Portland State Magazine Winter 2008

David Sailor, mechanical engineering faculty, has developed software that analyzes the energy savings that a green roof, such as this one on The Broadway on the PSU campus, can provide a building. as much as seven degrees hotter than the surrounding countryside. And all the buildings and roads create a massive heat srockpile chat radiates for hours after the sun sets. Scientists say cities are heat islands and chat's where David Sailor, associate professor of mechanical engineering, steps in. Sailor studies how much heat is gained or lost by specific activities or items-say, driving ro work versus stay– ing home with the air conditioner on. Or planting 100,000 trees versus install– ing 1,000 green roofs. Sailor hopes his data will help people understand how ro turn the urban hear island's temperature down . And it has. Until Sailor's research, architects and builders could nor evaluate precisely whether a green roof would benefit their project. Did a layer of soil and plants allow a building to absorb less hear and therefore use less air conditioning? Us– ing software developed by Sailor, they can now figure it out. Sailor is also part of a PSU faculty ream mapping Portland and Housron, Texas, block-by-block ro determine the precise air temperature coming from asphalt roads and from shady lanes. When he's done, cities will be able to verify whetl1er planting 100,000 trees, for example, will really pay off in lower remperatures. The project is also surveying residents co determine what they actually do when they hear an air quality alert, which will help governments determine how best to design effective advisory systems. For Sailor, cooling off the island all starts with the data. "Understanding the causes of the urban heat island," he says, "is the first step in knowing what ro change." Learning from leaves If you lived inside a leaf, you'd have all the free energy you could want. Sound a little crazy? Scientists have already developed prototypes. The method is called artificial phoro– synchesis, and Carl Wamser, professor of chemistry, believes we'll see commercial– ly viable applications within the decade. A leaf's green chlorophyll membrane absorbs sunlight and uses chat solar energy to push electrons chat exist in the Carl Wamser, professor of chemistry, is working on synthetic membranes that-like leaves-can convert sunlight into electricity. membrane into the plane cell in a form the plant can use for energy. Wamser and about 50 ochers research– ers worldwide are developing synthetic membranes using a similar process co convert sunlight into electricity-on a scale that one day could be used in homes and skyscrapers. To dare, scientists have created arti– ficial membranes char work; however, these prototypes are only about five percent efficient (compared ro silicon cells, which can be 10 ro 15 percent efficient). Bur Wamser is optimistic chat current research-including his-will one day result in membranes so efficient, durable, and chin they could be embed– ded in, say, roof shingles or siding ro power a building. "Scientists like ro point our," says Wamser, "char in one hour the amount of sunlight char falls on the Earth is more than all the energy used worldwide in an entire year." Wamser, a longtime solar power enthusiast, is also working with more traditional solar panels. Using a $144,000 U.S. Department of Energy grant, he'll be testing nine configurations of solar panels. The panels are set ro begin operation on rop of Cramer Hall in summer 2008. ■ Melissa Steineger, a Portlandfreelance writer, wrote the article '11 Different Casualty Count" in thefoll 2007 Pordand Scace Magazine. WINTER 2008 PORTLAND STATE MAGAZINE 11