6.23 A family uses 8 kW of power.

(a) Direct solar energy is incident on the horizontal surface at an average rate of 200 W per square meter. If 20% of this energy can be converted to useful electrical energy, how large an area is needed to supply 8 kW?

(b) Compare this area to that of the roof of a typical house.

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Payal Gupta | Contributor-Level 10

9 months ago

6.23 Power used by the family = 8 kW = 8000 W

(a) Solar energy received = 200 W/ $m^{2}$

Percentage conversion of Solar energy to Electrical energy = 20%

If the area required is A then 0.2 $* A * 200 = 8000$

A = 200 $m^{2}$ . The comparable roof size is 14.14 X 14.14 m

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