P2 ocr gateway

P2 ocr gateway

1. using the suns energy

   • capturing the suns energy with photocells
     • photocells (solar cells) generate electricity directly from sunlight
     • they generate DC (direct current)
     • made of silicon, the atoms absorb some of the energy, knocking loos some electrons, these then flow round a circuit
     • the current and power output of a photocell depends on: surface area, intensity of light, the distance from light source

2. solar and wind power

   • passive solar heating
   • wind farms
   • wind is a renewable source
     • wind turbines are cheap to run, no polluting waste, renewable
     • 1500 turbines replace 1 coal fired power station, visual pllution (ruin view), wind can not be fast enough, blades make noise (noise pollution), impossible to increase suply when demand, expensive to set up, hard to find somewhere

3. power stations

   • fuel, boiler, steam, turbine, generator, national grid
   • fossil fuels
   • biomass
   • nuclear power
   • photcells
   • wind power

4. electromagnetic

   • the creating of a voltage and maybe current in a wire which is experiencing a change in magnetic field

5. greenhouse effect

   • carbon dioxide
     • cars, fossil fuels, chopping/burning trees
   • Methane
     • cattle, volcanoes, wetlands
   • water vapour

6. alpha, beta, gamma

   • alpha particles are big and heavy and are stopped by a sheet of paper
   • beta particles are electrons, stopped by aluminium
   • gamma rays are very high frequency electromagnetic waves, thick lead stops gamma