1. Presented to you by: Chin Ming Fwu (2i3’03) Gaw Ban Siang (2i3’06) Kyle Foo (2i3’09)

2.  What is photovoltaics?  Video =D  Scientific explanation  Examples…  So why it this a better choice?  Statistics & Benefits

3. What are photovoltaic cells? How do they actually generate electricity?

4.  “Green” source of energy  Using the sun’s energy to convert into electricity for our own usage.

5.  Converting light directly into electricity  Done at the atomic level Absorb photons of the light Release electrons Electrons Captured The resulting electric current is then used as electricity.

6.  Many photovoltaic cells are arranged together to form an array, or a “solar panel”.  Can be used to generate electricity.

8.  N-type and P-type silicon come into contact.  Free electrons in N-type silicon attracted to the positive ions in the P-type silicon.  At the junction between the free electrons and the positive ions, an electric barrier is formed.  Acts as a diode, allowing electrons to travel from the P-type silicon to the N-type silicon but not N- type to P-type.

9. N-type P-type Electric Barrier

10.  When photons hit the solar cell, electrons will be dislodged and sent from the N-type to the P- type silicon, causing a disruption of electrical neutrality.  If there is an external current path such as a wire, the electron will flow from the N-type to the P-type and as such a current is created.

11. N-type P-type Current Electron Dislodged by photon

12. Let us watch a short video to learn more!

13.  CLICK HERE (: CLICK HERE (:

14. How is solar energy utilised in our daily lives?

15.  Can you think of some examples of the usage of solar energy in our society? ^^

16. Solar-Powered Cars Technology has allowed us to use solar energy to power up our cars. No need to rely on toxic petrol and natural gases. No carbon emissions, no global warming.

17. Solar-Powered Toys Solar Panels have also been installed in our toys. Able to move by itself once put under bright sunlight. Better as compared to the traditional toys Safe for environment.

18. Voltaic Backpack Even our backs can absorb energy from the sun. Can be used to charge mobile phones and iPads when they are put into the backpack.

19. Solar-Powered School Schools & buildings usually need the most electricity. Lights, air conditioners and fans are turned on for almost the whole day. Redding, CA Elementary School

20. Solar-Powered Traffic Light Turned on the entire day (everyday) to coordinate traffic. Portland started using such lights, and: Before (installation)After (installation) Kilowatt hours per year 6.1 million1.2 million Electric cost per year $420,000$85,000 Energy savings per year $335,000

21. Yes. Even we are using solar energy to our advantage.

22.  Hwa Chong has a long-lasting tradition  Using lights to brighten up the clock tower every night, throughout the night.  However…  Conventional Electricity does not work out  Pollutes the environment  Costly

24. Why should we bother to choose solar energy over conventional forms?

25.  Reduces utility bill by up to 70%.  Money used to buy the system can be recouped in only about 10 years.  Do not require much maintenance.  Can last up to 40 years  Warranty of about 25 years (on avg).  Unlimited supply of solar energy  Hedge against price instability and fluctuation

26.  Cost of solar energy usage will reach grid parity by Year 2014 (Inglin, 2010)  Cost if solar panel installation going down  Cost of conventional electricity – steady increase  2010 – $5 per watt peak 2014 – $3 per watt peak  (equal to utility bills of conventional electric use)  Price has decreased sevenfold in only 20 years.

27.  Renewable, clean & abundant in Singapore  Production of solar energy  ZERO carbon emissions  ZERO pollution  Sun’s energy is (theoretically) unlimited  Can be harnessed forever  Unlike fossil fuels, which we are depleting too fast

28.  Only a thin sheet of silicon and other photovoltaic materials.  Put on rooftops like a cover  Not bulky at all.  Unlike the traditionally huge power stations to burn the fossil fuels.  (Only applies to small-scale domestic use)

29.  The cost price – takes about $20,000 to get a photovoltaic cell system.  However…  The price is decreasing steadily due to rapid advancements in technology.  Even now, it can be earned back within 10 years.

30.  Solar Power helps us in many ways:  Cost - Efficient  Space – Saving  Environmentally – Friendly  Use Solar energy! (:

31. Please, please, please visit!

32.  Our Website (20112i3photovoltaics.wiki.hci.edu.sg) Our Website  Contains more in-depth information and examples of solar-energy usage  Japan – Domestic Usage  Googleplex