1. 1.4 Renewable Electrical Energy Design
Simon Ray, Jesse Ardila, and Gabe Lillard
POE Period 1
McKinney High School
11/21/2014

2. Research and Design
Our team found that the LEDs interact with the power supply differently depending on whether the circuit was wired in series or parallel. By consulting our notes we found that this can be attributed to Kirchhoff's Circuit Laws.
Our research online as well as in class showed us that a single LED will require around 2.1 volts to function in a satisfactory manner while wired with the 330 ohm resistor
These 2 facts proved to be very important in the determination of the final design
In an attempt to save power, our group initially agreed on a parallel circuit whose LEDs could be disconnected from the circuit by switches so as not to draw power from the power sources. However, we quickly found that we were constrained by our switch parts as they did not function as expected.
We circumvented this power issue by improving our turbines gear train and wheel system so that the switches would not be necessary. After modifying we realized that turbine itself provided sufficient power to meet the constraints.
This led to a simplification of the design which included only the turbine and LED banks

3. Design Brief Client: City of McKinney
Designers: Jesse Ardila, Simon Ray, Gabe Lillard
Problem Statement: The city of McKinney is expanding at a high rate, and so are it’s energy needs. McKinney faces brownouts and energy restrictions as it’s infrastructure is not meet power demand.
Design Statement: Design, prototype, and test a renewable energy system which may harness wind as well as solar power in order to meet the energy needs of the city of McKinney.
Constraints: Allowable electrical energy generation devices
2 Solar cells
2 Fuel cells
Wind turbine(vex motor)
LEDs must be wired in two separate banks
LEDs must be wired in series with a 330 ohm resistor

4. Brainstorming Sketches
All 5 sketches are variations
on similar designs and
concepts

5. Wiring Diagram

6. Final Solution Sketch (picture)

7. Prototype -Unnecessary components removed
-Consists solely of turbine and LED banks
Turbine: 60 tooth gear (driving) meshed
With 12 tooth gear (driven), producing a
gear ratio of 1/5
5 red LEDs wired in series (in an individual
bank)
3 amber LEDs wired in series (also in a
separate bank)
2 330 ohm resistors (a resistor is
wired with each bank)
Test results: This prototype was able to successfully power all LEDs without frequent
blackouts or brownouts for the entirety of testing.
The presence of a wheel on each side of the machine proved to be the most important
component for providing consistent power.

8. Works Cited MyPLTW Documents
Oldham, Kalil T. Swain (2008). The doctrine of description: Gustav Kirchhoff, classical physics, and the "purpose of all science" in 19th-century Germany (Ph. D.). University of California, Berkeley
Anthony C. Fischer-Cripps (2004). The electronics companion. CRC Press
John Rounce, Calculations for A-level Physics, p. 2, Nelson Thornes