P3 Energy Resources Flashcards
How is electricity generated in a coal, oil, or (most) gas fired power stations?
Burning fuel heats water in the boiler. This produces steam. The steam drives a turbine that turns an electricity generator
Examples of fossil fuels
Coil, oil and gas
What is a biofuel?
Any fuel taken from living or recently living organisms
What is biodiesel made of?
Waste vegetable oil and plants such as rapeseed
Examples of biofuels
Biodiesel, ethanol (fermented sugar cane), straw, nutshells, and woodchip
What fuel is used in nuclear power stations?
Uranium (or plutonium)
How does a nuclear power station generate electricity?
Energy is transferred from the nucleus when the uranium atom is split into two. The core becomes very hot due to the large number of uranium atoms. The coolant is pumped through the core and the energy transferred is used to turn water into steam in the heat exchanger.
How do wind turbines generate elctricity?
The force of the wind drives the turbine’s blades around. This turns a generator.
Negatives of wind power
They are unreliable as when there is little or no wind they do not generate electricity
How does wave power generate electricity?
A wave generator uses the waves to make a floating generator move up and down. This motion turns the generator so it generates electricity. A cable between the generator and the shoreline delivers electricity to the grid system
Negatives of wave power
They need to withstand storms and they don’t produce a constant supply of energy. Also, lots of infrastructure is needed along the coast to connect the wave generators. This can spoil the coastline. Tidal flow patterns may also change
How does hydroelectric power generate electricity?
Rainwater that is collected in a reservoir (or water in a pumped storage scheme) flows downhill. The flowing water drives turbines that turn electricity generators at the bottom of the hill
How does tidal power generate electricity?
A tidal power station traps water from each high tide behind a barrage. The high tide can then be released into the sea through turbines. The turbines drive generators in the barrage.
What is Geothermal energy?
Geothermal energy comes from energy released by radioactive substances deep within the Earth
How does geothermal energy generate electricity?
Geothermal power stations can be built in volcanic areas or where there are hot rocks deep below the surface. Water gets pumped down to these rocks to produce steam. Then the steam that is produced drives electricity turbines at ground level
What are solar cells?
Flat solid cells that use the sun’s energy to heat water directly
What are solar heating panels?
They use the sun’s energy to heat water directly
How does a solar power tower generate electricity?
It uses thousands of flat mirrors to reflect sunlight on to a big water tank at the top of a tower. The mirrors on the ground surround the base. The water in the tank is turnedto steam by the heating effect of the solar radiation directed at the tank. The steam is piped down to ground level, where it turns electricity generators.
Rank oil, coal and gas in order of increasing greenhouse gas emissions
Gas, Oil, Coal (most greenhouse gas)
Burning fossil fuels can produce sulfur dioxide which causes…
Acid rain
Advantages of nuclear power
No greenhouse gases
Much more energy is transferred from each kg of uranium fuel than from fossil fuel
Disadvantages of nuclear power
Used fuel rods contain radioactive waste, which has to be stored safely for centuries
Nuclear reactors are safe in normal operation however an explosion in a reactor could release radioactive material over a wide area
Advantages of renewable energy sources
They will never run out
They don’t produce greenhouse gases or acid rain
They don’t create radioactive waste products
They can be used where connection to the national grid is uneconomical
Disadvantages of renewable energy
- They aren’t currently able to meet world demand
- Wind turbines create a whining noise and ruin views
- Tidal barrages affect river estuaries and the habitats
- Hydroelectric schemes need large reservoirs of water which can affect nearby animal and plant life. Habitats are often flooded to create dams
- Solar cells need to cover large areas to generate large amounts of power
