• The Sun delivers 17,000 million MW
of energy to the earth each year.
• Solar architecture dates back to
2500 BCE and was used by many
• The fossil fuels are non renewable
sources so we can not depend on
• Though nuclear energy is a clean
and green energy ,as said by
Dr.A.P.J Abdul Kalam, there are
always some problems associated
• So the only option we have is solar
energy because it is a nonpolluting
and silent source of electricity and
also low maintainance and long
So why don‟t we use it?
You need storage for solar power for power at night.
There is a net metering system that allows the utility companies to "absorb"
the energy your system would generate, and then credit you for the energy
you need supplied. Consumption of energy is supplied from the power grid at
any time during the day or night. First the credits are used up, and you pay
only for the excess usage.
Electricity from solar power is expensive.
Nothing is cheap in these days. It‟s still found to be less expensive to
install a solar system than connect to the grid if you are more than about
500 yards from a utility connection
Solar power isn‟t entirely developed.
No technology is ever „finished.‟ Solar energy generation is a fairly mature
technology at present, but research and development continues, of course.
So why don‟t we use it?
Solar-powered life requires sacrificing modern conveniences.Solar-powered
homes have all the appliances that other homes have. Eg: washers, dryers,
computers, television sets, refrigerators , etc.
Why Don't We Use More
• Renewable Energy Technologies Are CapitalIntensive.
• generally more expensive to build and to operate
than coal and natural gas plants.
• Renewable Resources Are Often Geographically
• building transmission lines to deliver power to
large metropolitan areas is expensive.
Solar Energy Can Be Used for
Both Heat and Electricity.
Heats water for
homes, pools, and
Heats spaces such as
PV devices or “solar
cells” change sunlight
Can be applied in three ways:
Commonly called Solar
Home Systems (SHS)
A system not connected
to the grid.
Homes are connected to
the grid for if there is
ever a need.
Used for areas with
How do solar panels work?
-Sunlight hits the solar panels(also know as photovoltaic/
PV) and are absorbed by semi-conducting materials
such as silicone.
-Electrons are knocked loose from their atoms, which
allow them to flow through the material to produce
electricity.Also called the photovoltaic (PV) effect.
-An array of solar panels converts solar energy into DC
(direct current) electricity.
-The DC electricity then enters an inverter.
-The inverter turns DC electricity into 120-volt AC
(Alternating Current)electricity needed by home
-The AC power enters the utility panel in the house.
-The electricity is then distributed to appliances or
lights in the house.
-When more solar energy is generated that what
you're using - it can be stored in a battery as DC
electricity. The battery will continue to supply your
home with electricity in the event of a power
blackout or at nighttime.
-When the battery is full the excess electricity can be
exported back into the utility grid, if your system is
connected to it.
-Utility supplied electricity can also be drawn form the
grid when not enough solar energy is produced and
no excess energy is stored in the battery, i.e. at
night or on cloudy days.
-Any surplus energy is sold back to the utility company.
Facts about Solar Energy Usage:
• Solar Energy is measured in kilowatt-hour. 1
kilowatt = 1000 watts.
• 1 kilowatt-hour (kWh) = the amount of electricity
required to burn a 100 watt light bulb for 10
• According to the US Department of Energy, an
average American household used approximately
866-kilowatt hours per month in 1999 costing
• About 30% of our total energy consumption is
used to heat water.
Just how much does solar energy cost to
It varies on:
Size of your household.
Amount of electricity you use.
How much sun your area receives.
Available Government funding.
Facts about Solar Energy Systems:
• A home solar system is typically made up of solar panels,
an inverter, a battery, a charge controller, wiring and
• A 1-kilowatt home solar system consists of about 10-12
solar panels and requires about 100 square feet of
• A 1 kilowatt home solar system will generate
approximately 1,600 kilowatt hours per year in a sunny
climate (receiving 5.5 hours of sunshine per day) and
approximately 750 kilowatt hours per year in a cloudy
climate (receiving 2.5 hours of sunshine per day).
• A 1-kilowatt home solar system will prevent
approximately 170 lbs. of coal from being burned, 300
lbs of CO2 from being released into the atmosphere and
105 gallons of water from being consumed each month!
Pros and Cons of Solar Energy
• Low to no
• Saves you money in
the long run.
• High installation costs.
• The production of
solar energy is
influenced by the
presence of clouds or
pollution in the air.
• Solar panels require
quite a large area for
installation to achieve
a good level of