1. Solar Energy

2. What idea is the artist trying to convey in this cartoon?
What are some of the potential benefits of solar energy compared to traditional energy sources like fossil fuels?

3. Where does the Sun get it’s energy?
Watch….

4. Solar Energy
Electromagnetic energy from the sun comes to Earth in the form of radiation.
The term "radiation" simply denotes the fact that the energy travels as rays, that is, in straight line.
In general, the terms "solar energy" and "solar radiation" simply refer to energy from the Sun.
Electromagnetic energy is characterized by the property that it is pure energy, not requiring any matter (or medium) for its existence or movement.
Electromagnetic energy can therefore travel through space (which is a vacuum), traveling at a speed that is the same for all forms of electromagnetic energy and is equal to the speed of light, (3 x 108 m/sec or 1,079,252,848.8 km/h).

5. Solar Energy
The sun radiates energy equally in all directions, and the Earth intercepts and receives part of this energy.
The range of electromagnetic energy emitted by the sun is known as the Solar spectrum, and lies mainly in three regions: ultraviolet (UV), visible light, and infrared. (There is a small amount of high-energy radiation like x-rays in the sun's energy but these do not penetrate below the topmost layer of the atmosphere.
The majority of solar energy comes in the form of "light" and "heat" in the visible and infrared regions of the electromagnetic spectrum.

6. What about other stars?
·The range of energy given off by a star depends upon the temperature and size of the star.
Smaller, hotter stars (called white dwarfs") give off more energy in the blue region and appear "whiter" than our yellow sun. Rigel, a star in the constellation Sirius, is a white dwarf.
· Larger, cooler stars, called "red giants," emit more light in the red region, and are exemplified by Antares and Betelgeuse. Note that even a "cool" star still has a temperature of a million degrees or so.

7. Earth’s Energy Budget
Complete the questions on your sheet to analyse how much of the sun’s energy reaches the surface of the Earth.

8. Answer Key for Earth’s Energy Budget
ANALYSIS QUESTIONS: %
2.Some is immediately reflected back into space by clouds and the atmosphere itself.
3. Clouds, ice, and snow increase the amount of solar radiation that is reflected.
4. Six percent is reflected and 16 percent is absorbed.
5. Geographic location, time of day, season, local landscape and weather.

9. Canada’s Solar Potential
According to the International Energy Agency (IEA), 99% of Canada’s cumulative PV (photovoltaic) power capacity of utility-connected systems is in Ontario.
What part of Canada receives the most Solar Energy?
Southern Alberta and Saskatchewan
What part of Canada receives the least Solar Energy?
Northern Nunavet

10. How can we harness solar energy: 2 main methods
1. Concentrating Solar Power
Large curved mirrors are used to reflect sunlight from a large area and focus it on a much smaller area.
Solar power plants use computer-controlled sun-tracking mirrors which move to face the sun’s rays. The sun’s thermal energy is reflected and focused on a large water boiler often on a tower. The fluid boils to produce steam which drives a turbine to generate energy.

11. How can we harness solar energy: 2 main methods
2. Photovoltaic Cells
Solar cells called photovoltaic (PV) cells convert sunlight energy into electricity.
Semiconductor materials absorb sunlight energy and create an unbalanced flow of electrons from one side of the solar cell to the other.
The sides are connected with a metal material which allows the electrons to travel. The flow of electrons produces electricity.