Do Now What are the advantagesdisadvantages to utilizing

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 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 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 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 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!