1. Cells of Power! Rhonda Hawley, Educator Developed with funding from The MathScience Innovation Center

2. What do leaves do for a tree?

3. Leaves collect sunlight and use it to make food for the tree.

4. An Average Leaf Looks Like This: But What If We...

5. Take a Look Inside a Leaf! http://kentsimmons.uwinnipeg.ca/16cm05/16labman05/lb4pg5.htm

6. These cells trap sunlight and convert it to chemical energy to make food for the tree. This is where the cells of power can be found

7. So the bigger the leaf... So the bigger the leaf..

8. The more sunlight that is trapped = more chemical energy to make more food... Right?

9. But wait, is size the most important thing to a leaf? What if it’s cloudy? Or something blocks the sun? Then, what can a leaf do to trap sunlight? But wait, is size the most important thing to a leaf? What if it’s cloudy? Or something blocks the sun? Then, what can a leaf do to trap sunlight?

10. Position! Position! Position!

11. What else can a tree or plant do to make the most energy/food possible?  Grow lots and lots of small leaves! -or- -or-  Grow a few really big leaves!

12. Take a Look at These Leaves  Which one makes the most energy/food?  Which leaf makes the least amount of energy/food?  How can we tell?  SURFACE AREA!

13. Count each whole box with an “X” What about the pieces of boxes? What about the pieces of boxes?

14. WWWWhen you calculate the area of a leaf, you discover the potential amount of solar energy that a leaf can collect. NNNNow, let’s compare the area of a man- made solar collector... Solar panels! They trap sunlight too!

15.  What do they do with the sunlight they collect?  Do they make food with that sunlight?  What do they do with the trapped energy?

16. Let’s Compare the Two! Leaves trap sunlight Leaves trap sunlight and convert it to and convert it to chemical energy to chemical energy to make their food. make their food. Solar panels collect Solar panels collect sunlight and convert sunlight and convert it to electrical energy it to electrical energy for us to use in our for us to use in our daily lives! daily lives! The solar energy collected by both trees and solar panels are considered to be renewable resources because the sun’s energy will not be used up for many lifetimes to come.

17. Take a Look Inside These Cells of Power!

18. Let’s Explore Those Solar Cells of Power!  Don’t forget about:  Position  Quantity  Surface Area

20. Credits:  Diagram of the Leaf found at University of Winnipeg: Evolution, Ecology and Biodiversity Online Lab Manual; Lab #4; Kingdom Plantae; The Leaf. http://kentsimmons.uwinnipeg.ca/16cm05/16labman05/index.htm http://kentsimmons.uwinnipeg.ca/16cm05/16labman05/index.htm  Still Photos of solar panels in slides 14 & 15 photographed by Ian Britton found at www.FreeFoto.com www.FreeFoto.com  Diagram used in slide 16, courtesy of U.S. Department of Energy; further information found at: http://encyclobeamia.solarbotics.net/articles/solar_cell.html http://encyclobeamia.solarbotics.net/articles/solar_cell.html  Still Photos of leaves taken by Rhonda Hawley and from on-line clip art file.  Video clip of Solar Cars found at http://www.discoveryeducation.com http://www.discoveryeducation.com