ÿ To Convert Solar Energy to Electrical Energy
1. Solar Panel ( 5.0 V)
2. IC7805 (Voltage regulator)
3. 100?F Capacitor
4. 20 ?F Capacitor
5. 100nF Capacitor
6. U.S.B Cable
7. PCB Board
8. Shouldering Kit
Solar energy is radiant light and heat from the Sun that is harnessed using a range of ever-
evolving technologies such as solar heating, photovoltaics, solar thermal energy, solar
architecture and artificial photosynthesis.
It is an important source of renewable energy and its technologies are broadly characterized as
either passive solar or active solardepending on how they capture and distribute solar energy or
convert it into solar power. Active solar techniques include the use of photovoltaic
systems, concentrated solar power and solar water heating to harness the energy. Passive solar
techniques include orienting a building to the Sun, selecting materials with favorable thermal
mass or light-dispersing properties, and designing spaces that naturally circulate air.
The Earth receives 174,000 terawatts (TW) of incoming solar radiation (insolation) at the
upper atmosphere. Approximately 30% is reflected back to space while the rest is absorbed by
clouds, oceans and land masses. The spectrum of solar light at the Earth's surface is mostly
spread across the visible and near-infrared ranges with a small part in the near-ultraviolet. Most of
the world's population live in areas with insolation levels of 150-300 watts/m², or 3.5-7.0 kWh/m²
Solar radiation is absorbed by the Earth's land surface, oceans – which cover about 71% of the
globe – and atmosphere. Warm air containing evaporated water from the oceans rises,
causing atmospheric circulation or convection. When the air reaches a high altitude, where the
temperature is low, water vapor condenses into clouds, which rain onto the Earth's surface,
completing the water cycle. The latent heat of water condensation amplifies convection, producing
atmospheric phenomena such as wind, cyclones and anti-cyclones. Sunlight absorbed by the
oceans and land masses keeps the surface at an average temperature of
14 °C. By photosynthesis, green plants convert solar energy into chemically stored energy, which
produces food, wood and the biomass from which fossil fuels are derived.
The total solar energy absorbed by Earth's atmosphere, oceans and land masses is approximately
3,850,000 exajoules (EJ) per year. In 2002, this was more energy in one hour than the world used
in one year. Photosynthesis captures approximately 3,000 EJ per year in biomass. The amount of
solar energy reaching the surface of the planet is so vast that in one year it is about twice as much
as will ever be obtained from all of the Earth's non-renewable resources of coal, oil, natural gas,
and mined uranium combined
The potential solar energy that could be used by humans differs from the amount of solar energy
present near the surface of the planet because factors such as geography, time variation, cloud
cover, and the land available to humans limit the amount of solar energy that we can acquire.
Geography affects solar energy potential because areas that are closer to the equator have a
greater amount of solar radiation. However, the use of photovoltaic that can follow the position of
the sun can significantly increase the solar energy potential in areas that are farther from the
equator. Time variation effects the potential of solar energy because during the nighttime there is
little solar radiation on the surface of the Earth for solar panels to absorb. This limits the amount of
energy that solar panels can absorb in one day. Cloud cover can affect the potential of solar
panels because clouds block incoming light from the sun and reduce the light available for solar
In addition, land availability has a large effect on the available solar energy because solar panels
can only be set up on land that is otherwise unused and suitable for solar panels. Roofs have
been found to be a suitable place for solar cells, as many people have discovered that they can
collect energy directly from their homes this way. Other areas that are suitable for solar cells are
lands that are not being used for businesses where solar plants can be established.
Solar technologies are characterized as either passive or active depending on the way they
capture, convert and distribute sunlight and enable solar energy to be harnessed at different levels
around the world, mostly depending on distance from the equator. Although solar energy refers
primarily to the use of solar radiation for practical ends, all renewable energies, other
than geothermal power and Tidal power, derive their energy either directly or indirectly from the
Active solar techniques use photovoltaic, concentrated solar power, solar thermal collectors,
pumps, and fans to convert sunlight into useful outputs. Passive solar techniques include selecting
materials with favorable thermal properties, designing spaces that naturally circulate air, and
referencing the position of a building to the Sun. Active solar technologies increase the supply of
energy and are considered supply side technologies, while passive solar technologies reduce the
need for alternate resources and are generally considered demand side technologies.
∑ Solar panel
Solar panel refers to a panel designed to absorb the sun's rays as a source of energy for
generating electricity or heating.
A photovoltaic (PV) module is a packaged connect assembly of typically 6×10 solar cells. Solar
Photovoltaic panels constitute the solar array of a photovoltaic system that generates and
supplies solar electricity in commercial and residential applications. Each module is rated by
its DC output power under standard test conditions, and typically ranges from 100 to 365 watts.
The efficiency of a module determines the area of a module given the same rated output – an 8%
efficient 230 watt module will have twice the area of a 16% efficient 230 watt module. There are a
few commercially available solar panels available that exceed 22% efficiency and reportedly also
exceeding 24%. A single solar module can produce only a limited amount of power; most
installations contain multiple modules. A photovoltaic system typically includes a panel or an array
of solar modules, a solar inverter, and sometimes a battery and/or solar tracker and
∑ IC 7805 voltage Regulator
IC 7805 is a 5V Voltage Regulator that restricts the voltage output to 5V and draws 5V regulated
power supply. It comes with provision to add heat sink.
The maximum value for input to the voltage regulator is 35V. It can provide a constant steady
voltage flow of 5V for higher voltage input till the threshold limit of 35V. If the voltage is near to
7.5V then it does not produce any heat and hence no need for heat sink. If the voltage input is
more, then excess electricity is liberated as heat from 7805.
It regulates a steady output of 5V if the input voltage is in rage of 7.2V to 35V. Hence to avoid
power loss try to maintain the input to 7.2V. In some circuitry voltage fluctuation is fatal (for e.g.
Microcontroller), for such situation to ensure constant voltage IC 7805 Voltage Regulator is used.
For more information on specifications of 7805 Voltage Regulator please refer the data sheet here
(IC 7805 Voltage Regulator Data Sheet)
First of all, take the solar panel. On its back side, we can see two connecting wires. One is in red
colour and the other is in black. The red wire is the positive terminal and the black wire is the
negative terminal. There is nothing much to do with the solar panel.
Solder all the components on a PCB as shown in the circuit diagram. To test the regulator circuit,
connect voltage between 8 V and 18V to the input of voltage regulator. Now, measure the output.
The output should be constant and it can be any value between 4.75 V and 5.25V. If so, your
circuit is working properly.
Next, we need to connect it to the USB port.
Solder the positive output wire of the voltage regulator to the USB's positive. Similarly, connect the
negative output of regulator to the negative of USB. The USB port must be fixed properly to the
PCB. Next, connect the solar panel to the input of the voltage regulator (positive of solar panel to
positive input of voltage regulator and negative of solar panel to negative input). Once everything
is connected, measure the output voltage in open sun light. It should be around 5V. Now, connect
your mobile phone and you will see it charging.
1. Relatively small size allows mobile use.
2. System requires no electrical start up power.
3. Ability to recharge AA battery anytime and anywhere there is sunlight.
4. Low maintenance, emission free and environmentally friendly power source.
1. To make sure we have plenty amount of energy in future, it’s up to all of us to use energy
2. We must all conserve energy and use it efficiently.
3. All energy sources have an impact on environment concerns about the green house effect
and global warming To make sure we have plenty amount of energy in future, it’s up to all of
us to use energy wisely.
4. We must all conserve energy and use it efficiently.
5. All energy sources have an impact on environment concerns about the green house effect
and global warming.
6. In solar charger ripples will not be there as we use DC power directly to charge the mobile.
7. Battery life increase as we use solar mobile charger.
8. Adaptability is high.