1. Allen High School IB Physics SL Source: Chris Hamper Physics

2.  Solar  Hydroelectric  Wind  Wave  This is the future of energy!  Let’s take a closer look....

3.  The Sun emits 3.90 x 10 26 J of energy PER SECOND!  The energy spreads out and by the time it reaches Earth (radius = 1.5 x 10 11 m), the Sun’s power is less intense.  Power per unit area ◦ 3.90 x 10 26 = 1380 W/m 2 -- This is the Solar 4π (1.5 x 10 11 ) 2 Constant ◦ The Sun’s energy is either absorbed or reflected. ◦ We use the Sun’s energy to either heat something or to make electricity.

4.  The amount of energy that reaches surface of the Earth depends on how much atmosphere it has to travel through.  Intensity depends on Latitude. The Sun shines through the least amount of atmosphere (most intense) when it is directly above (most atmosphere at sunset and sunrise = least intense).  Intensity also depends on the season; at different times of the year, since the tilt of the Earth varies throughout the year.

5.  Solar Heating Panel ◦ These are found on roofs of houses/buildings. ◦ Solar radiation is absorbed by the panel’s black metal plate, which then warms water by conduction. The warm water is then circulated.  Photovoltaic Cell (Solar Cell) ◦ Converts solar energy into electrical energy. ◦ Similar to a battery’s conversion of energy, except instead of chemical energy, it’s solar energy. ◦ The potential difference & current produced by one cell is small, therefore many cells are connected together.

6.  In a previous presentation, you learned that hydroelectric power originates with the Sun warming oceans; evaporation; clouds condensing; and then the rain falling has a high PE.  Note that height (in PE = mgh) would be the average height of the water.  This process can produce electricity.  Dams store energy in the form of water. Electricity is produced via generator when the water is released. (See picture on next slide)

8.  Windmills have been around for a while for a variety of purposes. Nowadays, we use them to generate electricity.  You learned previously that wind is caused by the Sun. The flow of warm air creates areas of different pressure, causing air to move = wind. The rotation of the Earth causes this wind to move in circular patterns.

9.  Coastal winds are caused due to different rates of heating of the land/sea.  We learned previously that water has a high specific heat and warms in day and releases at night. This air movement is wind.  Katabatic winds are formed when a high pressure is caused by cold air pressing down at the top of a mountain, resulting in a downhill airflow.

11.  Waves crashing ashore = energy transfer  There are surface waves (small) or rolling waves (originate out in ocean).  The energy of a wave alternates between PE as the water is lifted up and the KE as it falls.  This method is (as are the others) limited to the supply of waves consistently.

12.  A column half full of water. As water flows in, it compresses the air above pushing it through a turbine, which (if you haven’t guessed by now) generates electricity.  The turbine is specially designed so that as the water drops back down the column, the turbine also turns as it pulls air into the chamber.

14.  Renewable resources are usually nontraditional and more expensive in the beginning, but their benefits can have long- term effects.  The challenge of the future = Make non-traditional the new traditional!