8.3 Solar Power

Question 1

How can you extract solar energy from the sun?

Answer 1

Photovoltaic systems or solar active devices.

Question 2

What happens in photovoltaic systems?

Answer 2

These are cells made out of semiconductors. Sunlight incident on each cell reduces a DC current and a DC voltage by a process similar to the photoelectric effect. The currents and voltages are generally small so photovoltaic cella are of limited use except in large arrays.

Question 3

What is the energy conversion in photovoltaic systems?

Answer 3

Solar to electric.

Question 4

What happens in solar active devices?

Answer 4

These are commonly used in many countries to extract thermal energy from sunlight and use it to heat water for domestic use. These simple, cheap collectors are usually put on the roof of a house. A disadvantage is that they tend to be bulky and cover a large area.

Question 5

What are the advantages of solar energy?

Answer 5

Unlimited energy supply
No extraction costs
Clean

Question 6

What are the disadvantages of solar energy?

Answer 6

Works only during the day
Affected by cloudy weather
Low energy density
Requires large area for collectors
High initial costs for photovoltaic systems.