1. Introduction

Since the industrial revolution, we have attempted to use electrical energy to satisfy our

needs. This enormous energy consumption rules over the performance of our companies and

our economy in general. For this, we tried to find other sources that can serve our industry

with less wastes and less pollution. Among these sources, there is the photovoltaic energy,

which was discovered in 1839 and it represents the most suitable energy sources in our days.

So what is photovoltaic energy? What are its scientific bases? Moreover, what are its effects

on our economy?

2. Definition and physical Phenomenon

What is solar energy?

Solar energy is an energy source, which depends on the sun .This energy enables the

production of electricity from photovoltaic panels or solar thermal power plants, with sunlight

captured by solar panels.

What is a photovoltaic solar panel?

The photovoltaic effect was discovered in 1839 by the French physicist "Antoine Becquerel".

A solar panel operates by the photovoltaic, which consist of creating an electromotive force

due to the absorption of light energy in a solid object.This is the only way presently known to

directly convert light into electricity. The photovoltaic cell is the basic element of solar

photovoltaic panels. This is a silicon-based semiconductor device supplying a voltage of the

order of ? 0.5 to 0.6 V.

Antoine Becquerel

1788 - 1878

1. Photons in sunlight hit the solar panel and semiconducting materials, such as silicon, absorb them.

2. Electrons (negatively charged) are knocked loose from their atoms, allowing them to flow through the material to produce electricity.

3. An array of solar cells converts solar energy into a usable amount Of direct current

(DC) electricity

Operation of the photovoltaic effect

3. Solar Panel Manufacturing Technologies:

Mono-Si Panels Poly-Si Panels Thin Film Panels

1. Most efficient with max. Efficiency of 21%.

1. Less efficient with efficiency of 16% (max.)

1. Least efficient with max. Efficiency of 12%.

2. Manufactured from single Si crystal.

2. Manufactured by fusing different crystals of Si.

2. Manufactured by depositing 1 or more layers of PV material on substrate.

3. Performance best at standard temperature.

3. Performance best at moderately high temperature.

3. Performance best at high temperatures.

4. Requires least area for a given power.

4. Requires less area for a given power.

4. Requires large area for a given power.

5. Large amount of Si hence, high embodied energy.

5. Large amount of Si hence, high Embodied energy.

4. Low amount of Si used hence, low embodied energy.

6. Performance degrades in low-sunlight conditions.

6. Performance degrades in low-sunlight conditions.

5. Performance less affected by low-sunlight conditions.

7. Cost/watt: 1.589 USD 7. 1.418 USD 7. 0.67 USD

8. Largest Manufacturer:Sunpower (USA)

8. Suntech (China) 8. First Solar (USA)

4. Fields of applications:

Photovoltaic panels are mainly used to power satellites in energy, within the domestic

framework in industries and in means of transport.

5. PV installations:Most residential homes using PV technology are still linked to the Utilities power grid

other option is storing excess generated energy in battery unit so no alternate source

available then

a) Off grid system: ( stand alone):

Stand-alone PV systems are designed to operate independent of the electric utility grid, and

are generally designed and sized to supply certain DC and/or AC electrical loads.

Common applications are direct power to DC loads, water pumping and

telecommunications.

With an inverter it can also power AC loads

For systems with no battery the energy is used immediately; only works when it's

sunny .

Systems with Battery Backup can supply power 100% of the time:

At night, on cloudy days and when the utility power is down

First car with solar energy (1983)

First boat with solar energy

b) Grid Tie – Grid Connected Systems

Grid Tie System is the simplest and most cost effective way to connect PV modules to

regular utility power.

Grid-Connected systems can supply solar power to your home and use utility power as

a backup. As long as there is enough electricity flowing in from your PV system, no

electricity will flow in from the utility company.

If your system is generating more power than you are using, the excess will flow back

into the grid, turning your meter backwards.

6. solar energy effects on the economy:

There are many more ways solar energy benefits the economy, directly and indirectly. By

reducing your home’s use of traditional energy sources, you help keep natural ecosystems

intact, reducing tax payer funded clean-ups and potentially devastating oil spills like the

recent BP disaster along the Gulf Coast. If your photovoltaic solar panels generate more

energy than your home uses, you can sell back energy to your local utility company, leaving

more money in your pocket to spend at restaurants, movie theaters, or financial investments.

As a whole, the solar energy industry grew a total of 67% between 2009 and 2010. Nationally,

solar energy is now responsible for over 100,000 American jobs, in over 5,000 businesses

in every state. These workers are primarily employed by small to middle-size companies in

local communities. Many of these companies are able to take advantage of tax credits for new

hires as well. in Maryland, the state is offering $5,000 for new hires in the field of renewable

energy. This explosive growth has helped spur the creation of new jobs and provided

employment for various companies involved in the renewable energy industry.

An example of domestique PV installations

7. conclusion:

At the end we conclude this presentation by confirming that solar energy is a suitable solution

for the world energy problems considering the fact that it’s a renewable source of energy,

available at any place or time and it doesn’t affect the environment in a negative way.