THE SUN:THE SUN:Solar EnergySolar Energy

The Sun as a StarThe Sun as a Star It’s light is the major source of energy for It’s light is the major source of energy for

all planets and life on Earth.all planets and life on Earth. It’s an “average” starIt’s an “average” star4.5 billion years old – ½ way through life 4.5 billion years old – ½ way through life

cyclecycle

http://www.solarviews.com/images/VSS00031.jpghttp://www.solarviews.com/images/VSS00031.jpg

Sun Sun LayersLayers

1. Core = 1. Core =

14,500,000 K14,500,000 K

2. Radiative Zone = 2. Radiative Zone = 2,100,000 K2,100,000 K

3. Convection Zone = 3. Convection Zone = 1,000,000 K1,000,000 K

4. Photosphere = 6,000K4. Photosphere = 6,000K

5. Chromosphere = 5. Chromosphere = 27,000 K27,000 K

6. Corona = 6. Corona = 2,000,000 K2,000,000 K

7. Sunspots = 5,000 K7. Sunspots = 5,000 K

8. Granules8. Granules

9. Solar Prominence 9. Solar Prominence

Sun: A Nuclear ReactorSun: A Nuclear ReactorThe Sun does not “burn” like wood.The Sun does not “burn” like wood.The Sun is made of:The Sun is made of:

78% Hydrogen78% Hydrogen20% Helium20% Helium2% heavier elements2% heavier elements

Because it’s so large, the gravity is very Because it’s so large, the gravity is very strong. So, deep inside the temperature strong. So, deep inside the temperature and pressure are very high.and pressure are very high.

Sun: A Nuclear ReactorSun: A Nuclear Reactor (con’t) (con’t)Nuclear FusionNuclear Fusion: the process where : the process where

Hydrogen atoms fuse together to make a Hydrogen atoms fuse together to make a Helium atom (H + H = He) …it’s not that Helium atom (H + H = He) …it’s not that simple, however..simple, however..

http://www.ustudy.in/node/3161

This is a This is a nuclear nuclear reactionreaction and it and it releases energy in releases energy in the form of heat and the form of heat and light.light.

Ways Heat Energy can be Ways Heat Energy can be TransferredTransferred

1.1. ConductionConduction: Heat energy transferred by : Heat energy transferred by contact. Energy from a higher energy contact. Energy from a higher energy atom or molecule gets passed on to one atom or molecule gets passed on to one with less energy when they bump into with less energy when they bump into each other.each other.

Ways Heat Energy can be Ways Heat Energy can be TransferredTransferred (con’t) (con’t)

2. 2. ConvectionConvection: heat energy transferred by : heat energy transferred by movement of a liquid or gas. As warm movement of a liquid or gas. As warm air gains heat energy, it becomes less air gains heat energy, it becomes less dense and rises. Cooler air sinks.dense and rises. Cooler air sinks.

Ways Heat Energy can be Ways Heat Energy can be Transferred Transferred (con’t)(con’t)

3. 3. RadiationRadiation: Heat energy transferred : Heat energy transferred through space. through space.

It’s how Solar energy travels to Earth. It’s how Solar energy travels to Earth.

Ways Heat Energy can be Ways Heat Energy can be TransferredTransferred – all in one! – all in one!

Draw a simplified diagram of this and label the types of heat transfer.

http://blogs.saschina.org/morena01pd2016/files/2009/10/ccr.jpg

Solar EnergySolar EnergyEnergy comes in many forms, such as Energy comes in many forms, such as

heat and light. heat and light. Solar energy (energy from the Sun) travels Solar energy (energy from the Sun) travels

through space as an electromagnetic through space as an electromagnetic wave.wave.

http://www.warren-wilson.edu/~physics/physics2/Formal2000/sstephens/elecmag.gif

Electromagnetic RadiationElectromagnetic Radiation

The Sun gives off these types of light in varying amounts. Radio The Sun gives off these types of light in varying amounts. Radio waves have the longest wavelength & least energy, Gamma Rays waves have the longest wavelength & least energy, Gamma Rays have the shortest wavelength & the most energy. All of these travel have the shortest wavelength & the most energy. All of these travel at 300,000 km/sec in space. at 300,000 km/sec in space.

http://www.fluxnet-canada.ca/pages/pics/Electromagnetic_spectrum.png

Electromagnetic RadiationElectromagnetic Radiation

http://asd-www.larc.nasa.gov/erbe/components2.gif

Solar Energy =Solar Energy =Electromagnetic RadiationElectromagnetic Radiation

The 2 main types ofThe 2 main types of solar radiation solar radiation (aka Electromagnet radiation)(aka Electromagnet radiation) are heat are heat (aka infrared rays)(aka infrared rays) and and light (aka visible light (aka visible light).light).

The Sun also gives off some UV light (7%) The Sun also gives off some UV light (7%) and a tiny amount of radio waves, and a tiny amount of radio waves, microwaves, X-rays, Gamma rays.microwaves, X-rays, Gamma rays.