Year 9 Science · Unit 3 · Lesson 16
Challenge Worksheet
Learning Goals
1. (a) Nuclear power is often described as “low-carbon, but not emission-free”. Explain what this means. (b) What do the terms baseload, peaking and intermittent mean for a source of electricity? Give one example of each. (c) Name the organisation that runs the National Electricity Market, and describe one of its jobs.
Data: a solar farm and a wind farm in the same region
A solar farm and a wind farm in the same region of south-eastern Australia feed the same substation. Table 1 shows the electricity each one produced in six months of one year.
| Month | Solar farm | Wind farm | Both farms together |
|---|---|---|---|
| January | 1,100 | 1,300 | |
| March | 900 | 1,400 | |
| May | 600 | 1,800 | |
| July | 500 | 2,000 | |
| September | 800 | 1,700 | |
| November | 1,050 | 1,250 |
Source: sample values for this worksheet.
2. Complete the last column of Table 1. Then find the range (highest value minus lowest value) for the solar farm, for the wind farm, and for both farms together.
Range, solar farm MWh
Range, wind farm MWh
Range, both together MWh
3. What percentage of its January output did the solar farm produce in July? Round to the nearest whole number. Suggest why its output falls in winter.
July as a share of January %
4. A planner says: “Building both farms gives a steadier supply across the year than building either one alone.” Use your ranges to decide whether the data supports this. Then describe one thing that monthly totals cannot tell you about whether the region’s lights will stay on every night.
Find the mistakes: a student’s essay
“Australia’s electricity comes from many different sources. Wind power is always available, 24 hours a day, because Australia is such a large and windy continent. Nuclear power stations release large amounts of CO₂ while they operate. Australia stores surplus renewable energy using pumped hydro, which stores the energy as chemical energy in water. The National Electricity Market (NEM) covers all of Australia, including Western Australia and the Northern Territory, so every home is connected to the same grid.”
5. The essay contains four scientific errors. Quote each error, and write a correct version.
| Error | What the student wrote | Correct version |
|---|---|---|
| 1 | ||
| 2 | ||
| 3 | ||
| 4 |
Someone claims…
“Batteries alone will solve Australia’s energy storage problem. We just need to build enough of them.”
6. Evaluate this claim. Consider how long energy needs to be stored for (hours, days or seasons), use Table 1, and propose the mix of storage technologies you would choose instead.