Question

The value of concentration ratio of a flat plate collector is

• A. 1
• B. 10
• C. 100
• D. 1000

Hint:

Flat plate collector: $C = 1$.
Parabolic trough: $C = 10 - 100$.
Parabolic dish Solar tower: $C = 100 - 1000+$.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The concentration ratio (\(C\)) of a solar collector is defined as the ratio of the effective solar aperture area intercepting sunlight to the surface area of the absorbing receiver.
Key Formula or Approach:
\[ C = \frac{A_{\text{aperture}}}{A_{\text{absorber}}} \]

Step 2: Detailed Explanation:
In a non-concentrating solar flat-plate collector, the entire flat transparent glass cover (aperture) directly admits sunlight onto an absorber plate of the exact same surface area.
Because there are no focusing mirrors, parabolic troughs, or lenses to concentrate the incident radiation:
\[ A_{\text{aperture}} = A_{\text{absorber}} \implies C = \frac{A_{\text{absorber}}}{A_{\text{absorber}}} = 1 \]
In contrast, concentrating collectors (parabolic troughs, parabolic dishes, central receivers) achieve concentration ratios ranging from 10 to over 1000.

Step 3: Final Answer:
Therefore, the concentration ratio of a flat plate collector is 1, matching option (A).