Newsletter and Technical Publications
Alternative Technologies for Freshwater Augmentation
in West Asia>
The costs for the construction, operation and maintenance of this technology is closely related
to the economic feasibility of utilizing wind energy. It is noted that the notion that wind energy
is free is not exactly true. In fact, the wind is free, but not the energy. From a scientific and
economic perspective, wind energy becomes free after the system is purchased,
installed and generated sufficient quantities of energy to have covered its
In fact, it is not
easy to accurately determine the cost of wind energy because of the following
- The cost of wind power is related to several variables,
the most important being location, wind intensity and frequency, and
coincidence of windy periods with the periods of energy consumption;
- The type, size, energy output and quality of the
system, and its conformity with the wind characteristics at the site of use;
- The system use and needed equipment (pipes, pumps,
water reservoirs, transformers, electric batteries, etc.), as well as the
height and sturdiness of the tower.
Nevertheless, one of the following two approaches is typically used to estimate wind energy costs,
This approach is based on determination of the cost of one kilowatt of the nominal capacity
for the wind energy system. Most manufacturing
companies try to reduce this cost by using simpler designs and following
large-scale, serial production techniques.
This approach is based on determination of the cost of one square meter of the area of the system
rotor. Most manufacturing companies also try to reduce the costs further through facilitating optimal
design and use of the system.
The first approach is
recommended, as it give a better idea of the systemís benefits in regard to its
design and output. It also assists the
user to avoid purchasing a system with a large rotor, but a low capacity.
Experiments and information obtained from the use of small wind energy systems have
demonstrated that the cost of a fully successful wind energy system (including
system, tower, batteries and converters), being used independently of any other
power source, is between US$ 2.50-5.00/watt of the systemís nominal
capacity. This cost is reduced to US$
1.50-2.50/watt when the batteries and converter are not used. Thus, the price of one kilowatt of wind
energy with this system ranges between US$ 1,500-5,000. Using this value, the price of a ten
kilowatt capacity wind energy system can range between US$ 15,000-50,000,
depending on the system type, quality and needed equipment. It is noted that the price of good batteries
can total up to 40% of the price of the total system.
The initial cost to construct a submerged electric pump unit
utilizing wind energy (7 m diameter rotor) is US$ 40,000 in the Sultanate of Oman.
The following simplified computation is presented for
estimating the cost of pumping water using traditional wind energy systems, as
well as modern systems having similar production characteristics in regard to
A = Average lifetime of the system (years);
B = 8,760 hours/year;
C = System capacity in terms of annual average wind speed at the operation site
The cost is increased with modern systems, due primarily to the required system accessories
for pumping the water (pump, cables, electrical fixtures, etc). The cost is about US Ĺ cent/m3 of
water for traditional systems and about US 1 cent/m3 for modern
systems. This cost is competitive with
other technologies typically applied in remote areas far from sources of
electrical power or oil. This is particularly the case if it is considered that the actual lifetime of
conventional systems is unlimited, whereas some maintenance and replacement of
batteries is required for the modern systems that depend on the generation of
Effectiveness of the Technology
On one hand, the efficiency of this technology is dependent on its quality, and the quality of the
conventional multiple blade systems has proven effective over many years.
This technology is easy to maintain and has a negligible wear factor. Depending on the water purity,
only the pump seals must be replaced every 3-5 years. The modern two- and three-blade systems are
considered experimental, being duplicated from European designs. Thus, there has not yet been
sufficient time to evaluate their effectiveness over long durations of 10 years or longer.
On the other hand,
the effectiveness of this technology also is dependent the availability of wind
energy to satisfy their operational requirements.
It obviously is pointless to install a system requiring a certain
minimum wind speed in areas where this wind speed does not occur for long
durations over a given year, or where it never occurs.
Even if the needed minimum wind speed occurs
during certain periods over the annual cycle, lower wind speeds for the
remainder of the year result in a lower return for the wind energy system.
Thus, in addition to the nominal capacity of
the system, the occurrence and frequency of different wind speeds also must be
considered. This includes computing the
system efficiency and productivity, based on the results of wind speed measures
carried out at its designated installation site over at least a five-year period.
A review of the available wind measurements
from some of the meteorological stations in the countries of West Asia clearly
indicates that there are several locations enjoying appropriate wind speeds for
efficient operation of this technology.
This technology is best utilized in areas with suitable wind activity throughout the year, and
with shallow groundwater depths. It
encourages the wise use of groundwater resources, because of its limited
pumping capacity controlled by its technical specifications and wind speed
The technology is ideal for remote arid and semi-arid areas located far from electric power
sources. Nevertheless, it also can be
used in an effective and economically- feasible manner in areas where electric
power is available, primarily because of constant increases in energy prices.
The technology is not only utilized to withdraw water from wells, but also from
canals, rivers and dams to reservoirs above ground level, as well as to convey
the water to remote areas. The
technology also is used to improve the aquatic environment for fisheries, by
increasing the dissolved oxygen content of the water by pumping it from fish
farms and conveying it back to the tank.
It also is suitable for protecting the environment and reducing air
pollution caused by the exhaust from other types of energy that utilize oil
The advantages of this technology are as follows:
- It is clean, and does not introduce pollutants to the environment;
- It exhibits an extended lifetime (some systems in the Al- Qalmoun area in Syria have been operating
for more than 50 years);
- It has little maintenance requirements;
- The system is usually paid for at installation, with no further monthly or yearly payments
(except for the low maintenance costs).
There are no specific disadvantages to the use of this technology, except its dependence on
the availability of wind. This means
that the well discharge is sensitive to fluctuations in wind speed.
This disadvantage can be overcome, however,
if a pre-study is undertaken to determine the character of the prevailing wind
patterns in a given location. A
well-prepared farmer can install a suitable system, taking into consideration
such factor as the wind patterns and characteristics, farm size and the types
of vegetation and their irrigation requirements.
Such information also will assist the farmer to select the
appropriate size for the system(s) needed, as well as ensuring that the water
reservoirs can store water volumes that can fully meet the farmís water
It is noted that the system susceptibility to changes in wind speeds can be overcome with modern
systems that use electrical submerged pumps.
The wind energy systems generate the needed electricity and store it in
batteries, to be used later to run the pumps during periods of little or no wind.
The initial response to the use of this technology in countries in the Arab region was very
encouraging. A subsequent decline in interest can be
attributed to hydrogeological (fall of water table) and financial (increased
installation costs) reasons. Nevertheless, the technology is relatively popular because of its low
environmental impacts. Its comeback
also is attributed to its ability to generate electrical power that can be used
to pump water via electric pumps. The electric pumps can withdraw water from greater depths than can
the initial mechanical pumps.
Further Development of the Technology
Many experiments with the development and use of this technology have been carried out in the
industrial countries of Europe, United States of America and the Russian
Federation. In the Arab region, few
experimental efforts have been undertaken, although some efforts to develop the
technology and to establish testing laboratories were undertaken in Syria,
Jordan and some Gulf countries. These
latter developmental effort have generally concentrated on the following topics:
- Developing the system rotors to operate at low wind
speeds and with a high capacity. The
nominal speed needed to operate the wind energy system is generally still
higher than the prevailing wind speeds in the region.
Thus, most of the available system still exhibit a relatively
small economic return in most areas;
- Reducing costs by using materials resistant to wear at
high wind speeds and their vortices;
- Increasing the pump efficiency, in order to increase
pumping capacity and the water head to facilitate pumping the water to higher levels.
Al-Nozom Al-Tabeaya Company
Dr. Nawras Al-doqer
P.O.BOX : 33073
Abou Romanah (near agricultural engineers syndicate)
Controller General Information and Public Awareness Center
Ministry of Water Resources
P.O.BOX : 2575 RUWI
Sultanate of Oman
Workshop of Mohammed Wahib Al-Nafori
Tel: 7221898-7001897 (home)
Tel: 7220690 (workshop)
ACSAD. Syria country report: Study and development project of Arab water technologies.
ACSAD, Damascus, Syria.
ACSAD.†1983. General report: Study and development project of Arab water technologies.
ACSAD, Damascus, Syria.
ACSAD. 1983. The use of wind energy: Studies of Al-Hamad Basin.
ACSAD, Damascus, Syria.