sometimes referred to as artificial photosynthesis.

“In the long run, I think an organic photovoltaic plastic material would really make sense. If it were cheap enough you could put it on windows, rooftops, and other unused surfaces exposed to the sun.

“One of the statistics people like to quote is: if we took the area that’s been paved in federally numbered highways and build solar cells on a similar scale, we could generate enough electricity to meet all of our needs, including gasoline, heating, and everything else. Why not start on windows and rooftops?”

While working on developing the photovoltaic cell of tomorrow, Dr. Wamser, with the support of a second NSF grant, is researching methods to maximize the efficiency of today’s solar panels integrated with green roofs. A burgeoning trend in cities across the country, a green or living roof, is simply a roof of a building that is partially or completely covered with vegetation. Like photovoltaic cells, green roofs have both environmental and economic benefits.

“We’re looking at the interactions between photovoltaics and green roofs,” Dr. Wamser said. “The basic hypothesis is that plants do better if they have a little shade and are protected from direct sunlight and that silicon photo cells are more efficient when they’re cooler. So the idea is that the solar panels will shade the plants and the plants will help keep the roof cooler, which in turn will benefit the panels. We’re measuring the interactions between the plants and panels to better understand if they add efficiency.”

This coming February, Dr. Wamser, in association with the Oregon Museum of Science and Industry (OMSI) and the NSF, will take his passion for research, chemistry, and solar energy out of the lab and into the public sphere. “Connecting Researchers and Public Audiences” (CRPA) is a NSF funded program that provides researchers the opportunity to present and discuss their work with the public. In the coming months, Dr. Wamser and his team will be working on exhibits, demonstrations, and online content that he will present next summer at OMSI. The CPRA program will allow members of the public to visit OMSI, learn about solar energy and green roofs, and share in the experience of discovery. As a part of the program, Dr. Wamser will also be giving a science pub talk in February.

“The reason we do solar research is because of its immense importance to humankind. I think our energy crisis is one of the most important problems in the world we can address today. The sun completely outweighs any other energy source you can look at. Given the amount of energy it puts out there, we only need to capture and convert a small portion of it. That’s where chemistry comes in: start with light energy and turn it into something useful. That’s what we’re working on.”

Authored by Shaun McGillis
Posted December 17, 2012