Year 9 Science · Unit 3 · Lesson 15

Energy Storage Technologies

Foundation Worksheet

Name

Date

Class

Learning Goals

Match storage technologies to the way each one stores energy.
Calculate how long a storage system can run, using hours = MWh ÷ MW.
Explain why storage is essential for a grid that runs on renewables.

Warm Up

Sort it: which storage technology?

Write each description in the correct box. Each box gets two descriptions.

The Hornsdale Power Reserve in South Australia Stores gravitational potential energy in water held high up Electrolysis splits water to make a gas that is stored Air is squeezed into an underground cavern Lithium-ion cells store chemical energy Snowy 2.0 pumps water uphill when electricity is cheap A heavy wheel spins very fast to store kinetic energy Green hydrogen is kept in tanks for weeks

Battery

Pumped hydro

Hydrogen

Compressed air or flywheel

True or false? Fix the false ones

Circle T or F. If a statement is false, correct it on the line.

While a lithium-ion battery is charging, it changes chemical energy into electrical energy.

Correct it:

Battery storage can respond to a sudden change in grid demand within milliseconds.

Correct it:

The Hornsdale Power Reserve, the “big battery”, is in Victoria.

Correct it:

Green hydrogen is made by burning coal with oxygen.

Correct it:

Pumped hydro can keep supplying power for much longer than a typical lithium-ion battery.

Correct it:

1. Pumped hydro is often called a “giant battery”. What does it have in common with a battery, and how is it different?

Recall 2 marks

Your Turn

Real-world context: the Hornsdale Power Reserve

The Hornsdale Power Reserve, in the Mid North of South Australia, can supply up to 150 MW and stores up to 194 MWh.

Source: “Hornsdale Power Reserve”, Wikipedia.

2. If it starts full, how long can the Hornsdale battery supply its full 150 MW? Use hours = energy stored (MWh) ÷ power (MW). Give your answer in hours and in minutes.

Apply 3 marks

Time hours

Time minutes

3. The lesson says Hornsdale’s main job is not to power the state overnight. Use your answer to Question 2 to explain what its job is instead.

Apply 2 marks

Go Deeper

Table 1. Large storage projects in Australia that were built, being built or planned at the end of 2023

Project	Type	Power (MW)	Energy stored (MWh)	Hours at full power
Riverina Energy Storage System	Battery	150	300	2.0
Kidston	Pumped hydro	250	2,000
Waratah Super Battery	Battery	850	1,680
Silver City, Broken Hill	Compressed air	200	1,600
Melbourne Renewable Energy Hub	Battery	600	1,600

Source: project sizes from the storage and hydro sections of the Clean Energy Council’s 2024 annual report on the industry (Clean Energy Australia Report 2024).

4. Work out how many hours each project can run at full power, to one decimal place. Riverina is done for you: 300 ÷ 150 = 2.0 hours.

Apply 2 marks

5. Describe the pattern in the last column for the batteries compared with the other two types. Which two projects in Table 1 could keep supplying power for longest on a windless night, and why do they tie?

Analyse 3 marks

Show What You Know

6. At 6 pm in a suburb full of rooftop solar panels, the sun is setting and families are turning on lights, ovens and air conditioners. Explain why a grid that runs mainly on solar and wind needs storage. Describe how storage helps at 6 pm, the energy changes when one storage technology charges and discharges, and which technology suits a calm, cloudy week.

Apply 5 marks