Transcript Thermal and PV System Lauren Masseria Jenny Bishop Bryan Picard

Thermal and PV System
Lauren Masseria
Jenny Bishop
Bryan Picard
Solar Photovoltaic
Photo=light Voltaic=electricity
The conversion of solar energy
directly into electricity
Brief History
• Discovery credited to French physicist Edmund
Becquerel in 1839
– ‘Wet Cell’ Battery
• 1883 the first PV cell was created
• 1950 at the Bell Laboratory, New Jersey
– Research on silicon semiconductors
• 1960’s-70’s Orbiting satellite usage
• 1970’s Rise in residential and commercial usage
– Energy crisis
• 1980’s Consumer electronic devices
Why Solar?
• Reliable
• Long term cost benefits
• Environmentally friendly
• Remote Locations (grid unavailability)
• State, federal and private incentives
• Socially responsible
• Positive public image
Panels & Cells
• A cell consists of sliced up crystals, connected with wire,
and placed in a module
• Life expectancy = over 30 years
• There is nothing exhausted in
the silicon cells, and theoretically,
if well packaged and protected
from moisture they could produce
electricity indefinitely.
• PV cells are a junction between two thin layers of
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dissimilar semi-conduction materials known as ‘p’ and ‘n’
type semi conductors
Most cells made from silicon, a semiconductor, and the
second most abundant element in the earth’s crust
Sets up an electric field when joined
Photons (sun energy) hit this electric field and transfer
energy to the p and n semi conductors creating a reverse
electric field and an electric current
Types of Cells
Three types of PV cells
Monocrystalline
Polycrystalline
Amorphous
Monocrystalline
Silicon with a single crystal lattice structure
with no impurities and virtually no defects
most efficient at 16%
– most expensive
– longest life span
Polycrystalline
Consists of many small grains of connected
monocrystalline silicon
– 15% efficiency
– typically less expensive
than monocrystalline
Amorphous / Thin Film
Silicon are much less ordered than in the mono
and polycrystalline cells
– 8% efficiency
– least expensive
– Most flexible models, ex rolls
– Take the most space
– Are being phased out