::WIND
In recent years, wind energy has become one of the most economical renewable
energy technologies. Today, electricity generating wind turbines employ proven
and tested technology, and provide a secure and sustainable energy supply. At
good, windy sites, wind energy can already successfully compete with
conventional energy production. Many countries have considerable wind resources,
which are still untapped.
A technology which offers remarkable advantages is not used to its full
potential:
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Wind energy produces no greenhouse
gases.
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Wind power plants can make a significant contribution to the regional
electricity supply and to power supply diversification.
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A very short lead time for planning and construction is required as compared to
conventional power projects.
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Wind energy projects are flexible with regard to an increasing energy demand -
single turbines can easily be added to an existing park.
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Finally, wind energy projects can make use of local resources in terms of
labour, capital and materials.
The technological development of recent years, bringing more efficient and more
reliable wind turbines, is making wind power more cost-effective. In general,
the specific energy costs per annual kWh decrease with the size of the turbine
notwithstanding existing supply difficulties.
Many African countries expect to see electricity demand expand rapidly in coming
decades. At the same time, finite natural resources are becoming depleted, and
the environmental impacts of energy use and energy conversion have been
generally accepted as a threat to our natural habitat. Indeed these have become
major issues for international policy.
Many developing countries and emerging economies have substantial unexploited
wind energy potential. In many locations, generating electricity from wind
energy offers a cost-effective alternative to thermal power stations. It has a
lower impact on the environment and climate, reduces dependence on fossil fuel
imports and increases security of energy supply.[
For many years now, developing countries and emerging economies have been faced
with the challenge of meeting additional energy needs for their social and
economic development with obsolete energy supply structures. Overcoming supply
bottlenecks through the use of fossil fuels in the form of coal, oil and gas
increases dependency on volatile markets and eats into valuable foreign currency
reserves. At the same time there is growing pressure on emerging newly
industrialized countries in particular to make a contribution to combating
climate change and limit their pollutant emissions.
In the scenario of alternatives, more and more developing countries and emerging
economies are placing their faith in greater use of renewable energy and are
formulating specific expansion targets for a ‘green energy mix’. Wind power,
after having been tested for years in industrialized countries and achieving
market maturity, has a prominent role to play here. In many locations excellent
wind conditions promise inexpensive power generation when compared with costly
imported energy sources such as diesel. Despite political will and considerable
potential, however, market development in these countries has been relatively
slow to take off. There is a shortage of qualified personnel to establish the
foundations for the exploitation of wind energy and to develop projects on their
own initiative. The absence of reliable data on wind potential combined with
unattractive energy policy framework conditions deters experienced international
investors, who instead focus their attention on the expanding markets in Western
countries.
It is only in recent years that appreciable development of the market potential
in developing countries and emerging economies has taken place. The share of
global wind generating capacity accounted for by Africa, Asia and Latin America
reached about 20% at the end of
2008, with an installed capacity of 26 GW. This is attributable above all to
breathtaking growth in India and China: these two countries alone are
responsible for 22 GW. This proves that economic use of wind energy in
developing countries and emerging economies is possible, and also indicates that
there is immense potential that is still unexploited.
The Technology
Wind power is the conversion of
wind energy into electricity or mechanical energy using wind
turbines.
The power in the wind is extracted by allowing it to blow past moving blades
that exert torque on a rotor. The amount of power transferred is dependent
on the rotor size and the wind speed.
Wind turbines range from small four hundred watt generators for residential
use to several megawatt machines for wind farms and offshore. The small ones
have direct drive generators, direct current output, aeroelastic blades,
lifetime bearings and use a vane to point into the wind; while the larger
ones generally have geared power trains, alternating current output, flaps
and are actively pointed into the wind.
Direct drive generators and aeroelastic blades for large wind turbines are
being researched and direct current generators are sometimes used.
Since wind speed is not constant, the annual energy production of a wind
converter is dependent on the capacity factor. A well sited wind generator
will have a capacity factor of about 35%. This compares to typical capacity
factors of 90% for nuclear plants, 70% for coal plants, and 30% for thermal
plants.
As a general rule, wind generators are practical where the average wind
speed is 4.5 m/s or greater. Usually sites are pre-selected on the basis of
a wind atlas, and validated with on site wind measurements.
Wind energy is plentiful, renewable, widely distributed, clean, and reduces
greenhouse gas emissions if used to replace fossil-fuel-derived electricity.
The intermittency of wind does not create problems when using wind power at
low to moderate penetration levels
PCRET Work
Pakistan Council of
Renewable Energy Technology (PCRET) has successfully completed installation of
wind turbines under a PSDP Project "Electrification of Remote Coastal Villages
is using Wind Energy" by installing 155 micro wind generators, electrifying more
than 1600 houses. Under the Project 0.5, 1.0, 3.2, 5.0 6.0 and 10 K.W wind
turbines were imported from China, USA, Spain, Germany and Australia. They have
been installed in the coastal belt of Arabian sea in the provinces of Sindh and
Balochistan. PCRET technical personal has acquired training in assembling and
installation of these wind generators through the courtesy of Peoples Republic
of China. These wind turbines are functioning successfully and supervisory
service, in case of operation and maintenance is provided to the end-users by
the PCRET technical staff.
Presently, PCRET
intends to acquire expertise in design and fabrication of different components
of wind turbines in the range of 5kw and 10kw power generation capacities.
Technology transfer for this purpose is required to be made from leading
countries in wind energy technology i.e. China, USA and others.
Harnessing the Viability
There are hundreds of
villages in the coastal belt on the Arabian Sea that need to be electrified by
wind energy as they are not included in the priority program of the Government
for rural electrification due to difficult terrain, Whereas viability of the
wind power generation has already been established by installing 155 small wind
turbines in the area. It can be adjudged from the fact that a large number of
applications are pending with PCRET for installation of wind turbines.
Potential
The energy derived
from wind power over the globe till December 2008 exceed 100,000 MW, which
represents 40% of the total energy derived from other sources of Renewable
Energy (Hydro, Solar, Biomass Geo –Thermal etc.) all over the world.
The coastal belt in
Pakistan has power generation potential of more than 50,000 MW that can be
harnessed through appropriate wind machine for which local manufacturing of wind
turbines is necessary in order to save precious foreign exchange.
Feasibility study on
the availability of wind velocity at sustainable speed for running wind turbine
in the coastal belt of Arabian Sea located in the Provinces of Balochistan and
Sindh of Pakistan has been carried out. It has been found that the wind corridor
is available from Gharo to Keti Bandar in Thatta district of the Sindh Province,
having a power generation potential of 50,000 MW. Similar is the case of
Lasbella District of Balochistan Province, where wind at a sustainable speed,
good for power generation is available with little variation in the seasons (5
meters per second in winter and 8 meters per second in the summer).
ACHIEVEMENT OF PCRET
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155 wind-generating
units of 0.5 kw to 10 kw power generation capacity have been installed for the
neglected segment of the society.
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About 1600 houses of
remote coastal villages in Sindh & Balochistan have been electrified.
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More than 400
applications for wind electrification from remote coastal village, are pending
with the PCRET due to successful completion of first phase of the project.
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There is a need for
further dissemination of technology, as most of the villages in the coastal
areas, particularly, in Lasbela district of Balochistan, Badin and Thatta
district in Sindh are still deprived of the basic amenities of life including
electricity.
The following measures
need to the adopted for better and smooth functioning of wind turbines.
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Selection of sites
must be need based and on available potential (wind speed) interest, cooperative
aptitude of beneficiary and will.
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Wind Turbine (stand
alone system) are to be provided to those villages, which are physically
inaccessible and economically feasible for supplying electricity from the
national grid.
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Projects on “Wind
Energy” for meeting the country’s energy needs should be encouraged particularly
for electrification of remote coastal villages.
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Local manufacture of
wind turbines should be encouraged for economic exploitation of the wind energy
potential available in the country.
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Government should
facilitate the local manufacturers of wind turbines by exempting taxes on import
of raw material like permanent magnet, copper wire, polymers etc. required for
local manufacturer of wind turbines.