A family uses 8kW of power. (a) Direct solar energy is incident on the horizontal surface at an average rate of 200 W per square metre. If `20%` of this energy can be converted to useful electrical energy, how large an area is needed to supply 8kW? (a) Compare this area to that of the roof of a typical house.

Explanation

To solve the problem step by step, we will follow the given information and perform the necessary calculations.

### Step 1: Understand the given data
- The family uses power: \( P = 8 \text{ kW} = 8000 \text{ W} \)
- Solar energy incident on the surface: \( E = 200 \text{ W/m}^2 \)
- Efficiency of conversion to electrical energy: \( \text{Efficiency} = 20\% = 0.20 \)

### Step 2: Calculate the electrical power generated per square meter
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