4.2 Energy From Wind and Water

Question 1

What makes a renewable source of energy?

Answer 1

The sources can never be used up

Question 2

How do we get energy from wind?

Answer 2

In a wind turbine, the wind blowing over the blades makes them rotate, driving a generator at the top of a narrow tower

Question 3

How do we get energy from a hydroelectric power station?

Answer 3

At a hydroelectric power station, water is collected in a reservoir and is allowed to flow downhill, passing a turbine. The falling water drives the turbine

Question 4

What is a pumped storage system?

Answer 4

A hydroelectric power station that is reversible

Question 5

How does the pumped storage system part of the hydroelectric power station work?

Answer 5

In times of low demand for electricity, the extra energy is used to pump the water back up the hill to the reservoir, meaning the energy is stored

Question 6

What do hydroelectric power stations do in high demand?

Answer 6

They turn on very quickly and let the water flow so the stored energy can become electrical energy

Question 7

What form of energy is stored in the water in the top of the reservoir of a pumped storage scheme?

Answer 7

Gravitational potential energy

Question 8

How does wave energy become electrical energy?

Answer 8

The movement of the waves drives a floating turbine that turns a generator, the electricity is then delivered to the grid system on shore by a cable

Question 9

How can we get electrical energy from tidal power?

Answer 9

A barrage is built across a river estuary so the water can be trapped behind it at each high tide. When the water is released it falls down to sea level and drives the turbines

Question 10

Why is wave power likely to be less reliable than tidal power?

Answer 10

There are always two tides per day, whereas there’s no guarantee that there will be waves each day

Question 11

Name 3 types of renewable energy

Answer 11

• wind
• water
• waves