Maximum Efficiency of a Solar-energy Panel

alweltz

1. The problem statement, all variables and given/known data

The maximum efficiency of a solar-energy panel in converting solar energy into useful electrical energy is currently about 12 percent. In a region such as the southwestern United States the solar intensity reaching Earth's surface is about 1.0 kW/m2 on average during the day. Estimate the area that would have to be covered by solar panels in order to supply the energy requirements of the United States (approximately 5.00 1020 J/y).

2. Relevant equations

(5.00 x 10^20 J/y) X (1/365 y/d) [eq a.]

A= (L) x (w) [eq b.]

(1.0 kW/m^2) x (.12) [eq c.]

3. The attempt at a solution

I have tried multiplying [eq c.] by [eq. a]. Then, take that answer and multiply it by itself to get m^2.

OmCheeto

Gold Member
1. The problem statement, all variables and given/known data

The maximum efficiency of a solar-energy panel in converting solar energy into useful electrical energy is currently about 12 percent. In a region such as the southwestern United States the solar intensity reaching Earth's surface is about 1.0 kW/m2 on average during the day. Estimate the area that would have to be covered by solar panels in order to supply the energy requirements of the United States (approximately 5.00 1020 J/y).

2. Relevant equations

(5.00 x 10^20 J/y) X (1/365 y/d) [eq a.]

A= (L) x (w) [eq b.]

(1.0 kW/m^2) x (.12) [eq c.]

3. The attempt at a solution

I have tried multiplying [eq c.] by [eq. a]. Then, take that answer and multiply it by itself to get m^2.
Do you know how to convert Joules per unit time to watts?

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