Renewable Energy P32,34 Flashcards
What are renewable energy sources
Energy that comes from the planets non finite resources
What do renewable sources include
Wind Wave and tidal Hydroelectric Geothermal Biomass Solar energy And sometimes nuclear energy
Why are some people against including nuclear energy in a list of renewable energy
The harmful nuclear waste produced by nuclear power reactors
Waste is considered radioactive pollutant
Turbines and generators
How they work
Most forms electricity production invoke rotating turbine which turns a generator
Fossil fuels burnt to create heat
Heat superheats water
The steam from heated water is used to rotate turbines which are linked to a generator
Generator provides a supply of electricity
Fossil fuels
Generating electricity
Resource type
Affect to environment
Most of the heat used to generate electricity in UK from burning fossil fuels ie coal, gas, oil
Considered finite resources as cannot be replaced as they run out
When fossil fuels burnt produce co2
Some modern power stations can scrub exhaust gas emissions by trapping co2 but still generally not environmentally friendly or sustainable
Shale gas
What is it
A natural gas that is trapped within areas of shale in the earths crust.
It is a sedimentary rock that can be rich source of petroleum and natural gas
Fracking
What is it
Environmental impact
Controversial process of extracting gas from the shale rock
Involves drilling a well down into the earths crust and then sending a high pressure water, sand and chemical mixture into the rock to release trapped gas
Gas travels back up the drilled shaft and is collected at the well head
Environmentalists believe it can damage the environment by releasing gases and other toxic particles into the water also consents it can cause earth tremors
Wind turbines
Pros and cons
Cheap option
Wind turbines produce more power in the winter months when the demand is higher but have some drawbacks
Do not produce power when no wind
Harm wildlife ie birds
Eyesore
NIMBY - not in my backyard! (Stopped many being developed)
Solar energy
What is it
Photovoltaic effect involving the conversion of solar energy into electrical energy
Price of producing photovoltaic cells have dropped recently meaning it has only just become a viable method for large scale production
Only produce energy in daytime and less in winter months when less sun
Tidal energy
Few different tidal energy devices but all use same principle to generate electricity
Rely on movement of water to turn turbines which drive the generators to produce electricity
Benefit: more predictable and consistent
Difficulty: environment where the machinery is located - harsh, distance from land, repair etc more hard
Hydroelectric power
(HEP)
Reliable source of renewable energy
High initial set up costs - financially and environmentally
Vast areas of land need to be flooded to create reservoir - usually mature into thriving leisure facilities ie boating lakes and nature reserves so can have positive impact on local area
Energy production more efficient during periods of heavy rainfall
Other times water is pumped back up to top of reservoir when demand electricity low
Flow of water through turbine easily controlled making it simple to alter power being produced depending on demand
Biofuel
Becoming viable way of producing energy for our transportation and heating needs
Oil and starch producing crops are grown, harvested and refined into a number of products including biodesiel
Process commonly known as biomass energy production
Can include solid biofuels such as wood chips and farm waste
Products produced from biomass considered carbon neutral as they absorb co2 whilst growing and produce similar levels co2 when burned for energy
Do require additional energy to convert to usable fuels
Nuclear power
Considered clean and efficient energy source and provides over 11% of the worlds electricity
Process harnesses a nuclear reaction that takes place inside the reactor vessel
Control rods are moved in or out of reactors core to regulate the amount of power that is generated
Reaction generates vast amounts of heat which like other methods superheats water and generates power by driving turbines and generators
Downside is expensive to build a reactor and waste product is radioactive and very dangerous to all forms of life
Must be contained correctly and carefully stored so that the radiation does not leak
Nuclear waste is usually stored underground as it stays radioactive for a long time - some for millions of years
