Year 9 Science · Unit 3 · Lesson 13

Non-Renewable Energy Sources

Challenge Worksheet

Name

Date

Class

Learning Goals

Compare nuclear, coal and gas power using lesson data.
Find and correct errors in a power station efficiency calculation.
Evaluate a claim that new gas power stations are better than solar and wind.

Warm Up

1. Describe the energy transformation chain in a nuclear power station. How is it different from the chain in a coal-fired power station?

Recall 2 marks

Your Turn

2. Complete the table using what you learned in the lesson.

Apply 4 marks

Feature	Nuclear	Coal	Natural gas
CO₂ released while generating
Main waste product
Typical efficiency (%)
Used to generate electricity in Australia?

Find the mistakes: a student’s calculation

Question. A power station burns 200 tonnes of black coal each hour. The coal holds 25 MJ of chemical energy per kilogram. The station generates 450 MW. Calculate its efficiency.

Student’s answer. Energy in = 200 × 25 = 5,000 MJ. Energy out = 450 MJ. Efficiency = 5,000 ÷ 450 × 100 = 1,111%.

3. The student made three errors. Describe each error, then calculate the correct efficiency. Show your working.

Analyse 4 marks

Correct efficiency %

Go Deeper

Data: a year of electricity for a regional city

A regional city uses 50,000,000 kWh of electricity a year. These are the lesson’s values for the carbon dioxide released for each kWh of electricity.

Table 1. CO₂ released for each kWh of electricity

Source	CO₂ for each kWh (kg)	CO₂ for the city in a year (tonnes)
Coal	0.85
Gas, combined-cycle	0.40
Nuclear	near zero	near zero
Solar or wind	near zero	near zero

Source: values from Lesson 13.

4. Complete Table 1. Then calculate the percentage by which switching the city from coal to gas would cut its CO₂.

Apply 3 marks

Coal t

Gas t

Cut %

5. Nuclear power releases almost no CO₂ while generating, and Australia has large uranium reserves, yet it has no nuclear power stations. Give two reasons from the lesson, and say whether each reason is scientific, economic or political.

Analyse 2 marks

Show What You Know

Someone claims…

“Australia should build new gas power stations instead of solar and wind farms. Gas is much cleaner than coal, it is efficient, and unlike solar it works at night.”

6. Evaluate this claim. Give at least one argument for it and at least two against it, using evidence from this sheet and the lesson.

Analyse 6 marks