Year 9 Science · Unit 3 · Lesson 15
Challenge Worksheet
Learning Goals
Compare two
Complete the comparison table for four energy storage technologies. Use H (high/good), M (medium), or L (low/poor) where a value is not given. Some cells have been filled in to get you started.
| Criterion | Battery (Li-ion) | Pumped Hydro | Hydrogen | Compressed Air |
|---|---|---|---|---|
| Cost per kWh stored | ~$400/kWh | ~$500/kWh | ~$150/kWh | |
| Response speed | Milliseconds | Minutes | ||
| Duration of storage | 6–100 hours | 2–24 hours | ||
| Location requirements | Flexible, any site | Requires underground cavern | ||
| Round-trip efficiency | 85–95% | 30–45% |
Design challenge
You are advising an Australian town of 5 000 people called Sunvale. The town has abundant solar energy but no rivers or mountains nearby for pumped hydro. The local council has a limited budget and wants reliable 24/7 electricity supply from renewable sources. Design an energy storage strategy using at least two technologies. Justify every choice against the comparison criteria from the Warm Up.
(a) Which two storage technologies would you recommend for Sunvale? Explain why each is suitable given the town's constraints (no rivers, limited budget, abundant solar).
(b) Describe how your two chosen technologies would work together across a 24-hour day, when would each be used and why?
(c) What is the biggest remaining challenge for your plan, and what trade-off does the council have to accept?
Wrap Up
In one sentence, what was the main idea of this lesson?