Chapter 2: Energy and the Environment Flashcards
Explain Fossil Fuels and describe the formations of Oil and Natural Gas.
- Fossil fuels are carbon based fuels that are formed over many millions of years from the decay of living matter
- used in direct combustion to create energy sources
- over the years, the remains of organic matter become covered in layers of sediment - subjected to pressure and heat - form fossil fuels
- Oil and gas formation - 300 to 400 million years ago small marine organisms die - remains start layering up - on top =layer of sediment and rock - below=impermeable rock - further below- porous sedimentary rock - bottom= oil and gas begin to form
- today - oil and gas held in a later of porous rock meaning they can be extracted
Describe the step by step formation of coal.
- Huge ofrests cover the expanse of the earth millions of years ago
- vegetation dies and forms peat
- peat is compressed between sediment layers to lignite
- further compression forms coal (anthracitre coal= best quality)
Why is the demand for energy increasing worldwide?
- Increasing population size - more domestic use - higher customer demand - more industrial production
- increasing industrialisation and urbanisation - changing trends and life style - modern industrial societies - change in the demand of people over the last century
- improvements in standards of living and expectations - cosntant need for soemthing new - rapid technological advancements
What is the difference b/w Renewable and Non Renewable Energy Sources?
- Renewable - an item or source that will not be used up or can be replenished - can be used over and over again
- Eg. Geothermal, Wind, Solar, Tidal, Wave, Biofuels, Hydroelectric
- Non Renewable - an item or resource that exists in a finite amount that cannot be replaced
- Eg. Coal, Oil, Natural Gas, Nuclear Power
Explain how electricity is generated using electromagnetic induction
- discovered in 1820s by Michael Faraday - converts kinetic energy into electrical energy usnig loops of a conducting material - coils are rotated near a magnet generating electricity within a generator
1. a heat source in the burner, heats up water that is in the boiler which is converted to steam
2. the steam passes through the blades of the turbine causing them to move
3. as a result of the rotation of the shaft, the copper coils in the generator move, producing electricity that is transferred by condictive wires to the required destination
Energy sources such as fossil fuels, bio fuels, nuclear and geothermal power are used to heat up the water to produce steam
sources such as wind, water, wave, and tidal power can directly turn the turbines
Draw Diagram for clarity
How is electricity produced from a geothermal source?
- Cold water is pumped under pressure into a layer of hot rocks through injection pumps
- the rocks heat the water and production pumps circle it back up to the surface under pressure
- the hot water ehats up a secodn supply of water inside the heat exchanger
- the steam produced in the secodn supply moves the turbine which generates electricity in the generator
- eelctricity travels in power lines
- water is then reused in the same system
draw diagram
How is electricity produced in solar panels?
- uses photovoltaic cells - work on the principle that certain materials when exposed to lgiht produce a small electric charge
- a bank of cells organised into solar panels and a group fo panels arranged into an array can produce significatn electricity
- slighlty expensive as metals in photovoltaic cells are rare
Explain electricity production in wind turbines, tidal plants, and through wave power
Wind Turbines - the rotar blade of the turine moves with the wind - a brake is placed right behind it to stop it during extreme weather conditions so tht it may not sustain damage - a gearbox is placed beidn the brake to maximise the rotation of the shaft as it enters the generator - the generator comes next - produced electricity which then travels down the tower and to the grid connection
Wave Power - uses a turbine and generator - produced by channeling the energy of waves at sea - generation may stop during calm weather conditions when there is little wave production in area
Tidal Power - uses natural rise and fall in the level of water in area during a day - natural tide during night and day - as water levels drop water is held back by a tidal barrage - it releases water back through a turbine - genrrates electricity using generator
draw wind diagram
Economic Factors that affect a country when deciding what energy Sources to use
- Supply of energy is expensive - inelastic demand - will be expensive - especially if imported
- better to use the resources you have - for eg, middle east=oil, russia=natural gas, usa=coal, iceland=geothermal power, long hours of sunlgiht in equator countries
- cost of investing in renewable technology
- availability of fossil fuels
- availability of funds
- priorities of govt
- developing vs developed country
Social Factors that need to be taken into account when deciding the use of Energy Sources
*large scale mining projects for fossil fuels may be expensive and may reduce agricultural land vs may create employment, better infrastructure, provide cheaper raw materials to industry, may increase cheap energy
* could cause displacement (construction of dam for hydro electricity) - vs good developmetn of technology, Multi purpose dams, new manufacturing oppurtunities
* better trade and foreign relations vs bad environmental impact, if imported, low BOP, high inflation
* Mining may cause adverse health affects on people
* risk of nuclear radiation
* the social effects of all energy sources should be taken into account before launching a project - these are examples of some effects in specific scenarios
Environmental questions to answer when deciding how to exploit natural sources for energy.
- many renewables do not have carbon emissions vs fossil fuels are major carbon emitters
*pollution - spillage of fuel in environment - cause damage to wildlife - bruning fuels - toxic gases - changes to ecosystem -destroy habitats - bioaccumulation - biomagnification - ruin fish breeding cycles
- visual pollution - ruin natural beauty
Compare the adv and disadv of using fossil fuels
ADV
* plentiful supply in some locations
* extraction creates employment
* existing technology: to exploit and create fuel from fossils in majority of the countries
DIS
* carbon dioxide and toxic gases emitted - nitrous oxides - carbon monoxide
* extraction causes damage ot local areas
* limited supply - demand pull inflation
* pollution
adv and disadv of using nuclear power
ADV
* does not produce carbon dioxide
* small amount of fuel produces large amounts of energy - half kg uranium rpoduces the same amount as 3 tonnes of coal
* employment
DIS
* risk of radiation leakage
* waste products cannot be recycled as radiation remains active for centuries
* plant has to be evacuated every 30 years
* limited supply
adv and disadv of Biofuels (bioethanol, biogas, wood)
ADV
* renewable source - bioethanol and wood are both obtained from growing plants - biogas from recycling waste products
* growing more plants uses up CO2
* potentially a plentiful supply
DIS
* CO2 and other toxic gases produced when burnt
* a lot of land is used to grow crops for fuel
* potential removal of natural ecosystems to grow crops
adv and disadv of geothermal and hydropower
ADV
* does not produce CO2
* unlimited supply (fir geo - heat from earth used as power source)
* water can be reused
DIS
* can be expensive to install
* only certain areas have suitable conditions
* building of dams impacts natural flow of water (hydro)
* villages and ecosystems may be detroyed when dams and reservoirs are built (hydro)
* may be volatile as it is usually doen on fault lines (geo)
