solar energy types of generators irradiance insolation how solar cells work
TRANSCRIPT
Solar EnergyTypes of Generators
Irradiance
Insolation
How Solar Cells work
Topics Part 1
Types of Solar Power Generators Irradiance Inverse Square Law
Part 2 Path of Sun: Seasonal and daily Effective cross section Insolation Rate
Part 3 How Solar Cells work Power & IV Curves Maximum Power Point Efficiency
Part 1:Types of Solar Power Generators
Passive Solar heat collectors Rooftop solar water heaters
Solar heat collectors – Steam Turbines Parabolic Troughs Thermal Towers Other Solar Concentrators
Photovoltaic Panels Silicon, crystalline, thin film, organic dyes
Solar Water Heaters
Solar-Steam Generators
Solar-Steam Generators
Parabolic Trough
Ausra: 177 MW
Carizzo Plain
Thermal Tower
Mojave
Other Solar Concentrators
Photovoltaics
PG&E Carizzo Plain
Topaz 550 MW & High Plains Ranch 250 MW
CalExpo Solar Park
IrradianceVisible light only
FV = luminous flux of the source (lumens)
EV = Illuminance of an object illuminated by FV at a distance d ( lm/m2 = lux)
EV = FV / 4d2
ex: 800 lumen bulb at 2 meters distance EV = (800 lm / 4(2m)2 = 16 lx
All electromagnetic radiation:
Visible efficacy of an Incandescent light: =17 lm / W
FR = Radiant Flux of the source ( W ) FR = FV /
ER = Irradiance of an object illuminated by FR at a distance d ( W/m2 )
ER = FV / (4d2 ) = EV /
Example:
An 800 lumen bulb at 2 meter distance
ER = EV / = 16 lx / 17 lm/W = 0.94 W/m2
Inverse Square Law
2
2
1
2
2
1
d
dEE
Irradiance (E) is inversely proportional to the square of the distance (d) from the source
Part 2Path of Sun:Seasonal & Daily
Effective Area
Insolation RateTop of the atmosphere:
Solar constant =1366 W/m2
Peak Surface Insolation:
Clear sky, summer, noon =1000 W/m2
Average Surface Insolation:
Clear sky, year round, all day = 250 W/m2
Typical Insolation:
Paso Robles, Average weather, all day avg
Summer: 6 kWh / m2 / day
Winter: 3 kWh / m2 / day
Part 3:PhotovoltaicsHow Solar Cells work
Power & IV Curves
Maximum Power Point
Efficiency