Renewable Energy is a term that refers to energy sources that are
renewable in nature, meaning that more and more is continuously
generated, and for all practical purposes, that are virtually limitless
in supply. Energy from our sun is one such example. Technically,
the sunlight will fade in about 5 billion years, but for all practical
purposes and human timescales, we will consider this a continuous
and infinite resource. The sun isn't going to burn out any time
Other renewable energy sources include wind and geothermal power.
Wind power is generated by placing large windmills in windy
areas, usually at high altitude to be maximally effective. Wind
power, like solar power, is clean, but is also plagued by cost of setup
and cost per kilowatt. Wind power may be unreliable in certain areas
where the wind isn't strong year-round.
Geothermal energy, a form of energy generated from the tectonic
pressures and movements that heat the earth's crust, is used to boil
steam and generate electricity.
Non-renewable energy is energy that is generated from
non-renewable material reserves.
These non-renewable resources are limited in supply that is to
say that to be non-renewable a resource has to have a reasonably
finite amount available for economically feasible extraction.
We usually consider a resource non-renewable if it will non
regenerate rapidly enough to meet our needs.
Oil and coal are examples of non-renewable energy.
Like all other fossil fuels, these non-renewable energy sources
are created deep within the Earth, and cannot be replaced rapidly
enough to meet the needs of any advanced civilization. Effectively,
once we run out, we run out.
We'll see miniscule amounts of oil and coal deposits build up, but it
won't be for millions of years, eons of time, before our reserves are
Nonrenewable sources of energy are used once, and afterwards
are gone forever
Benefits and advantages of solar energy
Solar energy is a renewable and inexhaustible source of powerful
energy that is derived from the sun. According to astronomers,
the sun will continue to shine for quite a number of million of years
and therefore, you shall have access to unlimited and free
source of power for a very long time, without having to worry
about the depleting natural energy resources.
There is no fear of causing any kind of environmental damage or
environmental pollution with solar power generation. This kind
of energy production does not destroy the ozone layer. Solar
energy is regarded as environment friendly, clean and safe.
Solar energy is a renewable resource, The solar energy supply
will last as long as the sun.
By switching over to solar energy, you can help to save your
planet and further the cause of the wellbeing of the earth.
Solar Energy Advantages
I. Saves you money
a. After the initial investment has been recovered, the energy from the
sun is practically FREE.
b. Solar energy does not require any fuel. It's not affected by the supply
and demand of fuel and is therefore not subjected to the ever-increasing
price of gasoline.
c. The savings are immediate and for many years to come.
d. The use of solar energy indirectly reduces health costs.
II. Environmentally friendly
a. Solar Energy is clean, renewable (unlike gas, oil and coal) and
sustainable, helping to protect our environment
b. It does not pollute our air by releasing carbon dioxide, nitrogen oxide,
sulphur dioxide or mercury into the atmosphere like many traditional
forms of electrical generations does
c. Therefore Solar Energy does not contribute to global warming, acid
rain or smog.
d. By not using any fuel, Solar Energy does not contribute to the cost
and problems of the recovery and transportation of fuel or
the storage of radioactive waste
III. Independent/ semi-independent
a. A Solar Energy system can operate entirely independent, not requiring a
connection to a power or gas grid at all. Systems can therefore
be installed in remote locations (like holiday log cabins), making it
more practical and cost-effective than the supply of utility electricity to
a new site.
IV. Low/ no maintenance
a. Solar Energy systems are virtually maintenance free and will last for
b. Once installed, there are no recurring costs
c. They operate silently, have no moving parts, do not release offensive
smells and do not require you to add any fuel
Solar Energy Disadvantages
a. The initial cost is the main disadvantage of installing a solar
energy system, largely because of the high cost of the semi-
conducting materials used in building one.
b. Solar panels require quite a large area for installation to achieve
a good level of efficiency.
c. The efficiency of the system also relies on the location of the
sun, although this problem can be overcome with the
installation of certain components.
d. The production of solar energy is influenced by the presence of
clouds or pollution in the air
e. Similarly, no solar energy will be produced during nighttime
although a battery backup system and/or net metering will solve
this problem for knowing more, as concern NET METERING follow link:www.dsireusa.org
Usage of concave mirrors
Using concave mirrors for producing thermal energy, in order to save
money by reducing energy costs by a considerable amount.
Taking into consideration that boiling -- water is needed for
many reasons in our everyday life,.
Concave mirror can be used to heat water using solar energy.
The point F is the focus of the mirror. This is the point at
which the rays o f light parallel to the axis converge after being
The point C is the centre of curvature of
HEATING WATER SYSTEM
At the focus of CM,
the temperature is
Platform must be movable-
to move the CM and follow
the sun movement ( rays of
light parallel to the axis ) for
UTILITY AND USE OF SOLAR ENERGY
Heating water and producing electric energy through solar cells.
There are two main forms of solar cells/panels (photovoltaic cells)
in existence today, and these are;
"solar electricity panels““
"solar hot water panels".
The two different technologies allow us to either generate
electricity for our homes or to heat the water we use.
PRODUCING ELECTRIC ENERGY THROUGH SOLAR PANELS
SOLAR PANELS-- (arrays of photovoltaic cells )
What is a solar electricity panel?
A solar panel ( also known as a photovoltaic panel or photovoltaic
module ) is a device that converts photons of light from the Sun and
converts them into an electric current.
Solar Panels are a form of active solar power, a term that describes how
solar panels make use of the sun's energy: solar panels harvest sunlight
and actively convert it to electricity. Solar Cells, or photovoltaic cells, are
arranged in a grid-like pattern on the surface of the solar panel. These
solar voltaic cells collect sunlight during the daylight hours and covert it
The heart of any solar power system is the solar panels,
Solar panels (arrays of photovoltaic cells) make use of renewable energy
from the sun,
It is vital to install your solar
panel so that it gets the most
direct sun exposure - you want
to make sure your solar panel
is maximally effective year
To do this, there are several web-based solar resources to help you
properly set up and install your solar panels by tracking the
position of the sun in the sky over the course of the year.
Solar Panel Installation Tips
12 volt 60 watt solar panel measure about 20 X 44 inches (5Amps)
Solar Panels --- are typically installed on rooftops, building tops, or
Position your solar panel in direct sunlight
Solar Panels perform at optimum capacity when placed in direct
sunlight. Try to position your photovoltaic array directly under the
noontime sun for maximum efficiency from your photovoltaic unit.
Notice obstructions to sunlight
Remove all items unnecessary items or trim branches that may be
blocking sunlight to your solar unit. Trace the path of the sun in the sky
to determine if an object is casting a shadow over your solar
If this is the case, then the operating efficiency of your unit will
Mounting your Solar Panel
Solar Panel Mounts are used to install photovoltaic solar panels. Solar
panel mounts come in three main varieties: pole mounts, roof-ground
mounts, and flush mounts. Using these mounts, you can install your
solar panel against the side of a pole, on your roof, or even install them
as a free-standing unit.
A SOLLAR CELL ( A PHOTOVOLTATIC CELL )-
-Is an electrical component that converts light into electrical
The physical principle behind this is the photovoltaic effect.
Several solar cells can be electrically connected to form a solar
The type of connection that is selected allows the electrical
operating range (power and voltage) to be specifically
tailored to the respective application of the solar panel.
Solar cells are made of various semiconductor materials.
Semiconductors are substances that can conduct electricity
when heat or light is added, and they also act as electrical
insulation at low temperatures
How do Photovoltaics Work?
Photovoltaics is the direct conversion
of light into electricity at the atomic
Some materials exhibit a property
known as the photoelectric effect
that causes them to absorb photons
of light and release electrons.
When these free electrons are
captured, an electric current results
that can be used as electricity.
A solar cell ( A PHOTOVOLTATIC CELL )
(arrays of photovoltaic cells )
Sunlight is composed of photons containing energy.
When photons strike a PV cell, their energy is transferred to
an electron in the semiconductor material of the cell.
With this extra energy, the electron is then able to escape from
its normal position in the atom creating a "hole", which will
become part of a current in an electrical circuit.
A so-called p-n-junction is created on the barrier layer.
The special feature of this barrier layer is that a strong
electrical field is created locally.
If light falls onto the semiconductor free positive and negative
charge carriers are created due to the photoelectrical
If this process takes place close to the p-n-junction, the local
electrical field ensures that the positive and negative charge
carriers are separated from each other.
These move toward the outer electrodes ( contact fingers
or reverse side contact ) and generate current; the solar
cell therefore works similar to a battery.
If the electrodes are then connected to an electrical consumer,
A diode ( semi - conductor ) is formed when two layers of
semiconductor materials are doped so that one will
conduct negative carriers and the other positive carriers.
When photons fall on these layers they transfer energy and
momentum to charge carriers, which increase their potential
energy by an amount depending on the diode's material
properties. Because of their electrical properties,
+ + + + + + + + + + + + +
Solar cell -- construction
PV modules produce direct current ( DC ) rather than
alternating current ( AC ). In the simplest PV systems, DC
current is used immediately in applications but where AC is
required, an ,inverter is added to the system to convert DC
Multiple solar panels are wired together to produce
the: voltage, and, amperage, -- needed
DC system with batteries
12V - DC
12V - DC
DC to AC inverter
Solar system containing DC to AC invetror
Utility-interactive system without batteries
Solar PV array
Grid Tie Inverter
AC Utility Meter
A charge controller monitors the battery's state-of-charge
to insure that when the battery needs charge-current it gets it,
and also insures the battery isn't over-charged.
Connecting a solar panel to a battery without a regulator
seriously risks damaging the battery and potentially causing a
Charge controllers (or often called charge regulator) are rated
based on the amount of amperage they can process from
a solar array.
If a controller is rated at 20 amps it means that you can connect
up to 20 amps of solar panel output current to this one
The Deep Cycle batteries used are designed to be discharged
and then re-charged hundreds or thousands of times.
An inverter is a device which changes DC power stored in a batteryAn inverter is a device which changes DC power stored in a battery
to standardto standard 120/240120/240 VAC electricity (also referred to asVAC electricity (also referred to as
Most solar power systems generate DC current which is stored inMost solar power systems generate DC current which is stored in
Nearly allNearly all lightinglighting,, appliancesappliances,, motorsmotors, etc., are designed to use, etc., are designed to use
ac power, so it takes an inverter to make the switch from battery-ac power, so it takes an inverter to make the switch from battery-
stored DC to standard power (120 VAC, 60 Hz).stored DC to standard power (120 VAC, 60 Hz).
In an inverter, direct current (DC) is switched back and forth toIn an inverter, direct current (DC) is switched back and forth to
produce alternating current (AC). Then it is transformed, filtered,produce alternating current (AC). Then it is transformed, filtered,
stepped, etc . To get it to an acceptable output waveform.stepped, etc . To get it to an acceptable output waveform.
PV MODULES IN SERIES AND PARALLEL
Photovoltaic modules and batteries are a system’s building
While each module or battery has a rated voltage or
They can as well be wired together to obtain a desired system
voltage and amperage.
When voltage sources are connected in series the voltage
Series wiring does not increase the amperage produced.
Rules concerning series circuits:
When loads or sources are wired in series-voltages are
o Current is equal through all parts of the circuit.
o In a series circuit batteries are connected end -to-end
or positive ( + ) to negative ( - ).
o Batteries placed in series will provide a total voltage equal
to the sum of each individual battery voltage.
PV MODULES IN SERIES
When two 12V DC,
3Amps modules are
wired in series
What is the resulting
system voltage and
V-DC= 12V+12V = 24V
When loads or sources are wired in parallel, currents are additive
and voltage is equal through all parts of circuit.
To increase the amperage of a system the voltage sources must
be wired in parallel
Parallel wiring is from positive ( + ) to positive ( + ) and negative
( - ) to negative ( - )
Batteries are as well often connected in parallel to increase
the total Amps, which increase the storage capacity and prolongs
the operating time.
3A 12 Volts
at 6 Amps
PV Modules in parallel
this figure shows PV
modules wired in
parallel to get
NOTICE that parallel
wiring increases the
current produced and
does not increase
PV MODULES IN SERIES AND PARALLEL
Systems may use a mix of series and parallel wiring to
obtain required voltages and amperages
at 6 Amps
How much would a solar system cost?
What does count is:
Where you are in the world.
How much sun you get per day.
How much you use
Where you are affects how much yearly average sun you get. Solar
panels make power from the sun, so no sun, no power.
In the US that can vary from a yearly average of about 4 to 6 hours per
day. You will usually get more in summer, less in winter.
How much sun you get also depends on where the panels are, how
much - if any – shade they might get during the day, and what angle
and direction you can mount them at.
To work best, solar panels should be aimed South,
Factors of Solar Cell Costs
Solar panels of the same size may produce variable amounts of
electricity - this discrepancy arises from variations in the functioning
age of the solar cells, the quality of the solar cells, and with what
technology they were produced. Early solar cells, for example, are not
quite as efficient as modern solar cells,
As another example, two identical solar cells are purchased. One is left
in storage and the other has been in use for three years. Solar
panels have an effective lifespan of about 20 to 25 years, and their
value and wattage output decrease steadily over time.
The solar cell that has been in storage will be more valuable than
one that has been actively converting sunlight to electricity for a long
In summary, although two solar panels may seem identical, there are
a number of other factors you need to take into consideration.
Quality, age, and technology all play a role in the cost of the
How to figure the cost for 100% solar power
First, take number of KWH shown on your bill. Divide that by 30.
That gives you your average daily usage. So if you use 700 KWH,
that is 23.3 KWH per day.
Take that number. Divide it by the number of full sun hours you get
per day on a yearly average. Multiply it by 1.15.
That will give you a pretty close estimate of how many watts of solar
panel you need.
So if you get 5 hours per day, divide 23.3 by 5 - that gives you 4.66
KW, or 4,666 watts.
Multiply that by 1.15, which gives you 5,360 watts of solar panel
Average installed cost of solar electric if you do it yourself is around
$7 per watt.
So that system will cost you around $37,500.
A short introduction to: Solar Hot Water Panels
The use of solar panels to heat
water is becoming increasingly
popular around the world due to
the energy and money saving
associated with this method.
Solar energy panels can use the
sun’s energy to heat water for
sanitary use at home or for pools
and hot tubs.
Now imagine if you could combine not only a solar panel hot
water heating system, but also an average solar electricity
system. This would save a heap on energy and electricity
The combination of a solar hot water panel with other
renewable energy technologies, such as solar panels, or a
home wind turbine can work quite well together in providing a
source of cheap, clean, and renewable energy for our homes.
.A good solar hot water panel system
is able to provide an average
household with around a third of its
annual hot water supply. While this may not
sound much, it can reduce energy costs by a