P3 Flashcards
What happens in a power station?
In coal - or oil-fixed power stations, and in most gas-fixed power stations, the burning fuel heats water in a boiler. This produces steam. The steam drives a turbine that turns an electricity generator. Coal, oil and gas are fossil fuels, which are fuels that come from long-dead animals and plants.
What are biofuels?
A BIOFUEL is any fuel taken from living or recently living organisms. Animal waste is an example of a biofuel. Biofuels can be used instead of fossil fuel in modified engines for transport and in generators at power stations. Biofuels uses waste vegetable oil and plants such as rapeseed. Other examples of biofuels are ethanol from (fermented sugar canes), straw, nutshells and woodchip.
What is a biofuel?
Renewable because its biological source either regrows (vegetation) or is continually produced (sewage and rubbish). This means it is used at the same rate that it is replaced.
Carbon neutral because, in theory, the carbon that the living organism takes in from the atmosphere as carbon dioxide can balance the amount that is released when the biofuel is burnt.
What is nuclear power?
NUCLEAR POWER takes energy from atoms.
The coolant is very hot when it leaves the core. It flows through a pipe to a heat exchanger, then back to the REACTOR CORE.
The energy transferred by the coolant is used to turn water into steam in the heat exchanger. The steam drives turbines that turn electricity generators.
What is wind power?
A wind turbine is an electricity generator at the top of a narrow tower. The force of the wind drives the turbine’s blades around. This turns a generator. The power generated increases as the wind speed increases. Wind turbines are unreliable because when there is little or no wind they do not generate any electricity.
What is wave power?
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.
Wave generators need to withstand storms, and they don’t produce a constant supply of electricity. Also, lots of cables (and buildings) are needed along the coast to connect the wave generators to the electricity to the electricity grid. This can spoil areas of coastlines. Tidal flow patterns might also change, affecting the habitats of marine life and birds.
What is hydroelectric power?
Hydroelectricity can be generated when rainwater that’s 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.
What is tidal power?
A tidal power station traps water from each high tide behind a barrage. The high tide can be released into the sea through turbines. The turbines drive generators in the barrage.
In some coastal areas, electricity is generated by the tidal flow passing through undersea turbines on the sea bend. Underwater cables are used to connect these turbines to the NATIONAL GRID.
Power of the Sun?
Today’s solar cells convert less than 10% of the solar energy they absorb into the energy transferred by electricity. They can be connected together to make solar cells panels.
What is geothermal energy?
Geothermal energy comes from energy released by radioactive substances deep within the Earth.
The energy transferred from these radioactive substances heats the surrounding rock.
So energy is transferred from these radioactive substances heats the surrounding rock.
What are fossil fuel problems?
When coal, oil, or gas is burnt, greenhouse gases such as carbon dioxide are released. The amount of these gases in the atmosphere is increasing, and most scientists believe that this is causing more global warming and climate change. Some electricity comes from oil - fired power stations. People use much more oil to produce fuels for transport.
What are the advantages of Nuclear power?
No greenhouse gases (unlike fossil fuels).
Much more energy is transferred from each kilogram of uranium (or plutonium) fuel than from fossil fuel.
What are the 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. This would affect this area, and the people living there, for many years.
What are the advantages of renewable energy?
They will never run out because they are always be replenished by natural processes.
They do not produce greenhouse gases or acid rain.
They do not create radioactive waste products.
What are the disadvantages of renewable energy?
Wind turbines create a whining noise that can upset people nearby, and some people consider them unsightly.
Tidal barrages affect river estuaries and the habitats of creatures and plants here.
Solar cells need to cover large areas to generate large amounts of power.
