Science & Technology Time!

Graham and Parks School
"Okay"-Room 201

May 22, 2003
by 
Ali Taalebinezhaad, PhD

Renewable and Sustainable Energy Sources

In the last session, we saw how an  "Internal  Combustion Engine"  uses gasoline and air  to produce energy for running a car. There are three main problems with this kind of energy production:

1. The source of such energy, namely gasoline (oil), is limited and we will run out of it in near future.
2. It is not free! You should pay for it dearly because as a consumer you do not have any control on its price.
Oil companies increase their prices with any excuse that they can  find and keep the price high as long as they can.
3. It pollutes the environment and adversely effects the human, nature, and animals.

So what are the alternatives to oil which do not have those bad side effects?
The answer is Renewable or Sustainable Energy Sources such as Wind,  Sun, and Water!

Wind Energy:
The wind turns the blades (fan) which are connected to a machine which produces electricity by spinning. 
These machines are called "Wind Turbines". The generated electricity can then be used for running our electrical devices right away or can be stored in rechargeable batteries for future use. Did you know that Cape Cod, Massachusetts  is currently studied for having a huge wind farm (a set of wind turbines)?

Water Energy:
We can also use the flow of water in the rivers for producing electricity.
The water flow turns the blades of such machines which are called "Water Turbines".
These spinning machines then produce electricity.

Solar Energy:
Not everyone has easy access to a good river or wind for producing energy but we all have the sun!
Solar energy is one of the best sources of energy which is not going to finish anytime soon!
We have access to it not only on the earth but also any where else in our solar system universe!
NASA used solar energy to energize the the Rover on the surface of the Mars in one of its missions.
International Space Station uses solar energy for producing its electricity needs.
If they can use it in space we can definitely use it on earth! And that is what people are doing now.

The device which is used for converting the solar energy to electricity is called "Solar Cell". 
The main component of  a solar cell is silicon (Si) and is obtained from sand which is safe and cheap!
The process which converts sunlight into electricity is called "Photovoltaic" or simply PV.
        Photo  = light
        Voltaic = produces voltage (electricity).
A set of solar cells are connected together to produce a "Solar Panel"!
People installsolar panels on their roof and produce electricity for free!
Organizations such as MIT and the White House have also used solar panels for producing some of their electricity needs.

A message to take home with you!
When you get home ask your Mom or Dad this:
    "Do we have any device which runs on solar energy at home?"

Want to learn more?
Go to PhotoVoltaic Tutorial if you want to learn more about "Solar Cells" and "Photovoltaic".
    

Answer the "Questions of the Week" to Enter the LOTTERY!


If you want to win a nice prize, this is what you need to do:
0. Read your handout about "Renewable and Sustainable Energy Sources"!
1. Go to http://web.mit.edu/taalebi/www/scitech/lottery.htm
2. Read the "Questions of the Week".
3. Write down your name and answers on the attached answer sheet.
4. Bring your answer sheet to the class next Thursday.
5. Fold your answer sheet THREE times and drop it in the lottery bag for a drawing!

 


Visit your NEW web site for "Science &  Technology Time" at
    http://web.mit.edu/taalebi/www/scitech
where you can find your photos, handouts, and more.
Please send your comments and questions to: taalebi@ai.mit.edu