SOLAR PV

Question 1

Definition of Photovoltaics and its benefits.

Answer 1

Directly converts light into electricity.

Silent, no maintenance, no fuel, no emissions
Low cost option for remote applications.

Question 2

Typical radiation value

Answer 2

1.353 kW/m2

Question 3

Solar radiation is either _______,________ or _________

Answer 3

reflected, transmitted or absorbed

Question 4

What percentage of solar makes it to ground level? What percentage of solar is diffused?

Answer 4

70%
7%

Question 5

Ratio of Direct solar irradiance:Diffuse components

Answer 5

90%:10%

Question 6

Formula for direct irradiance. and diffuse irradiance.

Answer 6

Idir=1.353(0.7^(1/cos@))^0.678

Idif=0.1Idir

Question 7

formula for air mass

Answer 7

1/cos@

Question 8

Define Band gap.

Answer 8

Energy between the valence band (electron bound to atom) and the conduction band (electron free to move between atoms).

Question 9

Formula for Band gap

Answer 9

hf=hc/lamda

f- frequency
lamda- wavelength
c- speed of light
h- planks constant

Question 10

Band gap of silicon in eV

Answer 10

1.12eV

Question 11

What effect does wavelength have on energy produced

Answer 11

Shorter yields a higher efficiency

Question 12

wavelength>1,100nm means?????

Answer 12

insufficient energy to promote electron

Question 13

wavelength<1100nm more energy than required to promote electron

Answer 13

more energy than required to promote an electron

Question 14

Max efficiency for a 1.34eV band gap

Answer 14

33.7%

Question 15

Describe a PN Junction Circuit.

Answer 15

Heart of a PV cell is interface between two different types of semiconductor (p-type and n-type). Electron travels through n-type to metal contacts on surface.