RENEWABLE ENERGY
Solar Energy
 Power from the sun
 Produced by nuclear fusion reactions in the sun’s
core
 Passive Solar Heating:
 Uses the sun’s energy to heat something directly
 Oriented according to the yearly movement of the sun
 Active Solar Heating:
 Energy from the sun is gathered by collectors & used
to heat water or to heat a building
 Photovoltaic Cells:
 Convert the sun’s energy into electricity
 Energy is stored in batteries which supply electricity
when the sun is not shining
Passive Solar Heating
Active Solar Heating
Wind Power
 Converts the movement of wind into
electrical energy
 Fastest growing energy source in the world
 Cost has declined
 Problem with transporting electricity
Biomass
 Using plant material, manure &
any other organic matter as an
energy source
 Methane
 Produced when bacteria decompose
organic wastes
 Can be burned to generate heat or
electricity
 Alcohol
 Produced by fermenting fruit or
agricultural waste (ex: ethanol from
corn)
Hydroelectricity
 Produced from the flow of moving water
 20% of the world’s electricity
 Water in a reservoir is released to turn a turbine,
which generates electricity
 Expensive to build, relatively inexpensive to
operate
 Doesn’t contribute to acid rain like burning fossil
fuels does
 Dams last longer than most fossil fuel power
plants do
 Changes a river’s flow & can disrupt ecosystems
Geothermal
 The energy from heat in the Earth’s crust
 Power plants pump heated water or steam
from rock formations and use the water or
steam to power a turbine that generates
electricity
 Water must be managed carefully so it is not
depleted
 Geothermal heat pumps can be used to both
heat & cool homes
Geothermal
Conservation Around the Home