Question

each group of solar cells is arranged in a rectangle 1.2 mx2.8m.the solar cells are situated in a region where 260w of solar energy is recieved per square m of the cells ,the electric output of each group of solar cells is a current of 2.5 with a potential difference of 86v.calculate teh efficency of the solar cells

Answer 1

What we get is 260 W/m² of solar energy applied to 1.2*2.8=3.36 m² of the area of solar cells. The power received is

$$P_i=3.36·260=873.6\text { W}.$$

We get the electrical power of value

$$P_o=86·2.5=215\text{ W}.$$

Therefore, the efficiency is

$$\eta=\dfrac{P_i}{P_o}=0.25,$$

or 25%. This is a typical efficiency value for solar cells.