Post on 23-Feb-2017
transcript
PV Mirror A High-Efficiency Solar Module
Wyatt Taylor
Introduction• Sophomore in Mechanical Engineering• From Kingman, Arizona• Passionate about finding alternative energy
resources• Began working at the Steward Observatory in
October 2015
Steward Observatory Solar Lab
Research Assistants:
Principal Investigator:
Professor Roger Angel
Ph.D. Student: Justin Hyatt
JJ Mrkonich
Lennon Reinhart
Wyatt Taylor
Our Project• Combining traditional Photovoltaic (PV) cells
with Concentrated Solar Power (CSP).• Funded by the Advanced Research Projects
Agency of the US Department of Energy (ARPA-E).• Partner university – Arizona State University• Project Head: Professor Zachary Holman
• 3 year project (currently completing the second year).• 3 prototype stages.
The Two Technologies: PV Cells• Photovoltaic solar cells are
found in private and commercial use.• Through the photovoltaic
effect, semiconductor materials convert solar energy into direct current electricity. • The only issue, some of the
light cannot be absorbed, and reflects off the surface. Current efficiency ratings range from 8-17%.
The Two Technologies: CSP• Concentrated Solar Power is the method of reflecting sunlight to a particular point and harnessing the heat energy using a thermal absorber.• For our applications, we
are focusing on trough geometry.
Parabolic Trough Mirrors at Solana Generating Station
(Gila Bend, AZ)
HeliostatIVANPAH Solar Electric Generating Station (San Bernardino, CA) 392
MW
Bringing the Two Together• In order to increase
overall efficiency, we combine the two methods.• Once sunlight hits the PV
mirror, the useable wavelengths are absorbed, the rest are reflected.• This is done using a
dichroic mirror film, specialized for separating the sunlight.
First Stage: Slumping the Glass
• A piece of glass, placed on a stainless steel mold, is heated to around 1400°F.• The glass is allowed to relax as it cools,
therefore taking on the mold’s shape.• From here the curvature and line focus are
tested .
Second Stage: Testing the Glass
• Using a fabricated vice setup, a laser is focused onto the glass, which reflects the light onto a screen.• Because of the model’s shape, all the reflected
light condenses into a single line focus at the radius of curvature (approx. 1.7 meters).• This must be done in complete darkness in
order to accurately measure the shape error.
Third Stage: Cell Placement and Lamination
• After the glass passes inspection, PV cells are installed and it is laminated with the dichroic film. • The model is then
tested again for its shape error.
Solar Testing• After the model is
completely finished, it can be tested for power efficiency.• Using a solar tracker
with azimuth and elevation movement, we are able to accurately track the sun in order to achieve maximum power output.
Solar Testing• In order to attach the models to the tracker,
we built a mounting cage equipped with removable tip-tilt stages.
Solar Testing• While focused on the sun,
the power generated by the PV cells is measured.• The reflected light is directed
to a calorimeter at the line focus.
The Calorimeter• The calorimeter is essentially a piece of bent
copper sheeting with a copper pipe attached to both sides.• Thermistors measure the inlet and outlet
temperature of water flowing through the copper piping.
Next Steps• As the second year ends, and the third and final
year begins, we will scale up to a third prototype.• Although the dimensions are still undetermined, it
will at least be a full scale tracker model (approx. 5ft square).
Results
Results
Results
Results• While the typical PV cell has around 8-17%
efficiency, our models, once full scale in prototype 3 will have approximately 32-37% efficiency.• This is only using standard solar cells,
therefore we could theoretically break records if we included more efficient ones.• This would defeat our mission of maintaining
an economical prospective on the project.
Impact• Combining PV cells with CSP, creates great
opportunities in the solar industry.• This method is more economical and user
friendly to industry members.• Once installed, these modules will easily be
able to be replaced.• We hope our project is taking another step,
along with the many other research groups, towards a brighter, cleaner, and more sustainable future.
Questions?