The minimum collector area is 1.412 m2 (rounded to 3 decimal places)
Explanation:
Stepwise procedure-
Total solar radiation falling /unit area= 850 W/m2
Given= Only 20% of the energy is collected
Need= 240 W
The Minimum surface area of collector=?
Let the minimum surface area be “x” m2
Total solar radiation falling = radiation /unit area* total area
= x*850 W/m2
Total solar radiation utilised = (20/100) *x*850 (given only 20% is utilised)
Since the need is 240 W
Hence the total solar radiation utilised= energy needed
Thus 240 = (x*850)/5
x = (240*5)/850
The minimum collector area is “x” =1.412 m2
