The International Space Station (ISS) has several solar panels called wings - Edexcel - GCSE Physics - Question 1 - 2015 - Paper 1

To calculate the percentage efficiency of the wing, we first need to find the total energy incident on the wing from the Sun:

1. The energy incident on the wing = 5 times the useful energy available from one wing.

   Total Incident Energy = 5 × 34.3 kJ = 171.5 kJ.

2. The formula for percentage efficiency is given by: $\text{Efficiency} = \left( \frac{\text{Useful Energy Output}}{\text{Total Energy Input}} \right) \times 100$

3. Now substituting the values: $\text{Efficiency} = \left( \frac{34.3}{171.5} \right) \times 100 \approx 20\%$.

Thus, the percentage efficiency of the wing is 20%.