Solar Cells

Question 1

What is the energy transformation of a solar cell?

Answer 1

Light energy is transmitted in parcels called photons. Silicon-based solar cells are less than 20% efficient. This means they transform less than 20% of the incoming light energy into electrical energy. The rest of the light energy into heat energy.

Question 2

How do the silicon-based solar cells?

Answer 2

Contain thin layers of two different materials, each of which is mostly made from silicon. When photons enter one of these materials, their energy is transferred to electrons on the surface of some of the atoms, which causes them to move out and along the junction between the layers. This causes a movement of the electrons around the electrical circuit.

Question 3

Advantages

Answer 3

• Solar cells convert solar energy directly into electrical energy.
• They have no moving parts that can wear out.
• Do not produce greenhouse gases or pollution when operating. - - They provide electrical energy for over 50 years.
• They can be used in remote areas.
• Excess energy can be stored in batteries for later use.
• Many places receive a lot of solar energy.

Question 4

Disadvantages

Answer 4

• variable of light intensity due to cycle between day and night, clouds, shadows, changing angle of incoming sunlight to face the panel, changing position of the sun, dirt, pollutions or other obstructions
• this means that they can not produce a consistent amount of energy
• expensive
• low energy efficiency
• expensive