Generating electricity Flashcards
how do fossil fuels work?
they are burnt to heat water and make steam. this steam turns a turbine which then turns a generator making electricity
advantages of fossil fuels
- very large amounts of electricity can be generated in one places using coal, fairly cheaply
- can be built almost anywhere
disadvantages of fossil fuels
-produces carbon dioxide, which contributes to the “greenhouse effect”
-coal produces sulphur dioxide, a gas that adds acid to rain
how does Nuclear power work?
Nuclear fission gives out a massive amount of heat energy. this then heats water to make steam, this steam turns a turbine generating electricity.
advantages of nuclear power
-does not produces smoke or carbon dioxide, so it doesn’t contribute to TGHE
- ITS RELIABLE
Disadvantages of nuclear power
-Nuclear waste is difficult and expensive to remove
- Nuclear power plants are a target for terrorist attacks
how does wind power work?
The wind makes the blades of the turbine spin, this turns a generator inside the head of a wind turbine which makes electricity
advantages of wind power
- wind is free, wind farms need no fuel
-produces no waste or greenhouse gases
-the land beneath can usually still be used for farming
disadvantages of wind power
- the wind is not always predictable
-some people feel covering the landscape with these towers is unsightly
How does geothermal power work?
water is pumped through the ground where there are hot rocks. this water turns into steam, the steam turns a turbine, turning a generating creating electricity
advantages of geothermal power
-it does not produce any pollution, and does not contribute to TGHE
-No fuel is needed
disadvantages of geothermal power
-there are not many places where you can build a geothermal power station
- Hazardous gases and minerals may come up from underground
how does tidal power work?
The tides make sea and ocean water move.
as this water moves it can turn blades on a turbine, as the blades spin they turn a generator inside which makes electricity
advantages of tidal power
- once you’ve built it, tidal power is free
-it produces no greenhouse gases or other waste
disadvantages of tidal power
- the environment is changes for many miles upstream and downstream
-only provides power for around 10 hours each day, when the tide is actually moving in or out
how does hydroelectric power work?
water in a lake high up can be released through a pipe and as it falls it makes blades of a turbine spin, which then turns a generator making electricity
advantages of hydroelectric power
- water can be stored above the dam ready to cope with peaks in demand
- much more reliable than wind, solar or wave power
disadvantages of hydroelectric
- the dams are very expensive to build
- building a large dam will flood very large areas
- finding a suitable site can be difficult
renewable energy sources
can be used again and again and will never run out or are easily replaced
non renewable energy sources
cannot be used again and will run out in the future , they are not easy to replace
the national grid
is a network of power stations, transformers, pylons and cables that reliably distribute electricity to our homes and factories on demand
step up transformers
increase voltage so the current is lower and the wires don’t waste heat energy meaning it is more efficient
step down transformers
decrease the voltage to a safe level for us to use.
voltage at homes
230V
voltage at power stations
25,000V
voltage at pylons and cables
400,000V
How do you calculate energy efficiency
useful energy out/ total energy supplied X 100
reliable energy sources
-nuclear power
-hydroelectric
efficient energy sources
-wind energy
-solar power
-geothermal energy