If the efficiency of the panel is 30%, determine the power input into the photovoltaic plate. Above the earth's atmosphere, the solar constant is 1.4 kWm⁻². However, only 40% of this power per unit a

Given: $P_{out} = 50.0 \text{ W}$, $\eta = 30\% = 0.30$

$$P_{in} = \frac{50.0 \text{ W}}{0.30}$$

$$P_{in} = 166.666... \text{ W}$$

The power input into the photovoltaic plate is approximately $\boxed{\text{167 W}}$

ii) Above the earth's atmosphere, the solar constant is $1.4 \text{ kWm}^{-2}$. However, only 40% of this power per unit area reaches the earth. Estimate the surface area of the panel in figure 10.

Solar constant $(S) = 1.4 \text{ kWm}^{-2} = 1400 \text{ Wm}^{-2}$
Intensity at Earth's surface $(I_{earth}) = 40\% \text{ of } S$

$$I_{earth} = 0.40 \times 1400 \text{ Wm}^{-2}$$ $$I_{earth} = 560 \text{ Wm}^{-2}$$

Using $P_{in} \approx 166.67 \text{ W}$ from part (i).

$$A = \frac{166.67 \text{ W}}{560 \text{ Wm}^{-2}}$$

$$A = 0.297625 \text{ m}^2$$

The estimated surface area of the panel is approximately $\boxed{\text{0.298 m}^2}$

iii) Explain why solar energy is referred to as renewable source energy.

Solar energy is considered a renewable energy source because it originates from the sun, which provides a virtually inexhaustible supply of energy on a human timescale. The sun continuously emits vast amounts of energy, and its supply is not depleted by human use, unlike finite fossil fuels.

i) What is the ozone layer?

The ozone layer is a region within the Earth's stratosphere that contains a relatively high concentration of ozone (O₃) molecules. Its crucial function is to absorb most of the Sun's harmful ultraviolet (UV) radiation, preventing it from reaching the Earth's surface and protecting living organisms from its damaging effects.