2. Solar energy is one of the bountiful sources of energy on our planet. It is also one of the most clean source of energy available. It is completely sustainable because as long a we have the sun, we’ll have energy. Photovoltaic module is one of the prominent and efficient way to harness solar energy for usage. Photovoltaic is the direct conversion of light into electricity. Some materials exhibit a property that causes them to absorb photons of light and release electrons. when these free electrons are captured, electric current is produced. The overall phenomenon is term “photovoltaic effect”

3. Sun rays(photons of light) strike onto the solar cells or Photo- voltaic (PV) cells. The solar cells absorbed photons of light displacing electrons which begins to flow. In order to harness this flow, the electrons are drawn into magnetic field generated by positively- and negatively charged metal (n-type and p- type silicon) contacts on the top and the bottom of the cell.. thus, producing direct current.

4. The DC(direct current) is converted into AC(alternating current) in an inverter. The AC electricity is then supplied to the utility board(fuse box) in the house and is then evenly distributed to all electric section of the house. Excess solar energy can be collected and stored in a Battery as DC electricity. Alternatively, situations whereby there is more than enough solar energy, power can be exported into utility grid During night or overcast rainy days, utility grid supplies the exported power.

5. Collectively, we can build a simple solar cell in the lab Material Needed A copper sheet flashing( about o.5 square foot/0.05m2) Two alligator clip leads An electric cooler Table salt Sand paper A sensitive micro-ammeter that can read currents between 5 and 70 micro amps. A metal shear ( for cutting the copper sheet) A large plastic bottle.

6. Procedure washing your hands as well as the copper sheet properly with soap and water(sandpaper) to remove any grease or oil. Using the metal shear, cut the copper sheet that is about the size of your electric cooker. Place the copper sheet on the burner and set it to its maximum settings. When the copper starts heating up, some patterns red, orange, purple will be formed(oxidation).

7. When it gets hotter, the red, purple and orange colours will be replaced by a black coating of cupric oxide. The sheet of copper will be coated with a black cupric oxide completely. Heat it for about 30 minutes more so that the coat will be thick. Note A thick coat will flake off easily while a thin coat will stay stuck to the copper. After 30 minutes of heating, turn off the cooker and allow the copper to cool slowly on the cooker. If you decide to cool it quickly, the black oxide will be stuck to the copper.

8. The copper sheet will shrink as it cools. The black cupric oxide will also shrink but they will shrink at different rate, thus enabling the black coat flake off. When the copper has cooled to room temperature(about 20 minutes), most of the black oxide will be gone. A light scrubbing with my hands under running water will remove most of the small bits. note- Don’t remove the black spot by hard scrubbing of flexing the soft copper. This might damage the delicate red cuprous oxide layer that we need to make the solar cell work.

9. Cut another copper sheet about half-sized the first one. Bend both pieces gently so that they will fit into a plastic bottle or jar without touching one another. The cuprous oxide coating that was facing up on the burner is usually the best side to face outward in the jar because it has the smoothest, cleanest surface. Attach the two alligator clip lead, one to the new copper plate, and the other to the cuprous oxide coated plate. Connect the lead from the clean copper plate to the positive terminal of the meter. Connect the lead from the cuprous oxide to the negative terminal of the meter.

10. Now mix a couple of the salt into some hot tap water. Stir the saltwater until all the salt is dissolved. Carefully pour the salt water into the jar, being careful not to get the clip lead wet. The salt water should not completely cover the plates. You should leave about an inch of the plate above the water so you can move the solar cell around without getting the clips wet.

11. The cell will produce about 40 – 50amps (that’s about 12.5 microwatts). Hence, the device will not light a bulb or charge batteries Since 0.05 meter square 0r 1 meter square will produce 0.0000125microwatts or 1.25milliwatts respectively, lighting a 100 watts bulb will take about 80,ooo meter square (100/0.0000125). I would need acres of them to power a house.

12. The cost of half square meter sheet to be used is about $ 2. Note- 0.01 meter square 0.0000125 watts 800meter square 1 watt since 0.0000125 watts $ 2 1 watt $ 160, 000 Silicon solar panel only cost $ 4 to produce 1 watt

13. Chapter 3-Electrochemistry, scitoys.com building your own solar battery Ron Curtis and mrsolar.com How to build a solar cell, www. Ehow.com