Unit 1: 4 - Generating Electricity Flashcards
What does steam drive in a power station?
Turbines.
What are the turbines linked to, to generate electricity?
A generator.
What are fossil fuels and where do they come from?
Coal, oil or natural gas comes from long-dead biological material.
What is the benefit of a gas fired turbine?
It can be switched on very quickly.
What is a biofuel?
A fuel obtained from living or recently living organisms (They are renewable).
What process generates energy in a nuclear power station?
Nuclear fission.
What fuels are usually used in a nuclear power station?
Uranium or plutonium.
Which fuel currently releases the most energy per kilogram of fuel?
Uranium.
What type of energy comes from wind, waves or tides?
Renewable.
How do wind and water turbines work?
Wind/water drives the turbines directly, which are attached to a generator.
What water sources do we use for generating electricity?
Falling water, waves or tides.
How does a HEP station work?
Water is stored in a reservoir. The water is then allowed to flow downhill and turn turbines at the bottom, and generate electricity.
What is a pumped storage system?
Surplus (leftover) energy is used at times of low demand to pump water back up the hill to the reservoir. Then the energy is stored as gravitational potential energy, which can be released when needed to generate electrical energy.
How does wave power provide electrical energy?
A floating turbine is placed offshore. Waves then turn the turbine, and the electrical energy is sent onshore by a cable.
How does tidal power provide electrical energy?
The sea level rises and falls twice a day. A barrage is built in an estuary so water is trapped when it falls again. When the water is released, it drives turbines.
Why is wave power less reliable than tidal power?
Because tidal power is consistent, and can be very easily predicted. Wave power depends upon the weather amongst other factors.
How does solar energy from the Sun travel to the Earth?
As electromagnetic radiation.
Why are solar cells not particularly useful?
They are very inefficient.
What is a solar power tower?
A device that uses thousands of mirrors to reflect sunlight onto a water tank and produce steam.
What is the National Grid?
A network of pylons and cables that connects power stations to homes, schools, factories and other buildings.
What is the voltage of the National Grid?
132,000V or more.
What voltage do power stations output electricity at?
25,000V.
How is voltage increased?
By using step-up transformers.
How is voltage decreased for use in the home?
By using step-down transformers.
