Fossil fuels are used to produce twokinds of energy that are veryimportant to us.Let’s first look at mechanicalenergy—the energy of movingthings. You and others depend onmany things that move.What are some of these things?
But in order to move, allthese vehicles must have afuel.What fuels do these vehiclesburn?
The fuel foreach of thesevehicles usuallycomes fromcrude oil, afossil fuel.
Rememberall the fuelsthat comefrom crudeoil?Gasoline, dieselfuel and jet fuelare the fuels fortransporation.
Another form of energy wedepend upon is electricity.But electricity has to be generated.Just how is electricity generated?
To generate electricity youhave to turn a magnetinside a coil of wire or turna coil of wire inside amagnetic field.
Open this website to seehow this is done.http://new.wvic.com/index.php?option=com_content&task=view&id=9&Itemid=46
And what force is used toturn the wire or magnet?Often it is steam.Coal and natural gas(two more fossilfuels) are burnedheating water tomake steam.
The burning coal The waterCoal is changes intoburned. heats the water. steam.The steam turns The turbine turns Electricity isthe turbine. the coil of wire generated. inside the magnet.
The electricity travels from the powerplant by wires to your house.
But there are many problems withburning the three fossil fuels.1. coal2. natural gas3. crude oil --gasoline anddiesel fuelWhat are some of these problems?
• They are limited and very expensive. -Crude oil is becoming hard to find and even more expensive to obtain. • Burning these fuels puts: -pollutants into the air which are harmful to our health and -carbon dioxide into the air which leads to global warming.• Accidental spills, as in the recent Gulf Oil spill, pollute our water.
So what are we to do?Man can use other (alternative)forms of energy to move ourvehicles and generate electricity.What are some of thesealternative forms of energy?
These arealternativeforms ofenergyFirst let’slook atbiomass.
Biomass is organic material madefrom plants. Biomass containsstored energy from the sun.Some examples of biomass fuelsare wood, corn, sugar cane andsome types of garbage.But where do these plant materialsget their energy?
During photosynthesis, pl ants change the sun’s radiant energy into chemical energy in the form of a sugar called glucose.So the energy from the sun is actually stored inthe structure of the plant.
When plant material is burned, thestored chemical energy is released asheat. If you have a fireplace, the woodyou burn in it is a biomass fuel.Wood waste and certain garbage(forms of biomass) can be burned toproduce steam for making electricityand also to provide heat for homesand industries.
Sugar cane and corn can be used toproduce ethanol, a liquid fuel, that can beadded to gasoline for vehicles.Biodiesel, another transportation fuel, canbe produced from left-over food productslike vegetable oils and animal fats.
Alternativeforms ofenergyThen there ishydropower.
Dams are used to channel ariver’s water flow throughhydropowergeneratorsproducingelectricity.
The flow of water powers the turbine thatturns the magnet (or the coil of wire)inside the generator producing electricity.
Geothermal energy is createdby heat from inside the Earth.
Water isinjectedunderground.Heated by the rock, it turns intosteam which can be used to heatbuildings or to generate electricity.
Alternativeforms ofenergyThen there isthe wind.
Remember wind is caused byunequal heating of air.
Wind is usedto turn theturbine insidean electricalgenerator.
Alternativeforms ofenergyAnotheristhe energyof the Sun.
Solar energy can be convertedto electricity in two ways:
First, solar cells change the energyfrom the Sun (solar energy) directlyinto electrical energy.
It would take many many solar cells toprovide for all of a city’s electrical needs.
The second way the Sun can be used to fluid produce electricity is by using: mirrorsConcentrating Solar Power Plants togenerateelectricity. Mirrors reflect and focus the sun’slight on acontainerof fluid. Thehot fluid changeswater intosteam which isused to powera generator.
Can you think ofIn summary some advantages ofThese these alternativeare some forms ofof the energy?alternativeDo they haveanyforms ofdisadvantages?energy
Below is a website that has good readingmaterial that you can print (in black andwhite) alternative energy sources such aswind, solar, biomass and geothermal.Under the tab student choose EnergyInfobooks. Both the Complete Primary andElementary Energy Infobooks are excellent.So are the individual printouts on eachenergy source such ascoal, petroleum, naturalgas, wind, solar, etc. (http://www.need.org/)
A particular slide catching your eye?
Clipping is a handy way to collect important slides you want to go back to later.