Do Now
• What are the advantages/disadvantages
to utilizing the following compared to
fossil fuels:
• Solar Power
• Wind Power
• Geothermal Power
• Hydroelectric Power
CHAPTER 24 SUN, WIND AND WATER ENERGY
FUELED
BY THE SUN
A tiny island makes big strides with renewable energy
A Danish community transforms from using
imported fossil fuels to being independent
with renewable energy sources.
Renewable Energy
Energy from sources that are replenished
or are perpetually available
Sustainable Energy
Renewable energy with low
environmental impact
How Most Renewable Energy
Technologies Work
1. Some force moves a turbine (turbine is like a
propeller)
a) Wind – moving air
b) Nuclear – steam produced by nuclear reaction
c) Hydropower – moving water
2. Turbine turns the generator.
3. Generator produces electricity
4. Electricity transmitted via the grid to homes.
Wind Energy
Energy derived from the motion of
air across Earth’s surface
Converting Wind to Electricity
Do Now
• What is solar energy, and how does it
work?
• What types of solar energy exist?
• How effective are solar panels at
converting the suns energy into
electricity?
Solar Energy
Energy harnessed from the sun in the form
of heat or light
Solar Technologies
1. Photovoltaic (solar) Cells: convert solar energy
directly into electricity.
2. Active Solar: use of mechanical equipment to
capture and convert solar energy to usable form.
3. Passive Solar Technology: capture of solar
energy without electronic or mechanical aids.
4. Solar Thermal System: active capture of solar
energy for heating.
Passive Solar Technology
Solar Hot Water Heaters
Photovoltaic Cells
Samsø’s Windmills
Geothermal Energy
Energy harnessed from the heat of
underground fluids
Geothermal Power Plants
Use hydrothermal heat to produce steam
to turn turbines that drives the generator
to provide energy for the grid
Almost all homes in Iceland are heated
by geothermal energy
Hydropower
Energy harnessed from moving water
Provides more electricity around the world
than any other renewable source
A serious problem with hydropower is
the habitat destruction that occurs from
flooding to create the dam and reservoir
Issues with Renewable Energy Sources
1. Currently expensive – but price will go down as
technologies improve
2. Payback time – time to save enough money to pay for
the equipment
3. Intermittency – sun does not shine at night;
- wind does not blow all day
4. Cannot store energy – large batteries do not exit
Conservation
Making choices that use less energy
20% of the average home electricity bill
is from lighting. How can you save money?
Simply turn off lights or switch to more
efficient bulbs (e.g., compact fluorescent).
Energy-Saving Strategies
Within a few years Samsø was producing
more energy from renewable sources
than it was using!