Wind energy is a renewable energy source that is growing rapidly due to declining costs. Modern wind turbines convert the kinetic energy of wind into electrical energy. Large wind farms produce bulk power for the electrical grid, while small turbines can power homes and other buildings off-grid. Wind energy has advantages of being renewable and reducing emissions, but is limited by intermittent wind resources. Future applications may include turbines incorporated into skyscraper designs to generate power.

1. BUILDING TECHNOLOGY II
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2. Alternative energy is a term used for some energy
source that is an alternative to using fossil fuels.
Generally, it indicates energies that are non-
traditional and have low environmental impact.
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3. 3
The current global trend of depleting energy resources
(especially fossil fuel) forces man to search for alternative
& renewable form of energy in order to :
a. Overcome the rising cost of fuel which increases
the prices of food, heating, electricity & transportation.
b. Reduce the emission of greenhouse gases which
damages the environment and endangers the earth eco-
system.
c. Secure the normal function & activities of human
civilization by means of reliable energy sources.

4. 4
Types of energy which may be incorporated in
building design or
connected to the electrical grid:
1. Wind Energy
2. Solar Energy
3. Hydro energy
4. Geothermal energy
5. Tidal energy
6. Wave energy
7. Biofuel energy
8. Biomass energy
9. Hydrogen energy
(Note: Nuclear energy is not a renewable
form of energy )

5. □ The origin of wind is complex. The Earth is unevenly heated by the
sun resulting in the poles receiving less energy from the sun than
the equator does.
□ The dry land heats up (and cools down) more quickly than the
seas do. The differential heating drives a global atmospheric
convection system reaching from the Earth's surface to the
stratosphere which acts as a virtual ceiling.
□ Most of the energy stored in these wind movements can be found
at high altitudes where continuous wind speeds of over 160 km/h
(100 mph) occur.
□ Wind energy is much greater in the ocean than on land due to
topography.
□ There is an estimated 72 TW of wind energy on the Earth that
potentially can be commercially viable.
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What is Wind Energy .

6. 1.1Historical Use of Wind Energy.
□ As early as 5000 BC, wind energy
was harnessed to propel boats along
the Nile River.
□ Early in the 20th century, windmills
were used in the Great Plains of
America to pump water & generate
electricity.
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7. 1.1 Historical Use of Wind Energy.
□ The Dutch were responsible for
refining the windmill.
□ As early as 1390, they had connected
the mill to "a multi-story tower, with
separate floors devoted to grinding
grain, removing chaff, storing grain,
and (on the bottom) living quarters.
□ The first large windmill to produce
electricity was built in 1888 in America
which produced 12 kW and later replaced
by 70-100 kW modern wind turbines.
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8. □ Modern wind turbine takes advantage of Wind
energy which is caused by :
- the uneven heating of the atmosphere by the
sun.
- the irregularities of the earth‘s surface.
- rotation of the earth.
□ Wind power is the process of converting
‘kinetic energy’ of the wind into mechanical
energy of turbine to generate electricity.
New designs for adjustable blades on wind towers
now allow wind farms to be sited in areas that
lack steady winds.
wind turbines that generate the electricity from
strengthened fiber blades can produce more
electricity than in the past
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1.2 Modern Wind Turbine.

9. 1.3 How Wind Turbine Works ?
□ Wind turbine works the opposite of
a fan – instead of using electricity to
make wind, wind turbines use wind
to make electricity.
□ The wind turns the blades which
spins a shaft connected to a
generator.
□ Larger turbines are grouped
together in wind farms, which
provide bulk power to the
electrical grid.
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10. 1.4 Size of Wind Turbine .
□ Utility-scale turbines range in size from 100 kW
to as large as several megawatts and
connected to the electrical grid.
□ Single small turbines, below 100 kW
are used for homes, telecommunication
dishes, or water pumping.
□ Small turbines are sometimes used in
connection with diesel generators,
batteries, and photovoltaic systems.
These systems are called hybrid wind
systems and are typically used in remote,
off-grid locations, where a connection to
the utility grid is not available.
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11. □ Wind energy is fueled by the wind, a
renewable form of energy.
□ Wind energy doesn't pollute the air
like power plants that rely on
combustion of fossil fuels, such as
coal or natural gas.
□ Wind turbines don't produce
atmospheric emissions that cause
acid rain or greenhouse gasses.
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1.5 Advantages of Wind Turbine .

12. □ Wind energy is one of the lowest-
priced renewable energy
technologies available today,
costing between 4 and 6 cents per
kilowatt-hour.
□ Wind power can be generated in
remote areas, including out in the
oceans.
□ Wind turbines can be built on farms
or ranches, where the land can still
be used for farming.
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1.5 Advantages of Wind Turbine .

13. □ Even though the cost of wind power has
decreased dramatically in the past 10 years, the
technology requires a higher initial investment
than fossil-fueled generators.
□ Wind energy cannot be stored (unless batteries
are used) . As the winds is intermittant ,
□ the wind to drive the turbines may be
intermittent and that it does not always blow
when electricity is needed it is difficult to be
harnessed to meet the timing of electricity
demands.
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1.6 Disadvantages of Wind Turbine .

14. 1.6 DISADVANTAGES OF WIND TURBINE .
□ Good wind sites are often located
in remote locations, far from cities
where the electricity is needed.
□ It forms a danger threat to birds
and paragliders.
□ Offshore wind farms add 80–110
dB to the existing low-frequency
ambient noise which could harm
sea mammals & restricts their
communication.
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15. □ Wind power is now the world's
fastest growing energy source and
has also become one of the most
rapidly expanding industries.
□ It can serve as an alternative to fossil
fuel-generated electricity.
□ In 1997, wind power generated only
7,636 megawatts of power, but this
figure had risen to 47,912 megawatts
by the end of 2004, a more than six
fold increase.
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1.7 Future of Wind Energy.

16. 1.7 Future of Wind Energy.
□ As of 1999, global wind energy
capacity topped 10,000 megawatts,
which is approximately 16 billion
kilowatt-hours of electricity – enough to
serve over 5 cities the size of Miami.
□ 3 billion kWh of electricity produced
by America's wind machines annually
displace the energy equivalent of 6.4
million barrels of oil and avoid 1.67
million tons of carbon emissions, as well
as sulfur and nitrogen oxide emissions
that cause smog and acid rain.
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17. □ Its cost has reduced more than 80% since
1980s. At 2 to 3 cents premium per kWh and
compare this to 4.8 to 5.5 cents per kWh
for coal or 11.1 to 14.5 cents per kWh for
nuclear power, wind energy is therefore
"cheaper than any other new electric
generation except natural gas.
□ There will be the next major step for this
technology and will result in a dramatic
increase in decentralized electricity
generation.
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1.7 Future of Wind Energy.

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1.8 Future Architecture Wind Energy.
Twisting Skyscraper- Dubai.
□ Each of the 59 floors is rotating unevenly
around a central concrete core.
□ Wind turbines are stacked horizontally
between each floor, so that when exposed
to the atmosphere 50 or 100 or 500 feet
off the ground, the wind turns the
turbines, generating electricity for the
buildings’ use—and more.
□ Combined with solar panels, the wind
turbines could produce about $7 million
of surplus electricity per year, making the
design a potentially profitable long-term
investment.

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□ Each turbine generates 0.3 megawatts of
electricity, so that the building’s 50 total
turbines can generate 1,200,000 kilowatt-
hours of energy per year.
□ As an average family’s annual power
consumption is about 24,000 kilowatt-
hours, each turbine can supply energy for
about 50 families.
□ The tower will have 200 apartments, which
will use just four of the turbines for their
energy needs. Another four of the
remaining 44 turbines would provide power
to the neighborhood of the building, and
there would still be 40 extra turbines, which
could supply power for 5-10 more buildings.

20. □ It was first used in212 BC by Greek genius
Archimedes to defend the harbour of
Syracuse against the Roman fleet.
□ 1860-1881. August Mouchout was the first
man to patent a design which turned solar
energy into mechanical steam power to
operate steam engine. He later connected it
to refrigeration device to illustrate that the
sun’s rays can be used to make ice.
□ 1860-1881. William Adams developed the
use of mirrors to power steam engine called
the Power Tower, a concept still in use today.
□ 1883. Charles Fritz converted the sun’s rays
into electricity by using solar cell.
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2.1 History of Solar Energy.

21. Advantage of Solar Energy:
 Solar energy makes use of a renewable natural resource that is
readily available in many parts of the world.
 It is emission-free.
 Technological advances have reduced costs to a point that it can
compete with fossil fuel alternatives in specific circumstances.
 The technology is scalable in that it can be used for domestic
heating purposes or on a larger scale for commercial electricity
generation.
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22. Disadvantages of Solar Energy:
 thermal systems do not work at night or
in inclement weather.
 The cost
 the amount of land required for large-
scale electricity production
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2.2 Modern Solar Energy Application ( Large Scale).
- Power Tower.
□ Solar One was completed in 1981 to
produce 10MW of electricity.
□ It uses 1818 mirrors which track the sun ,
each 40m2 covering a total area of 126
acres.
□ It collects the sun’s energy by
concentrating the sun’s rays onto a
common focal point on the tower where a
black receiver absorbs the heat.
□ High temperature ‘heat transfer fluid’ is
used to carry the energy to a boiler on the
ground .
□ Steam produced by the boiler is used to
spin a series of turbines which generate
electricity.
California Solar One Power Station.

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2.3 Modern Solar Energy Application ( Large Scale).
- Parabolic Trough.
□ Completed in 2007, it is the third largest solar
power plant in the world.
□ It uses 760 parabolic troughs(using more
than 180,000 mirrors) to generate 64MW ,
enough power for more than 14,000 households.
□ The mirrors (usually alligned on north-south
axis ) are fitted with motor to track the sun’s
position and concentrate the sun's rays) onto
specially coated glass tubes .
□ Heat transfer fluid (usually oil) which runs
through the tube absorbs the concentrated
sunlight and is then used to heat steam in a
standard turbine generator.
Nevada Solar One Power Station.

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2.4 Modern Solar Energy Application ( Small Scale).
- Photovoltaic Panel.
□ Photovoltaic systems, or “PV,” work by
converting sunlight into electric energy.
□ Each PV panel is composed of a group of solar
(photovoltaic) cells made of a semiconductive
material, often crystalline silicon, which absorbs
light efficiently.
□ A photovoltaic cell is a sandwich of two
semiconductor materials. It is created by placing
a top layer of negatively charged N-type silicon
against a bottom layer of positively charged P-
type silicon – this forms a diode which is
connected in a circuit via metal conductors on
the top & bottom of the silicon sandwich.

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2.4 Modern Solar Energy Application ( Small Scale).
- Photovoltaic Panel.
□ Another metal panel is attached to the bottom P-type
layer of silicon to be connected to the return current
and feed electrons back into the cell.
□ Electrons in the silicon cells are knocked
loose by the sun & forced to travel from
the bottom to the top layer.
□ Metal conductor strips which run along
the top n-type silicon layer capture the
freed electrons and conentrate them into
a current, routed through a circuit to
produce electrical power.
□ An anti-reflective sheet or coating placed on top of
or directly adhered to the silicon sandwich. This
sheet reduces the amount of sunlight reflected off
the glass allowing more sunlight to hit the cell and
increasing the panel's efficiency.

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2.5 Modern Solar Energy Application ( Small Scale).
- Solar Collector Panel.
□ Solar panel collects the sun’s energy in the
form of heat and transfers it to the storage
facility and heat exchanger.
□ Recommended size ranges from 1/3 to 1/2
of the net floor area.
□ The heat transfer medium may be air, water
or other liquids.
□ It carries the collected heat energy from the
solar panel to the heat exchange equipment
or the storage facility.

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2.5 Modern Solar Energy Application ( Small Scale).
- Solar Collector Panel.
□ Liquid system uses pipes for circulation and
distribution (with antifreeze and anti corrosion
additives as required ).
□ Air system requires larger space for ductwork
and larger collector panel due to its less
efficient heat transfer than water.
□ Insulated storage facility holds heat to be used
when required.
□ It may be in the form of a tank filled with water,
other liquids, a bin of rocks or salt (for air
system).

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2.6 Application of Solar Energy.
What is solar
energy used for?
Where is it used? Which solar
technologies are
used?
Which secondary
technologies are
used?
Heating - Water Homes Glazed flat plate
collector
Heat exchanger
Hot water tank
Commercial Liquid based
collector
Heat exchanger
Hot water tank
Agriculture Glazed flat plate
collector
Heat exchanger
Hot water tank
Crop drying Agriculture Air based collector
Detoxifying
water
Industrial /
Municipal
Photocatalyst for
oxidation
UV lamp for
back-up.
Heating
swimming pool
Outdoor pools Unglazed flat
plate collector

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2.7 Advantages of Solar Energy.
1. Saves Money.
□ After the initial investment has been recovered, the
energy from the sun is practically free.
□ It is not affected by the supply and demand of fuel nd
therefore not subjected to any increase in price of gasoline.
□ Excess electrity can be sold to utility company by
connecting to the national electrical grid.
2. Environmental Friendly.
□ Solar energy is clean, renewable and sustainable, helping to
protect our enironment.
□ It does not pollute our air by releasing CO2, Nitrogen Oxide,
Sulphur Dioxide or Mercury.
3. Independent / Semi-independent.
□ It can operate entirely independently or be connected to the grid.
4. Low / No Maintenance.
□ It is virtually maintenance-free and will last forever.
□ Once installed, there is no recurring cost.

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2.8 Disadvantages of Solar Energy.
1. High Cost.
□ The initial cost is very high due to the cost of semi conducting
materials in the system.
□ The cost of solar energy still too high compared to conventional
utility-supplied electricity.
1. Space Requirement.
□ Solar panels require large area for installation.
3. Efficiency.
□ Its efficiency is dependent on the location of the sun & affected by
clouds or pollution in the air.
□ Increase in efficiency can be achieved by using a sun-tracking
motor but at additional high cost.
□ Solar energy is not produced at night. Any additional backup
batteries will increase the price further.

32.  Power generated from
water, (large-scale dams),
 approximately 20 percent
of global energy production,
 the greatest contributors of
all renewable energy
sources.
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33.  At peak times of electrical demand- water releases
from the reservoir behind the dam through a turbine,
generating hydroelectricity.
 During periods of lower electrical demand-, excess
electrical capacity can be used to pump water into the
higher reservoir, effectively “storing” the electricity for
later use.
 Pumped-storage hydroelectric reservoirs also are
used sometimes to store electricity produced by thermal
plants for use during peak times
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34. Advantages:
 ability to handle both seasonal and daily peak loads.
Disadvantages:
 People may need to be displaced from areas where a
dam is planned.
 Has a harmful effect on aquatic life
 Reservoirs may produce substantial amounts of
carbon dioxide and methane gas because of the
decay of plant material in areas inundated and goes
through the turbines and affect them.
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35.  Geothermal energy is
energy obtained by tapping
the heat of the earth itself,
usually from kilometers
deep into the Earth's crust.
 It is expensive to build a
power station but operating
costs are low resulting in
low energy costs for suitable
sites.
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36.  is a form of hydropower that
converts the energy of tides into
useful forms of power - mainly
electricity.
 Tidal energy is one of the oldest
forms of energy used by humans
 tidal power has traditionally
suffered from relatively high cost
and limited availability of sites with
sufficiently high tidal ranges or
flow velocities, thus constricting its
total availability
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37. How does it work??
 Tide mills consisted of a storage
pond, filled by the incoming (flood)
tide through a sluice and emptied
during the outgoing (ebb) tide
through a water wheel. The tides
turned waterwheels, producing
mechanical power to mill grain.
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38.  Wave energy is: the transport of
energy by ocean surface waves,
and the capture of that energy to do
useful electricity generation.
 The energy from waves alone could
supply the world's electricity needs.
The total power of waves breaking
on the world's coastlines is
estimated at 2 to 3 million
megawatts The problem is how to
harness wave energy efficiently
and with minimal environmental,
social, and economic impacts.
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39.  Wave energy devices extract
energy directly from the surface
motion of ocean waves or from
pressure fluctuations below the
surface.
 Wave energy is an irregular
oscillating low-frequency energy
source. They are a powerful source
of energy, but are difficult to
harness and convert into electricity
in large quantities. The energy
needs to be converted to a 60 Hertz
frequency before it can be added
to the electric utility grid.
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41.  Biofuel is a type of fuel whose
energy is derived from
biological carbon fixation.
 Biofuels include fuels derived
from biomass conversion, as
well as solid biomass, liquid
fuels and various biogases.
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42.  Biomass energy is energy produced by
burning biomass. Biomass is biological
material derived from living, or recently living
organisms or dead organisms like plants,
waste and alcohol mostly.
 the most economical type of biomass for
generating energy comes from residues,
organic byproducts of food, fiber and forestry
including sawdust, rice husks, wheat straw,
corn stalks and bagasse (sugar cane
residue).
 Biomass fuels burn to generate heat, which is
converted to mechanical energy using either
a steam or gas turbine.
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43. 43

44. three other types of biomass electricity-generation
systems:
 direct-fired systems: biomass fuel is burned in
a boiler to produce high-pressure steam, which
then drives turbines to produce electricity. they
tend to be small scale and are not very
efficient.
 Gasification system: far more efficient, reaching
60 percent, versus only 20-40 percent for some
direct-fired plants
 Modular system
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45.  liquid hydrogen used in fuel cells.
 a fuel cell uses a catalyst to create a
reaction between hydrogen from a fuel
and oxygen from the air to generate
electricity, with the only byproduct being
water.
 Large automotive manufacturers,
such as General Motors and Daimler
Chrysler, also started investing in fuel-
cell companies and began to design
concept fuel-cell powered vehicles
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46. Three ways to produce hydrogen:
•Natural gas, coal, wood and organic waste
burn with air and steam at extremely high
temperatures. When cooled, the resulting
gases contain a significant amount of
hydrogen.
•An electrical current is passed between two
electrodes (an electrolyzer) immersed in
water. Hydrogen rises up from the negative
electrode and oxygen from the positive
electrode.
•Some bacteria reportedly produce hydrogen,
but this method has yet to be exploited
commercially.
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