2 What is fuel? A fuel is a substance that provides a form of energy Energy can be in the form of heat, light, electricity, or motion.When fuel is burned it releases energy: this is called combustion.
3 Fossil fuels What is a fossil? What is a fuel? Fossil fuels are the energy-rich substances formed from the remains of once living organisms.Three fossil fuelsCoalOil (petroleum)Natural Gas
4 Nonrenewable resources Fossil fuels are non-renewable – they are being used up faster than they are made.Fossil fuels often cause political problems in the world because they are unevenly distributedQuick!What are the three fossil fuels?CoalOilNatural Gas
5 Alternative Energy Resources We need to find alternative energy resources so that we do not use up all of our nonrenewable resources
6 Renewable Resources A renewable resource is constantly being supplied. What are some renewable resources?
7 Solar Energy Solar energy – light and heat energy from the sun Solar energy is the source of most other renewable energy resourcesHow?Wind – unequal heating of the Earth causes global windsWater – sun heats water for evaporation to start the water cycle
8 WindWindmills generate large amounts of electric power
9 Flowing WaterHydroelectric power is electricity produced by flowing waterWater flows throughtunnels and turnsturbines connectedto a generator.Most widely usedalternative energysourceTidal energy - Thetide moves a hugeamount of watertwice each day
10 Biomass fuelsBiomass fuels are fuels made from things that were once aliveWoodLeavesFood wastesManure
11 Geothermal Energy Magma heats up water underground The hot water and steam are valuable sources of geothermal energy
12 Sometimes we can have a resource that is non-renewable, but is still an alternative energy resource. That means it causes less pollution, but once we use it all it is gone!
13 Nuclear EnergyIn a nuclear power plant, heat is released from reactions, and turns water to steamThe steam turns a turbine to generate electricity