Calculate the power per square meter reaching Earth\'s upper atmosphere from the

Question

Calculate the power per square meter reaching Earth's upper atmosphere from the Sun. (Take the power output of the Sun to be 3. 86xl026 W. ) Part of this is absorbed and reflected by the atmosphere, so that a maximum of 0. 88 kW/m2 reaches Earth's surface. Calculate the area in km2 of solar energy collectors needed to replace an electric power plant that generates 600 MW if the collectors convert an average of 2. 00% of the maximum power into electricity. (This small conversion efficiency is due to the devices themselves, and the fact that the sun is directly overhead only briefly. ) With the same assumptions, what area would be needed to meet the United States' energy needs (1. 05xl0^20 J)? (The energy consumption value is from 2006. ) With the same assumptions, what area would be needed to meet China's energy needs (?. ????19 J)? (The energy consumption value is from 2006. )

Explanation / Answer

a)

radius of the earth=1.5*10^11 m

power output of the sun=3.86*10^26 w

intensity at the earth surface

I=p/(4*pi*r^2)

I=3.86*10^26 w/(4*pi*(1.5*10^11)^2)

I=1365.19 w/m^2

b)

electric power is the 2% of the maximum power

p=0.02*Imax*A

A=p/(0.02*Imax)

=600 w/(0.02*880)

=34 km^2

c)

electric power is the 2% of the maximum power

p=0.02*Imax*A

A=p/(0.02*Imax)

=1.05*10^20/(0.02*880)

=5.965*10^18 Km^2

d)

A=p/(0.02*Imax)

=6.3*10^19/(0.02*880)

=3.579*10^18 Km^2

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.