Solar Energy
Solar Energy
Types of solar energy
Solar Thermal
Radiant energy to heat
Very similar to a coal electricity plant
Solar Photovoltaic
Radiant energy directly to electricity using semiconductor technology
Solar can be scaled from large to small amounts of generation
The journey of a photon
Created in the core of the sun by nuclear fusion reaction
Millions of years to bounce out to surface of sun
Zips to earth in about 8 minutes
Passes through the atmosphere
Strikes a solar panel and dislodges an electron in the PV panel
Electron is collected and delivered to the grid
Solar radiation
Conversion of mass energy to radiation
Converts hydrogen to helium
Solar radiation
Solar energy
Peak solar power about 1000 watts per square meter
Solar power is usually measured for this level of sunlight
However, sun is not always this bright
Our sunniest locations get about 5.5 kWh per square meter per day of sun energy
Electromagnetic Spectrum
Blackbody Spectrum
Solar Photovoltaic
Converts sunlight directly to electricity
Commercially available panels have 15% -- 20% efficiency of solar
energy in to electrical energy out
Photovoltaic electricity plants
Agua Caliente
Highest power photovoltaic power facility in 2013
Yuma, Arizona
397 MW peak production
25 year power purchase agreement
Agua Caliente Data
Agua Caliente Monthly Production Data
Solar thermal plants
Parabola
A parabola is the shape that reflects parallel lines to a point. Since the sun's rays are essentially parallel, this focuses the sun to a point.
Concentrating solar power trough
We heat oil along large parabolic mirrors.
SEGS
Solar Energy Generating Systems
First solar thermal plants
Daggett, CA
Built in 1984 and 1985
Ivanpah
377 MW
Concentrating solar thermal power towers
Near Las Vegas, Nevada
No thermal storage
Natural gas backup
Ivanpah solar plant
Solar power tower
Solar Thermal
Advantages
Uses well established thermal electricity technology
Disadvantages
Needs water, scarce in sunny climates
Developing world solar
Phone charging
Water pumping
Lighting
Solar Lantern
Solar Installed Capacity
What scale is needed?
World primary energy consumption approximately 500 EJ
Power = Energy / Time
Joules / seconds = Watts
Photovoltaic learning curve
Solar Energy
Approximately 1000 watts per square meter on the surface of the earth
at peak
170 watts per square meter average insolation
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