November test Weeks 6-10 Flashcards
how is electricity produced (generally)
- involves rotating a turbine which turns a generator
- fossil fuels burned to create heat to superheat the water
- steam turns turbine (linked to generator) to produce electricity
Fossil fuels advantages
- cheap and reliable (does not rely on weather)
- well developed systems to harness energy
Fossil fuels disadvantages
- contains high levels of carbon and contributes to global warming
- non-renewable and unsustainable
- accidents could occur to add to pollution and environmental contamination
What are fossil fuels
- finite resources
- gas -> electricity in the UK, heating and cooking
- coal -> burned to create energy
- oil -> create plastics or fuel
- burning these fuels produces large amounts of CO2 (climate change)
What is shale gas?
- a natural gas trapped in the earth’s crust
- fracking: process to release gas from shale
- sends a high pressure mixture of water, sand, chemicals into the rock to release gas
Why is fracking controversial?
- fractures rock to release gas -> causes earth tremors that damage building foundations
What is nuclear power?
- produces energy by fission (splitting uranium atoms in a nuclear reactor)
- same heat/steam/turbine process as coal power station except heat is made with nuclear fission
Advantages of nuclear power
- no need for a large amount of space to generate electricity
- does not produce CO2 or contribute to global warming
- reliable (not dependant on weather)
- low volume of waste produced
- reduces demand for finite resources
Disadvantages of nuclear power
- risk of nuclear accidents
- disposal of nuclear waste (expensive), takes a long time to decay
- high levels of security of needed (terrorism)
- decommissioning nuclear plants safely-> costly (high risk of contamination)
- construction, operation and decommissioning nuclear power plant may harm the environment
what is renewable energy?
Natural sources of energy that are non-finite and can be quickly replenished (eg. wind, biomass, solar)
What is wind power?
energy from wind turns propeller-like blades on rotor (connected to generator)
Advantages of wind power
- cost effective
- clean source of energy
- sustianable and renewable
Disadvantages of wind power
- unpredictable (weather based)
- can be noisy
- affect visual appearance of landscape
- distance from wind sites (location on hilltops or out at sea) = high costs to connect to national grid
what is tidal power?
- movement of water (tide) turn underwater turbines which drive the generators
Advantages of tidal power
- predictable
- renewable
- clean source of energy
Disadvantages of tidal power
- expensive to set up and maintain
How do solar panels create energy
- abosorb light into photovoltaic cells which is converted into electricity
Advantages of solar panels
- renewable
- clean
- energy can be collected on sunny or cloudy days
Disadvantages of solar panels
- low energy generated during winter months (daylight hours are shorter)
What is biomass and how is it used?
- produced from organic matter
- energy extracted by burning/ anaerobic digestion (no air, bacteria breaks down organic matter and produces methane)
- methane can be used to heat homes or fuel
Advantages of biomass
- renewable
- carbon neutral
Disadvantages of biomass
- risk of deforestation if trees are not planted
- CO2 emissions are made (global warming)
What is hydroelectric power?
- turbine converts kinetic energy of falling water into mechanical energy and generator turns it into electricity
- eg. dams
Advantages of hydroelectric power
- renewable
- reliable
- clean
- regulated according to demand (can be switched on and off)