Question

A summary of the ways in which solar power can be exploited including its various advantages and disadvantages and an explanation of the differences in structure and mechanism between LED and Photovoltaic cells.

Answer 1

Advantages

1. Solar power is pollution free and causes no greenhouse gases to be emitted after installation.

2. Reduced dependence on foreign oil and fossil fuels.

3. Renewable clean power that is available every day of the year, even cloudy days produce some power.

4. Return on investment unlike paying for utility bills.

5. Virtually no maintenance as solar panels last over 30 years.

6.Creates jobs by employing solar panel manufacturers, solar installers, etc. and in turn helps the economy.

7. Excess power can be sold back to the power company if grid intertied

8. Ability to live grid free if all power generated provides enough for the home / building.

9.Can be installed virtually anywhere; in a field to on a building

10. Use batteries to store extra power for use at night.

11. Solar can be used to heat water, power homes and building, even power cars.

12. Safer than traditional electric current.

13. Efficiency is always improving so the same size solar that is available today will become more efficient tomorrow.

14. Aesthetics are improving making the solar more versatile compared to older models; i.e. printing, flexible, solar shingles, etc.

15.Federal grants, tax incentives, and rebate programs are available to help with initial costs

Disadvantages

1. High initial costs for material and installation and long ROI.

2.Needs lots of space as efficiency is not 100% yet.

3.No solar power at night so there is a need for a large battery bank.

4. Some people think they are ugly (I am definitely not one of those!)

5.Devices that run on DC power directly are more expensive

6. Depending on geographical location the size of the solar panels vary for the same power generation.

7. Cloudy days do not produce much energySolar panels are not being massed produced due to lack of material and technology to lower the cost enough to be more affordable.

9. Solar powered cars do not have the same speeds and power as typical gas powered cars.

10. Lower production in the winter months
Diodes are semiconductor devices that allow current to flow in only one direction. Diodes act as rectifñers in electronic circuits, and also as efficient light emitters (in LEDs) and solar cells (in photovoltaics). The basic structure of a diode is a junction between a p-type and an n-type semiconductor, called a p-n junction. Typically, diodes are made from a single semiconductor crystal into which p- and n- dopants are introduced

Figure 10.6.X: Current-voltage characteristic ofa solar cell in the dark and under illumination with band gap light. The short-circuit photocurrent is indicated as isc, and the open-circuit photovoltage is Vphoto. The maximum power generated by the solar cell is determined by the area of the orange box. Photocurrent in p-n junction solar cells flows in the diode reverse bias direction. In the dark, the solar cell simply acts as a diode. In the light, the photocurrent can be thought of as a constant current source, which is added to the i-V characteristic of the diode. The relationship between the dark and light current in a photovoltaic cell is shown in the diagram at the left.