Saved By the Sun
Got Sun? Get Cooking!
According to the World Health Organization (WHO),
between 2 million and 5 million people—many of them children in
developing countries—die each year from diseases resulting from
contaminated water. Your team has been hired by WHO to help solve this major
world health crisis. Your challenge is to design the most efficient,
inexpensive, portable solar cooker that will attain a temperature needed to
pasteurize contaminated water and make it healthy to drink.
Criteria for Success
The effectiveness of your cooker will be judged by
- its efficiency (pasteurizing water the
- its cost-effectiveness (uses inexpensive
- its portability (can be easily transported
from one place to another)
Follow the steps on your "Invention Checklist" handout as you
design, build, and test your solar cooker.
As you test your first design, use the
"Temperature Data" handout to record your data. When you have
finished testing your first design, plot your data on the graph supplied on
your student handout.
Present your first cooker to the class and add
your temperature data to the class chart. Each team will present its cooker and
Choose a variable (or variables) to change on
your design for your second model. Note on your original drawing what you
changed and include a list of reasons why in your journal.
Test your second model and enter the new
temperature data on the graph on which you plotted your first data set.
Write your answers on a separate sheet of
Based on your data, was your first model or
your redesigned model more efficient at heating the water?
What factors do you believe accounted for the
differences in the efficiency of the two solar cooker designs?
List three variables that affect the time it
takes to heat water in a solar cooker.
Draw a diagram to show how
transmission, reflection, absorption, and insulation played a part in your
solar cooker (depending on your type of cooker not all of these concepts may
If you had to change one design element in your
cooker to improve it for a subsequent test, what would it be? Why would you
make the change?
Compare the use of the sun as an energy source
to one of the following types of energy sources: wood, fossil fuels such as
coal or oil, nuclear power, wind, or water.