1. Can We ‘Grow’ Electricity?!
Group #1 ★
Can We ‘Grow’ Electricity?!
Zhi Wei Ngion, Tiffany Park, Leo Siha, Amy Wan, Sherry Zhang

2. ★ Introduction Generating power produces
Pollution
Global warming
Lemon and potato as power sources:
Clean
Renewable
Biodegradable

3. ★ Physics Experiment Voltage output of lemon & potato batteries
How time affects the battery’s effectiveness

4. ★ Physics Data Presentation Experiment I day 1 day 2 lemon
voltage ± 0.001V
Voltage ± 0.001V 1
0.985
0.993 2
0.990
0.951 3
0.973
0.989 4
1.000
0.963 5
1.008
0.950
Average
0.991
0.969

5. ★ Physics Data Presentation Potato Voltage ± 0.001V #1 0.808 0.743 #2
0.895
0.814 #3
0.928
0.794 #4
0.938
0.940 #5
0.992
0.857
Average
0.912
0.830

6. Physics ★
Conclusion
Lemon batteries’ potential difference (voltage output) are relatively larger
Average potential difference (voltage output) of the batteries decrease as time increases

7. ★ Chemistry Oxidation-reduction (redox)
How do lemon batteries create electricity?
Oxidation-reduction (redox)
These reactions involve the transfer of electrons between substances.
Redox reactions release energy, and this energy can be used to do work if the reactions take place in a voltaic cell.

8. ★ Chemistry Standard Electrode Potentials
The cell potential is a measure of the difference between the two electrode potentials.
The standard electrode potentials, Eo , in aqueous solutions of Cu and Al are and –1.66 V with reference to hydrogen H.
The cell voltage of the ”lemon battery” is the “difference”,
U = (+0.34) – (-1.66) = 2 V.

9. ★ Chemistry Experiment
To investigate the relationship between the acidity of the lemon and its voltage output.

10. ★ Chemistry Data Presentation Experiment II China Voltage ± 0.001 V
pH ± 0.1
Thailand 1
0.961
3.0
0.948
2.8 2
0.991
2.9
0.976 3
0.505
0.517 4
0.947 5
0.964
3.3
0.955 6
Average
0.869 7
0.969
3.1 8
0.940
3.2 9
0.957 10
0.916

11. Chemistry ★
Data Presentation

12. Chemistry ★
Data Presentation

13. Chemistry ★
Conclusion
UNABLE TO PROVE: Linear relationship between voltage and acidity
The conditions of the electrodes will affect the voltage of the battery

14. Biology ★
Experiment
To investigate the geographic origins & mass of the lemons.
Also the relationship of the mass of lemon with its voltage output.

15. ★ Biology Data Presentation Lemons from the USA Mass ± 0.1g Voltage
pH ± 0.1 1 g
0.907
3.0 2 g
0.946
2.9 3 g
0.914 4 g
0.906
Average g
0.918

16. ★ Biology Data Presentation Lemons from China Mass ± 0.1g Voltage
pH ± 0.1 1 g
0.969
3.1 2 g
0.940
3.2 3 g
0.957 4 g
0.947
Average g
0.953

17. Biology ★
Data Presentation

18. Biology ★
Data Presentation

19. ★ Biology Conclusion Both sets of data are randomly scattered
Mass does not effect the voltage output of the lemons

20. Conclusion and Evaluation★
Physics
Statistic values
20W light bulb
2.5 mg of coal (1 second)
2.5 kg of coal (11.5 days) cost: 2.5 RMB
108 lemons can provide the amount of voltage to power 27 LED
The light energy given out by 27 LEDs equals to 120W light bulb
234 lemons can provide the amount of voltage to power 120W light bulb
108 lemons (from mainland China) cost 216 RMB

21. Conclusion and Evaluation★
Physics
Effectiveness of lemon batteries
Individually and in groups
Time factor:
Lemons biodegrade
Lemon battery
Voltage ± 0.1V
Series of batteries 1
0.9
2.1 2 3
0.7
Total voltage
2.5

22. Conclusion and Evaluation★
Chemistry
Effects of electrodes on the lemon battery
- Surface oxidation
- Electrochemistry potential
Substance
Standard electrode potential
Lithium
﹣3.04
Magnesium
﹣2.37
Aluminum
﹣1.66
Zinc
﹣0.76
Iron
﹣0.44
Copper
＋0.34
Silver
＋0.80

23. Conclusion and Evaluation★
Chemistry
Economic costs for the electrodes
Effects of acid in lemon on the electrodes
- Corrosion of metal
Requirements for the redox reaction
Must be electrically connected
Could be provided by just the lemon juice
Metals
Cost (RMB per ton)
Magnesium
15.4 thousand
Aluminum
15.3 thousand
Copper (electrolyze)
59.0 thousand
Zinc
16.4 thousand

24. Conclusion and Evaluation★
Biology
Lemons can be genetically altered to become smaller in size therefore more space efficient
lemons are only able to bear fruit year round when grown in mild climate
Transportation of lemons
Areas to mass produce lemons 1. Building Greenhouses 2. Opening more areas for plantation 3. Not enough space
Effect of mass production of lemons on other plantation
Use of water

25. Conclusion and Evaluation★
Biology
Not enough lemons  affected accuracy of data
1. Variety of sizes
2. Variety of locations
Time
1. Grow lemons under different conditions (e.g. soil pH)

26. ★
Thank You!