Questions What is needed to produce electricity from wind energy on a large scale? SA: Ch: 5 Sec: 3 Part 2 “Alternative Resources” EQ: How do humans use Solar Energy? May 19, 2015 Agenda 1.Roll 2.Chapter 5 Section 3 Part 2 “Alternative Resources” 1.Video: “Electricity and Magnetism” Come in Quietly and sit at your desk, open to your notes, write the new question, and wait quietly for class to begin.

Sitting in the Sun When sunlight falls on your skin, the warmth you feel is part of solar energy.

Solar Energy Solar energy is energy from the sun.

Every day, the Earth receives more than enough solar energy to meet all of our energy needs. Solar Energy

Solar energy is considered to be a renewable resource. Solar Energy

Solar energy can be changed directly into electricity. Solar Energy

Solar Calculator Solar calculators receive all the energy they need from their solar cells.

Solar Cell A single solar cell produces a small amount of energy.

Solar Cells This is good for small devices yet, many are needed to supply energy for larger devices and homes.

Solar Cells Solar cells are quiet, reliable and have no moving parts, can last for years with little maintenance, and produce no pollution.

Solar Panels Solar panels are very expensive. In the long run they do pay for themselves.

Have you seen solar panels? What other ways have solar panels been used?

Solar Heaters Solar energy can be used for direct heating through solar collectors.

Solar Collectors Solar collectors are dark-colored boxes with glass or plastic tops. The sun makes the boxes very hot. Water can run through these boxes and be heated.

Solar Collectors Solar collectors are very expensive, yet in the long run they will eventually pay for themselves. They can also be used to generate electricity.

Large Scale Solar Power Large scale solar power uses mirrors to focus the sunlight and heat pipes filled with synthetic oil.

Large Scale Solar Power This oil will be circulated to heat water that will cause steam. The steam will then be used to drive an electric generator.

Large Scale Solar Power Another design uses mirrors to focus the sunlight on a central tower.

Large Scale Solar Power The energy is then stored in salt. The salt is then used to create steam that will drive an electric generator.

Capture the Wind Wind is created indirectly by solar energy through the uneven heating of the air.

Wind Energy There is a tremendous amount of energy in the wind, called wind energy. You can see the effects of this energy in hurricanes and tornados.

Wind Energy Wind energy can be used positively by humans.

Windmills Windmills have been used to pump water from the ground and generate electricity since the 1920’s.

Wind Turbines The modern windmill is called a wind turbine. Clusters of these wind turbines are often called wind farms.

Benefits to Using Wind Turbines Wind turbines take up only a small portion of ground surface. This allows the land to be used for more than one purpose.

Wind energy is renewable. Wind farms can be built in 3 – 6 months. Wind turbines produce no air pollution. Benefits to Using Wind Energy

Disadvantages to Using Wind Energy Wind only blows strongly and steady only in some places in order to produce electricity on a large scale.

“Electricity and Magnetism” 1.What did you know? _____________________________________________ 2. What did you learn? _____________________________________________ 3. What do you want to know? _____________________________________________

Review 1.What are two ways of using solar energy? Response: Two ways of using solar energy is … 2.What is needed to produce electricity from wind energy on a large scale? Response: In order to produce electricity from wind energy you need … 3.What are solar collectors used for? Response: Solar collectors are used for …