Solar Basics

When was the silicon solar cell invented?

• 1950's

• 1940's

• 1970's

What was the typical efficiency of solar cells before the invention of silicon solar cells?

• Around 1%

• Around 3%

• Around 10%

• Around 20%

Calculate the power output of a 0.5 m^2 solar cell with an efficiency of 1% assuming 1000 W/m^2 of illumination.

• 10

• 5

• 2

• 1

Calculate the solar constant at Mars

We know the luminosity of the sun to be 3.828 \cdot 10^{26} W

3.828⋅1026

W, and the distance from the Sun to Mars is 1.524 AU or 2.280 \cdot 10^{11}m

2.280⋅1011

m.

We have just learned how to calculate the solar constant (the radiation power per square meter or irradiance outside the Earth’s atmosphere), by dividing the luminosity of the sun with the surface area of a sphere of radius 1 AU. Now we want the solar constant for Mars at 1.524 AU, so we will need to calculate the surface area of the sphere with the Sun / Mars distance as the radius and then calculate the the ratio between the luminosity and this area.

• 586

• 685

• 20

• 100

Calculate the efficiency of the Juno solar cells

The space probe Juno is fitted with the largest solar array wings ever deployed on a planetary probe measuring 72 square meters generating about 486 W when Juno is orbiting Jupiter.

You must calculate the efficiency of the solar cells on Juno given that distance to the sun of 5.25 AU (5.25 AU = 7.854 x 10^{11}m

7.854⋅1011

m) and the illuminosity of the sun (3.828 \cdot 10^{26} W

3.828⋅1026

W).

• 32

• 14

• 3

• 1

Select the correct statement(s) from the list below

• The first silicon solar array was installed in 1884 on a New York rooftop

• Werner von Siemens is credited as the inventor of the selenium solar cell

• Silicon solar cells where invented in the 1950s at Bell labs

Calculate the power output of a 1m^2

solar cell with an efficiency of 0.5%

0.5% assuming 1000W/m^2

of illumination

• 1

• 2

• 5

• 10

Calculate the efficiency of a 0.5 m^2 solar panel producing 20 W. Assume that the power input is 500W

• 2

• 4

• 3

• 100

Select the correct formula to calculate the power output of a solar cell

Pout is the power output of the solar cell in watts

η is the efficiency

A is the area of the solar cell in square meters

σ is the solar constant in watts per square meter

• Pout ​=σ⋅η⋅A

• Pout=(σ⋅η) / A

  ​

• Pout ​= (η⋅A) / σ

  ​

We want to design a mission to Saturn with a space probe delivering the power. The space probe has been designed to operate with a low power consumption of 150 W, and we have access to 30% efficient GaAs solar panels.

How large of an area do we need to supply the solar panels when we know the distance to Saturn is 9.539 AU or1.427·10^12 m? The luminosity of the sun is 3.828·10^26 W.

• 23

• 33

• 50

• 12