Solar energy in one form or another is the source of nearly all energy on the earth.
Humans, like all other animals and plants, rely on the sun for warmth and food. However,
people also harness the sun's energy in many other different ways. For example, fossil fuels,
plant matter from a past geological age, is used for transportation and electricity generation
and is essentially just stored solar energy from millions of years ago. Similarly, biomass
converts the sun's energy into a fuel, which can then be used for heat, transport or electricity.
Wind energy, used for hundred of years to provide mechanical energy or for transportation,
uses air currents that are created by solar heated air and the rotation of the earth. Today wind
turbines convert wind power into electricity as well as its traditional uses. Even
hydroelectricity is derived from the sun. Hydropower depends on the evaporation of water by
the sun, and its subsequent return to the Earth as rain to provide water in dams. Photovoltaics
(often abbreviated as PV) is a simple and elegant method of harnessing the sun's energy. PV
devices (solar cells) are unique in that they directly convert the incident solar radiation into
electricity, with no noise, pollution or moving parts, making them robust, reliable and long
lasting. Solar cells are based on the same principles and materials behind the communications
and computer revolutions, and this CDROM covers the operation, use and applications of
photovoltaic devices and systems.
Solar energy is the most readily available source of energy. It does not belong to
anybody and is, therefore, free. It is also the most important of the non-conventional sources
of energy because it is non-polluting and, therefore, helps in lessening the greenhouse effect.
Solar energy has been used since prehistoric times, but in a most primitive manner. Before
1970, some research and development was carried out in a few countries to exploit solar
energy more efficiently, but most of this work remained mainly academic. After the dramatic
rise in oil prices in the 1970s, several countries began to formulate extensive research and
development programmes to exploit solar energy.
When we hang out our clothes to dry in the sun, we use the energy of the sun. In the
same way, solar panels absorb the energy of the sun to provide heat for cooking and for
heating water. Such systems are available in the market and are being used in homes and
1.1 Current Scenario
In the next few years it is expected that millions of households in the world will be
using solar energy as the trends in USA and Japan show. In India too, the Indian Renewable
Energy Development Agency and the Ministry of Non-Conventional Energy Sources are
formulating a programme to have solar energy in more than a million households in the next
few years. However, the people’s initiative is essential if the programme is to be successful.
India is one of the few countries with long days and plenty of sunshine, especially in
the Thar desert region. This zone, having abundant solar energy available, is suitable for
harnessing solar energy for a number of applications. In areas with similar intensity of solar
radiation, solar energy could be easily harnessed. Solar thermal energy is being used in India
for heating water for both industrial and domestic purposes. A 140 MW integrated solar
power plant is to be set up in Jodhpur but the initial expense incurred is still very high.
Solar energy can also be used to meet our electricity requirements. Through Solar
Photovoltaic (SPV) cells, solar radiation gets converted into DC electricity directly. This
electricity can either be used as it is or can be stored in the battery. This stored electrical
energy then can be used at night. SPV can be used for a number of applications such as:
a. Domestic lighting
b. Street lighting
c. Village electrification
d. Water pumping
e. Desalination of salty water
f. Powering of remote telecommunication repeater stations and
g. Railway signals.
If the means to make efficient use of solar energy could be found, it would reduce our
dependence on non-renewable sources of energy and make our environment cleaner.
1.2 Project Definition
When you have a solar power cell phone battery, you can use the sun’s free energy to
have your battery charged without any cost to you. An added benefit is that you can charge
that battery, no matter where you are, as long as the sun is out. One of the best aspects of a
solar power cell phone battery is that it can be charged with a portable solar power charger.
This means that you won’t have to worry about your phone dying on you in the middle of an
important business call because it can be charged wherever you go. It utilizes a natural
resource to save you money and keep your cell phone charged and ready to use.
Imagine if you were hiking in the mountains and got lost and your cell phone battery
died. Well that wouldn’t be a problem with a solar power cell phone battery. Simply charge it
with a solar charger and you’re saved!
Extend the life of your cell phone with a solar power cell phone battery.
The proposed system have a solar panel and a electronic circuitry to maintain required
current & voltage to charge mobile phone battery. Size of solar panel is an important concern
2.1.1 Parts of the System
Charge controller circuitry
Rechargeable battery system
Solar Energy is the energy received from the sun that sustains life on earth. For many
decades solar energy has been considered as a huge source of energy and also an economical
source of energy because it is freely available. However, it is only now after years of research
that technology has made it possible to harness solar energy.
Some of the modern Solar Energy systems consist of magnifying glasses along with
pipes filled with fluid. These systems consist of frontal glass that focuses the sun’s light onto
the pipes. The fluid present in the pipes heats up instantly. In addition they pipes are painted
black on the outside so as to absorb maximum amount of heat. The pipes have reflective
silver surface on the back that reflects the sunlight back, thus heating the pipes further. This
reflective silver surface also helps in protecting everything that is on the back of the solar
In this project, our primary concern will be on solar energy. Solar panel will convert
solar energy into electrical energy. This electrical energy will controlled by the electronic
circuitry, so that required amount of voltage & current we can utilized to charge mobile
3.3 Basic of Solar Energy
India gets more than 5,000 trillion kWh of Solar Energy every year. This much of
energy is very high compared to the overall energy requirement and consumption in the
country. As regards the latest trends in developed countries like the U.S. and Japan, it is
estimated by industry experts that millions of homes around the world are going to switch to
solar energy in the next few years.
Solar Energy is already being successfully used in residential and industrial settings
for cooking, heating, cooling, lighting, space technology, and for communications among
other uses. In fact, fossil fuels are also one form of solar energy stored in organic matter.
With fossil fuels making major impact on the environment and raising issues of pollution and
global warming, solar energy has increased in its importance to industries and homes. While
the reserves of fossil fuels are restricted, there is no limitation to the availability of solar