1. Solar Energy- Photovoltaics (solar cells)

2. Photovoltaics generate constant electricity– direct current
Electrical terms:
Voltage (difference) (V): Amount of energy per charge required to move charge around a circuit
Current (I): Moving charge
Buildings are powered by alternating current. An inverter is needed to use a photovoltaic to power appliances in the home to convert to alternating current

3. Electric Circuits
                                                                         
An electric circuit is often compared to a pipe system

4. Light Intensity And Photovoltaics
Light Intensity: a measure of the energy of the light
The higher the intensity, the more photons generated, hence, greater current and voltage

5. Light wavelength and photovoltaics
Speed of light c= frequency (f)* wavelength (l)
c=f l =3 ×108 m/s
Frequency f: # of cycles per second that pass a given point
Wavelength l : Length of a single cycle of the wave
Good website on waves
Good website on EM waves

6. Photovoltaics: Amount of current/voltage depends on wavelength
Silicon: Best at infrared wavelengths (l=1mm)
Spectral response: he ratio of the current generated by the solar cell to the power incident on the solar cell .