Generating Energy

Generating Energy

1. Nuclear Energy

   • Nuclear fission produces energy
     • Atoms split
       • Lots of heat energy
     • Water sprayed as coolant
       • Reduce heat
   • Fission
     • Heat produces steam
       • Spins a turbine
         • Dive a generator
           • Converts kinetic energy of movement into electrical energy
   • Advantages
     • Lots of energy
       • More than burning
         • 10000 x more than 1g oil
     • No CO2 produced
     • Relatively cheap
       • Uranium
   • Disadvantages
     • Radioactive waste
       • Difficult to dispose
       • Radioactive for long time
       • Ionising radiation
     • Irradiation
       • Exposed but no contact with source
       • Not as bad as contamination
       • Only short period of time
         • Less exposure = less damage
       • Measures put in place to reduce
         • E.g. badges
     • Contamination
       • Picking up radiation
         • Breathe in
         • Swallow
       • Stays in once left area
       • Long exposure = more damage
     • Extra safety precautions
       • Careful disposal
       • Check workers regularly
       • Surrounding area tested for contamination
     • Lack of support
       • People nearby scared of risks
     • High start up cost
       • And decomissioning

2. Wind Turbines

   • Lots of turbines in windy areas
     • Coast
     • Moors
     • Exposed areas
   • Each has generator inside
     • Wind turns turbine
       • Drives generator
         • Produces electricity
   • Advantages
     • No CO2 pollution
       • Only when built/ transported/ put up
     • Renewable energy source
     • No fuel costs
     • Minimal running costs
     • No permanent damage to landscape if removed
   • Disadvantages
     • Very noisy
     • No power when wind stops
       • Impossible to increase supply with high demand
     • High initial costs
     • Spoil view
       • Lots needed
     • Lots needed for same energy as coal burning
       • 1500

3. Solar Cells

   • Relatively small scale e.g. powering individual houses
   • Mainly used when not much energy needed
     • Calculators
     • Watches
   • Remote places where there isn't much choice
     • Australian Outback
       • Power road signs and satellites
   • Advantages
     • No pollution once manufactured
       • Renewable
     • Very reliable in sunny countries
       • Cost effective in cloudy countries
     • Free energy and virtually no running cost once installed
   • Disadvantages
     • Lots of energy to manufacture
     • Not practical/ too expensive to connect to National Grid
     • Initial costs are very high
     • No energy at night
     • Can't increase supply to meet high demand

4. Wave Power

   • Lots of small wave-powered turbines around coast
   • 'Up/down' wave motion spins turbine
     • Drives generator
       • Produces electricity
   • Advantages
     • No pollution
     • Renewable
     • No fuel costs
     • Minimal running costs
   • Disadvantages
     • Initial set up costs high
     • Hazard to boats
     • Unreliable
       • Drop in wind = drop in energy
       • Can't increase supply to meet high demand
     • Spoil view
   • Not good large scale, but useful on small islands

5. Tidal Barrages

   • Dams built across river estuaries with turbines in
   • Tide in fills estuary to several meters high
     • Drives turbines
       • Water let through at constant speed
       • Drive egenrators
     • Higher = more water = more energy
   • Source is gravity of the Sunand Moon
     • Controls tides
   • Advantages
     • Potential to generate significant amount of energy
     • No pollution
     • Can store energy ready for peak demand
     • Renewable
     • Reliable
       • Always twice a day
     • No fuel costs and minimal running costs
   • Disadvantages
     • High set up costs
     • Prevent free access by boats
     • Spoil view
     • Alter habitat of wildlife
     • Height of tide is variable
       • Lower = less energy
     • Don't work when water level is the same either side of the dam
       • 4 x per day due tot tides

6. Biofuels

   • Made of plants and waste
   • Many forms
     • Solid
       • Straw/ woodchips
     • Liquid
       • Ethanol
     • Gas
       • Methane biogas
   • Advantages
     • Carbon neutral
     • Renewable
     • Quick
     • Can be used in stars
   • Disadvantages
     • Takes up room that could be used for crop
     • Forest has been cleared to make room
       • Ruined habitat
       • Increased CO2 and methane emissions
         • From cutting down trees
         • Less removed
   • Plants burned to produce steam to spin turbines and generators

7. Geothermal Energy

   • Only where hot rocks lie near surface
   • Cold water pumped down to hot rocks in pipes
     • Returns as steam
       • Spins a turbine and generator
   • Advantages
     • Renewable
     • Free
     • No real environmental problems
   • Disadvantages
     • Costly to drill several km to hot rocks
     • Very few places this is an economic option

8. Hydroelectricity

   • Flood valley to make resevior by building large dm
     • Rain water is caught int eh resevior
       • Gravity causes water to rush through turbines
         • Generator converts kinetic energy into electricity
   • Advantages
     • No gaseous pollution
     • Renewable
     • Immediate response to increased demand
     • No fuel costs
     • Minimal running costs
     • Reliable
   • Disadvantages
     • Rotting vegetation releases methane and CO2
     • Animal habitats destroyed
       • From flooding for resevoir
     • Ruin view when dried up
     • High initial costs
   • In remote areas to reduce human impact