|
|
What contribution can solar energy make to the Northwest's energy needs? That is the question Frank Vignola has been exploring since 1977. Vignola is a
senior research associate in the
University of Oregon physics department and
director of the Solar Radiation Monitoring Laboratory (SRML)."Our work is dedicated to producing the most accurate solar radiation data
possible. In simple terms, we keep track of exactly how much sunlight is coming
our way. Half of our
13 monitoring stations are concentrated in Oregon,
|
And how big a resource might it be? Vignola's research indicates that prime
sites in eastern Oregon could produce four times the region's energy needs, or
the equivalent output of sixty power plants--each with a thousand megawatts of
generating capacity. In the same way that stream flow data are necessary for an accurate
calculation of the productivity and cost-effectiveness of a proposed
hydroelectric dam, accurate solar "flow" data are necessary for planners to
weigh the costs and benefits of adding solar power generation to the region's
energy mix. "Solar energy is not science fiction," Vignola asserts. "Right now, solar
facilities in California with over 350 megawatts of generating capacity are
successfully marketing solar electricity."Vignola is using his massive database of solar radiation measurements to help
other researchers. One project will enable more accurate information to be
extracted from satellite sensing devices. In another, Vignola used the database
to determine the amount of solar energy available to photovoltaic cells mounted
on east-west oriented roofs as compared to those with the
assumed-to-be-superior southern orientation. His calculations show that, in
fact, the difference between the two orientations is less than previously
believed. "The next century will be the beginning of the solar age," Vignola asserts.
"Solar resource assessment is an essential element of the infrastructure that
will bring that age about."
|
There are no gas stations on Mars. So when NASA's Mars rover was tooling
around the surface of the Red Planet, it relied on
photovoltaic (PV) cells to
gather energy from the sun and keep its "tank" on the F side of E. "NASA wasn't concerned about cost with the rover's cells, which were made of
super-efficient but very costly materials," says Dave Cohen, a professor of
physics at the University of Oregon. "Here on earth, where we've got to balance
both efficiency and cost, the number-one contender for a workable PV that could
be mass-produced and have a real effect on our energy needs is a material
called amorphous silicon."
|
Amorphous silicon is cheap, abundant and easily fabricated, says Cohen, who is
playing an important role in a national effort to develop economically viable
PV cells. Fixed on a substrate of glass or stainless-steel foil, a layer of
amorphous silicon one ten-thousandth of an inch thick can efficiently capture
energy from the sun and transform it into usable electricity. But there is a snag. The impressive electrical properties of amorphous silicon
diminish with long-term exposure to light. This "stability problem" is one of
the most serious challenges facing researchers seeking to improve this
technology. Work in Cohen's laboratory is focused on determining the fundamental
mechanisms of this instability and overcoming their limiting effects on solar
cell performance. In addition, he coordinates the research for a nationwide
group of about fourteen scientists (funded through the National Renewable
Energy Laboratory in Golden, Colorado) who experiment with various ways to
overcome the stability problem. When one of these scientists devises a
potential improvement, they often send a test sample to Cohen, who uses his
twenty years of experience with amorphous silicon to analyze its electrical
properties and stability. "PV-produced energy is going to play an increasingly important role as
technological advances make cheap, highly efficient PVs available for both
commercial power generation and home energy needs," Cohen says. "Our work will
continue until those technological advances are achieved."
|
"An architect who is not keeping the sun in mind is an architect who is not
doing his job," says John Reynolds, a University of Oregon professor of
architecture and director of the UO Solar Energy Center. "The sun is a vital
element of any architectural design. It gives you light and heat and, if you do
it right, it will even cool your building."This passionate belief in the importance of "passive solar architecture" has
guided Reynolds's career since he joined the UO architecture faculty in 1967.
Over the years, more than 3,000 students have studied with Reynolds. He teaches
Environmental Control Systems, a course required for all architecture students,
as well as advanced seminars in passive solar heating and cooling. He helped
write Inside Out: Design Procedures for Passive Environmental
Technologies, an influential book inf the field of passive solar
architecture."There are many different ways to address the architectural questions of
heating, cooling, lighting, acoustics, water, and waste," Reynolds says. "In my
classes, I've tried to teach my students that the most elegant and
environmentally integrated path to this end is to make the most of the
principles of passive solar architecture."Two of the most noticeable characteristics of solar buildings are lots of
south-facing glass, to let in the sun's strongest rays, and lots of thermal
mass (a brick wall, for example) behind the glass, to store the sun's energy
for use at night. Reynolds has recently studied the solar dynamics of courtyard architecture and
the cooling--and pleasant aesthetic--effect it can provide a building.
|
"The concept of wrapping each building around a garden, as is common in Spain,
for example, is the opposite of the pattern of the North American residential
neighborhood, where the garden is wrapped around the building," he observes.His next project is compiling the information and insights he gathered during
his courtyard research project into a book.The American Solar Energy Society presented Reynolds with its 1997 Passive
Pioneer Award for his work in the field of passive solar energy.For additional information about solar-related work at the UO and around the
world, visit the student-operated UO Solar Information Center on the World
Wide Web at http://darkwing.uoregon.edu/~sic/.