Earth and Space Energy Resources: Wind, Sun, and Moon

Wind Energy Convert energy from wind to mechanical energy- windmills Convert energy from wind to electrical energy- wind turbines A 1-megawatt wind turbine provides enough energy to supply households.

Wind Energy Advantages Renewable resource Do not produce greenhouse gases while in use Disadvantages Interfere with the natural beauty of the landscape Can not predict winds in terms of time and speed

Effect of Sun and Moon on Earth Sun is most important in terms of energy emission of light and heat Moon exerts gravitational force causing tides

Energy Emission of Sun The Sun is a star that is composed of 75% Hydrogen and 25% Helium Energy is transported by rays Infrared Visible Light Ultraviolet 8 minutes for the rays to travel from the Sun to the Earth (150 million Km)

SUN The rays heat the atmosphere, oceans and the ground Tropical regions receive more solar energy than the poles WHY? The Earths curve

SUN These different temperatures create the winds and the oceanic circulation This leads to natural phenomena

Solar Energy Solar energy: the energy that is given from the sun by the rays that travel to earth In 1 hour the earth receives enough solar energy in the form of heat and light to supply us with enough energy for our needs for a year but capturing this energy is difficult

Solar Energy Technology 3 Types 1. Passive Heating 2. Photovoltaic Cells 3. Thermal Collectors

Solar Energy Technology Passive Heating: This system consists of orientating the house to get the maximum light from the sun. The rays pass through windows and heat the air inside. Material inside like concrete trap heat and can give it off when the sun goes down

Solar Energy Technology Photovoltaic Cells : serves as feeding devices with electricity The material in the cells is usually Silicon. The light hits the cell and causes movement of electrons, creating a current More than one cell, ie. panel is needed

Solar Energy Technology Thermal Collectors: use the sun's energy to heat water or another fluid such as oil or antifreeze. The panels are made from copper covered tubes, which have water passing through. Very costly and sun is not always out

Solar energy Renewable resource No greenhouse gases Can be used in isolated areas where there are no power lines ex. North or space

Moon The moon moves around the earth as well as it turns on owns its own axes Moon formed when a meteorite crashed into Earth and exploded pieces went into space

Tides Side of Earth facing moon changes throughout the day Moon exerts gravitational force and masses of water facing Moon are attracted to it

Tides Water balloons out and creates a bulge Water on other side of Earth is less attracted to Earth and balloons out too Causes high and low tides

Tides 2 high tides and 2 low tides per day Difference between high tide and low tide is known as amplitude and it varies depending on place and season Bay of Fundy- amplitude is 17 m Sun also has an affect on tides but much smaller

Tidal Energy Energy obtained using force of tides rising and falling Can convert to electrical energy Catch high tide water in basin and release at low tide Turns a turbine to transform to electrical energy

Tidal Energy Advantages No greenhouse gases produced Renewable Predictable Disadvantages Costly to install factories Factories must resist hostile conditions of oceans Few suitable sites Need 5 m amplitude minimum

In class work P.246 1,2,3,5,6,7,9