Monday, June 29, 2009
Friday, May 8, 2009
Logistics Insight Asia, 1/11/2008
OIL & GAS LOGISTICS
Logistics Insight Asia, 1/11/2008
G VENKATESH unravels the complex logistics networks that serve the vital oil and gas sector.
Pipelines, tankers, trucks and trains; oil & gas companies, tanker operators, retail outlets, endconsumers, 3PLs, automation solutions providers; international organizations, national governments and policymakers. The logistics network in the oil and gas sector is a complex one, with the entities influencing and being influenced by each other. Figure 1 depicts the principal flows of crude oil and natural gas. (Note: the numbers pertain to trade volumes in 2003, and these have increased during the last five years). Crude oil flows originate largely in the Middle East and move northwards to Japan, China, Europe and the US. A sizeable chunk of the natural gas flows originates close to the Arctic Circle and wends its way southwards to the consumers in the developed countries of the northern temperate region.
Crude oil and refined products (not depicted in the figure) move internationally in oil tankers (big ones for long trans-oceanic journeys to optimize the expenses, and smaller ones for shorter journeys), or even via overland pipelines. Natural gas exports wend their way either via pipelines (subsea or overland) or via methane tankers subsequent to liquefaction in LNG plants. Prominent examples of subsea pipelines are those linking the Norwegian off shore gas fields in the North Sea to the European terminals (shown by the thick redwhite arrow), or linking North Africa to Italy. There are intra-national flows as well. Gas pipelines, emanating from the gasifi cation plants which receive LNG from methane tankers, or from a country’s off shore or onshore gas fields, convey natural gas directly to industrial, commercial and domestic end-users within the country. And oil pipelines convey crude oil from the unloading terminals at ports and from oilfields in the country to refineries. Crude oil and refined products would move in tankers along rivers and coastlines and across lakes, and also by rail and road to replenish the retail outlets within the country (or, in the case of crude oil, to provide raw feed to the refineries in the same country). Likewise, there are flows from within the country – its oilfields, gas fields or refineries – destined for export. Here, we differentiate between the multimodal ones terminating at loading bays or liquefaction plants at/near portsites (and take the maritime route thereafter), and the ones along international pipelines or rivers which cross national borders. Figure 2 presents a simplified schematic sketch of logistics in the oil and gas sector of a hypothetical country (indicated with pink background), which is bounded by country B to its south-west and on all other sides by an ocean. Thus, it has the benefits of availing of maritime trade via its five ports. A river flows across the boundary between the two countries, and thus facilitates inland water transport (exports) of refined products.
The end-use market – industry, households and transportation – is linked to the refineries and gasification plant by a mix of road and rail transport and overland pipelines. The country finds it economical to liquefy all its natural gas (taken into the liquefaction plant by a subsea pipeline) and export the same by methane tankers. The domestic natural gas needs are supplied by imports. Once again, the country perhaps finds it economical to export some of its crude oil. The refineries source their inputs from both the domestic production and imports.Logistics costs (all modes taken together) accounted for something between 5 percent and 10 percent of the total value of the oil in 2005 (it is around two US cents per gallon handled). However, with oil prices shooting up, the percentage share of logistics cost in the total production cost has declined.
PIPELINES FLOWS It is highly economical to convey crude oil and refined petroleum products (gasoline, kerosene, diesel, aviation fuel, ethanol, etc) via terrestrial pipelines owing to the lower cost and the higher carrying capacity thereof. However, road and rail transport of oil and refi ned petroproducts also exists.It is not exactly known where the first oil pipeline in the world became operational and in a manner typical of the cold war era (which seems to be starting again, with natural gas a trigger, incidentally), the Americans and the Russians stake claim to this “honor”. However, it is widely agreed that it was Dmitri Mendeleev of the Periodic Table fame who first suggested in the 1860s that petroleum could and should be transported via pipelines. From the 1860s, the world has come a long way, and pipeline transportation has become commonplace. A total of 265,440 km of oil and natural gas pipelines (as at the end of June 2008) exists in 37 Asian countries, of which roughly 45 percent carry oil/refi ned products/condensate. Natural gas flows through 144,741 km of these pipelines. Crude oil pipelines are generally made of steel or plastics, while natural gas pipelines are made exclusively of carbon steel. A complete network, in general, would have few long and large transportation pipelines between many shorter and smaller gathering pipelines (originating from the sources) on the upstream and distribution pipelines (leading to tanks, storage facilities, and endusers) on the downstream. It need not be overemphasized that in the oil and gas sector, while the processing sites and the loading and unloading terminals are certainly key nodes of the process chain, the arteries which keep the system functioning ship-shape are the pipelines. While corrosion is an enemy to be combated, pipelines are also targeted by vandals and terrorists; it happened in Nigeria recently when rebels burst oil pipelines to disrupt the operations of the foreign oil and gas companies in the country. Examples of pipeline automation systems are numerous. In Indonesia, for instance, Siemens set up SCADA/ MIS systems to remotely monitor a 540-kilometre pipeline carrying natural gas, and from a control centre personnel can be forewarned of pipeline failures.
MARINE OIL TANKERS Long-distance conveyance of crude oil, refined products and LNG which cannot be accomplished via pipelines, takes place by marine tankers. Maritime transport of crude oil and refined products accounts for over 60 percent of the total supply. Exporters avail of the services of tanker operators – Teekay Corporation, Frontline, Overseas Shipholding Group being among the leading names in the business. However, some oil and gas majors would also prefer to own and operate their own tankers.
Marine tankers can be classified on the basis of purpose into crude oil tankers and (refined) product tankers, and on the basis of size (capacity) into six classes – General Purpose, Medium Range, Large Range I, Large Range II, Very Large Crude Carriers, Ultra Large Crude Carriers (ULCC).The tankers among themselves, transported about 1.85 billion tonnes of crude oil and 0.66 billion tonnes of refined products in 2005, averaging a distance of about 8000 km per tonne transported. Compared to 1970, this reflects a 70 percent rise in the cargo and an 80 percent growth in the tonnagekilometers clocked by the oil tankers. Competition among tank owners has resulted in a decrease in the costs incurred by the exporters in shipping crude oil and refined products. Tankers have always raised the eyebrows of environmentalists. However, over the last few years, as a report from the United Nations Environment Project states, 63 percent less oil is entering the global marine environment than in the mid- 1980s, primarily due to a drastic drop in tanker accidents over the last two decades. All is not hunky dory in Asia, however, with many countries turning a blind eye to environmental concerns. Coastal pollution and its adverse fallouts in some pockets of the Indian Ocean are alarming indeed.
TRUCKS & TRAINS Crude oil and refined products are also moved from source to destination by trucks and trains. Tanker trucks carry gasoline, diesel, aviation fuel as supplies to the transportation sector, or LPG for use in households (supplies to the domestic sector), or fuel and furnace oils to the industrial sector. They may range in capacity from 3800 liters (used to carry pressurised LPG) to over 40,000 liters (other petroleum products). Likewise, there are tank cars or tank wagons which ply on rails.There are either third-party logistics service providers – with or without their own fleet of vehicles – which undertake these operations for companies in the oil and gas sector. Of course, some or most of the companies in the sector do not totally outsource their logistics operations and maintain their own fleet of vehicles as well. Accidents associated with road tankers were commonplace in the past – owing to a combination of technical and non-technical reasons – and have not been eliminated totally. Regulations on safety have become more stringent with time, and design specifications have ensured that safety is not left to chance.Trucks and trains will continue to be an integral part of the oil and gas sector logistics networks, serving to move materials especially on the last lap of the journey. Tanker age and thereby engine efficiency are critical parameters when one needs to ensure fuel efficiency and safety. Of course, one needs to ensure that the transportation infrastructure – roads and railways – supports safe and effi cient movement of crude oil and refi ned products within countries.
MAZE OF MOVEMENTS Every global oil and gas major would be availing of and managing a complex and diverse logistics network around the world. When Logistics Insight Asia quizzed BP about the company’s logistics operations around the world, the response was: “It depends on where we are. In the US we have huge oil and gas production, refinery networks, logistics chains and retail networks, so our pipelines and transport systems are very different from, for example, China. In China we have several petrochemicals plants which are fed by pipeline and some products leave by pipeline, but some are trucked out, or shipped. We also supply LPG and LNG, aviation fuels, and manage retail networks there.”GAC is one player in oil and gas logistics that has diversified far and wide in Asia and Africa, from its base in Kuwait. Table 1 indicates the range of services which a 3PL like GAC can provide for its clients. Oil and gas companies can benefit financially by contracting logistics operations – in part or wholly – to 3PLs. It is often a strategic business decision which enables the company to focus on its core operations, while the 3PL handles the logistics efficiently and economically – and often much better than how the company would have done it.
This whole text has been copied from the following link and is authored by someone else as stated in the opening lines of this article.
OIL & GAS LOGISTICS
Logistics Insight Asia, 1/11/2008
Logistics Insight Asia, 1/11/2008
G VENKATESH unravels the complex logistics networks that serve the vital oil and gas sector.
Pipelines, tankers, trucks and trains; oil & gas companies, tanker operators, retail outlets, endconsumers, 3PLs, automation solutions providers; international organizations, national governments and policymakers. The logistics network in the oil and gas sector is a complex one, with the entities influencing and being influenced by each other. Figure 1 depicts the principal flows of crude oil and natural gas. (Note: the numbers pertain to trade volumes in 2003, and these have increased during the last five years). Crude oil flows originate largely in the Middle East and move northwards to Japan, China, Europe and the US. A sizeable chunk of the natural gas flows originates close to the Arctic Circle and wends its way southwards to the consumers in the developed countries of the northern temperate region.
Crude oil and refined products (not depicted in the figure) move internationally in oil tankers (big ones for long trans-oceanic journeys to optimize the expenses, and smaller ones for shorter journeys), or even via overland pipelines. Natural gas exports wend their way either via pipelines (subsea or overland) or via methane tankers subsequent to liquefaction in LNG plants. Prominent examples of subsea pipelines are those linking the Norwegian off shore gas fields in the North Sea to the European terminals (shown by the thick redwhite arrow), or linking North Africa to Italy. There are intra-national flows as well. Gas pipelines, emanating from the gasifi cation plants which receive LNG from methane tankers, or from a country’s off shore or onshore gas fields, convey natural gas directly to industrial, commercial and domestic end-users within the country. And oil pipelines convey crude oil from the unloading terminals at ports and from oilfields in the country to refineries. Crude oil and refined products would move in tankers along rivers and coastlines and across lakes, and also by rail and road to replenish the retail outlets within the country (or, in the case of crude oil, to provide raw feed to the refineries in the same country). Likewise, there are flows from within the country – its oilfields, gas fields or refineries – destined for export. Here, we differentiate between the multimodal ones terminating at loading bays or liquefaction plants at/near portsites (and take the maritime route thereafter), and the ones along international pipelines or rivers which cross national borders. Figure 2 presents a simplified schematic sketch of logistics in the oil and gas sector of a hypothetical country (indicated with pink background), which is bounded by country B to its south-west and on all other sides by an ocean. Thus, it has the benefits of availing of maritime trade via its five ports. A river flows across the boundary between the two countries, and thus facilitates inland water transport (exports) of refined products.
The end-use market – industry, households and transportation – is linked to the refineries and gasification plant by a mix of road and rail transport and overland pipelines. The country finds it economical to liquefy all its natural gas (taken into the liquefaction plant by a subsea pipeline) and export the same by methane tankers. The domestic natural gas needs are supplied by imports. Once again, the country perhaps finds it economical to export some of its crude oil. The refineries source their inputs from both the domestic production and imports.Logistics costs (all modes taken together) accounted for something between 5 percent and 10 percent of the total value of the oil in 2005 (it is around two US cents per gallon handled). However, with oil prices shooting up, the percentage share of logistics cost in the total production cost has declined.
PIPELINES FLOWS It is highly economical to convey crude oil and refined petroleum products (gasoline, kerosene, diesel, aviation fuel, ethanol, etc) via terrestrial pipelines owing to the lower cost and the higher carrying capacity thereof. However, road and rail transport of oil and refi ned petroproducts also exists.It is not exactly known where the first oil pipeline in the world became operational and in a manner typical of the cold war era (which seems to be starting again, with natural gas a trigger, incidentally), the Americans and the Russians stake claim to this “honor”. However, it is widely agreed that it was Dmitri Mendeleev of the Periodic Table fame who first suggested in the 1860s that petroleum could and should be transported via pipelines. From the 1860s, the world has come a long way, and pipeline transportation has become commonplace. A total of 265,440 km of oil and natural gas pipelines (as at the end of June 2008) exists in 37 Asian countries, of which roughly 45 percent carry oil/refi ned products/condensate. Natural gas flows through 144,741 km of these pipelines. Crude oil pipelines are generally made of steel or plastics, while natural gas pipelines are made exclusively of carbon steel. A complete network, in general, would have few long and large transportation pipelines between many shorter and smaller gathering pipelines (originating from the sources) on the upstream and distribution pipelines (leading to tanks, storage facilities, and endusers) on the downstream. It need not be overemphasized that in the oil and gas sector, while the processing sites and the loading and unloading terminals are certainly key nodes of the process chain, the arteries which keep the system functioning ship-shape are the pipelines. While corrosion is an enemy to be combated, pipelines are also targeted by vandals and terrorists; it happened in Nigeria recently when rebels burst oil pipelines to disrupt the operations of the foreign oil and gas companies in the country. Examples of pipeline automation systems are numerous. In Indonesia, for instance, Siemens set up SCADA/ MIS systems to remotely monitor a 540-kilometre pipeline carrying natural gas, and from a control centre personnel can be forewarned of pipeline failures.
MARINE OIL TANKERS Long-distance conveyance of crude oil, refined products and LNG which cannot be accomplished via pipelines, takes place by marine tankers. Maritime transport of crude oil and refined products accounts for over 60 percent of the total supply. Exporters avail of the services of tanker operators – Teekay Corporation, Frontline, Overseas Shipholding Group being among the leading names in the business. However, some oil and gas majors would also prefer to own and operate their own tankers.
Marine tankers can be classified on the basis of purpose into crude oil tankers and (refined) product tankers, and on the basis of size (capacity) into six classes – General Purpose, Medium Range, Large Range I, Large Range II, Very Large Crude Carriers, Ultra Large Crude Carriers (ULCC).The tankers among themselves, transported about 1.85 billion tonnes of crude oil and 0.66 billion tonnes of refined products in 2005, averaging a distance of about 8000 km per tonne transported. Compared to 1970, this reflects a 70 percent rise in the cargo and an 80 percent growth in the tonnagekilometers clocked by the oil tankers. Competition among tank owners has resulted in a decrease in the costs incurred by the exporters in shipping crude oil and refined products. Tankers have always raised the eyebrows of environmentalists. However, over the last few years, as a report from the United Nations Environment Project states, 63 percent less oil is entering the global marine environment than in the mid- 1980s, primarily due to a drastic drop in tanker accidents over the last two decades. All is not hunky dory in Asia, however, with many countries turning a blind eye to environmental concerns. Coastal pollution and its adverse fallouts in some pockets of the Indian Ocean are alarming indeed.
TRUCKS & TRAINS Crude oil and refined products are also moved from source to destination by trucks and trains. Tanker trucks carry gasoline, diesel, aviation fuel as supplies to the transportation sector, or LPG for use in households (supplies to the domestic sector), or fuel and furnace oils to the industrial sector. They may range in capacity from 3800 liters (used to carry pressurised LPG) to over 40,000 liters (other petroleum products). Likewise, there are tank cars or tank wagons which ply on rails.There are either third-party logistics service providers – with or without their own fleet of vehicles – which undertake these operations for companies in the oil and gas sector. Of course, some or most of the companies in the sector do not totally outsource their logistics operations and maintain their own fleet of vehicles as well. Accidents associated with road tankers were commonplace in the past – owing to a combination of technical and non-technical reasons – and have not been eliminated totally. Regulations on safety have become more stringent with time, and design specifications have ensured that safety is not left to chance.Trucks and trains will continue to be an integral part of the oil and gas sector logistics networks, serving to move materials especially on the last lap of the journey. Tanker age and thereby engine efficiency are critical parameters when one needs to ensure fuel efficiency and safety. Of course, one needs to ensure that the transportation infrastructure – roads and railways – supports safe and effi cient movement of crude oil and refi ned products within countries.
MAZE OF MOVEMENTS Every global oil and gas major would be availing of and managing a complex and diverse logistics network around the world. When Logistics Insight Asia quizzed BP about the company’s logistics operations around the world, the response was: “It depends on where we are. In the US we have huge oil and gas production, refinery networks, logistics chains and retail networks, so our pipelines and transport systems are very different from, for example, China. In China we have several petrochemicals plants which are fed by pipeline and some products leave by pipeline, but some are trucked out, or shipped. We also supply LPG and LNG, aviation fuels, and manage retail networks there.”GAC is one player in oil and gas logistics that has diversified far and wide in Asia and Africa, from its base in Kuwait. Table 1 indicates the range of services which a 3PL like GAC can provide for its clients. Oil and gas companies can benefit financially by contracting logistics operations – in part or wholly – to 3PLs. It is often a strategic business decision which enables the company to focus on its core operations, while the 3PL handles the logistics efficiently and economically – and often much better than how the company would have done it.
This whole text has been copied from the following link and is authored by someone else as stated in the opening lines of this article.
OIL & GAS LOGISTICS
Logistics Insight Asia, 1/11/2008
Tuesday, May 5, 2009
Wind power development in Sindh By M.H Panhwar
"This article is by MH Panhwar"(credits due)
We have to speak with caution about application of windmills in Pakistan and their
economy. In their home country i.e., Netherlands, they disappeared very fast between
1920 and 1950
Hardly 7-8 per cent of those existing in 1920 have survived. These have been protected
by efforts of the Society for Preservation of Windmills, (SPW) which in turn is being
helped by the government and the National Tourist Bureau.
The windmills had ceased to be economical as compared to diesel or electric power. Most
of the windmills in the Netherlands, Denmark and other European countries were huge
monsters having diameter of 30 meters and stood on massive towers of heights of more
than 20 meters. With the highest wind velocity, at best they could develop only 20 horsepower
or 15 KW.
Though the maintenance cost is negligible, still it cannot be considered as economical as
diesel engines, which will at the most cost only 5-7 per cent of the cost of windmills for
the same power.
For some time in early 20th century, it was thought that windmills will possibly become
extinct, but the new developments for use of windmills in desert zones of Australia for
pumping water and storing it for use of sheep and high wind velocities in certain northern
Europeans countries lying between 40-60 degree latitude again revived interest in them.
In the 50's, wind power research organizations were established in most of the advanced
countries. Denmark was then leading. Now windmills are used for power development
but velocities have to be very high to make them economical. Such velocities exist in
northern Europe and also during monsoons from Bangladesh to Andra Pradesh, but not in
most tropics and sub-tropics.
High wind belt: Winds in Sindh are caused by heating of air in Rajasthan and Thar
deserts and rising of this hot air up and its replacement by cooler air blown from surface
of the Arabian Sea, moving in west-south-west to east-north-east direction to the desert.
A high wind velocity belt exists between Karachi and Keti Bunder and runs from Keti
Bunder to Mithi and from Karachi to Hyderabad and beyond to the desert. Wind velocity
data from some stations in India and Baluchistan shows that the wind velocity reduces
south and north of these belts. It also reduces as one moves inland wards i.e., eastwards.
Chore has less wind velocity than Hyderabad which has less than Karachi.
In the same way Bhuj and Raikot have less wind velocity than Duwarka. The wind
velocity at Duwarka and Verava l in Kathiawar and further to Mumbai reduces as one
moves south of Keti Bunder. Wind velocity also reduces if one moves from Karachi
along the Baluchistan coast to Soanmiani, Ormara and Pasni.
The present wind velocity data shows that maximum wind velocity occurs, at Manora
Karachi. If wind velocity is higher at any place between Karachi and Keti Bunder, the
different cannot be more than 5 per cent, which can give advantage of 15.76 per cent
higher power from the same windmill. The wind velocity at Duwarka and Veraval are
less than at Karachi, because Karachi and Keti Bunder are nearest to centre of Rajasthan
and Thar Desert.
Pattern: There are long term data for wind velocity at Manora Karachi. It appears that
wind velocity data for the whole Sind coast will be similar or about + 5 per cent. Whether
windmills will be feasible in Sindh can be determined from wind velocity patterns of
Manora throughout the year. During a year winds of different velocities blow in
kilometres per hour (kph) at Manora Karachi for the following hours:
* 12-20 kph at an average of 16 kph for 2,716 hours.
* 21-30 kph at an average of 25 kph for 1,344 hours.
* 31-40 kph or at an average of 35 kph for 282 hours.
Effects: In January 2002, Pakistan Council of Renewable Energy Technologies (PCRET)
advertised for supply of 5 KW wind mills at 39 kph wind velocity. This type of wind
velocity exists for less than 288 hours annually or an average of 46 minutes a day at
Manora.
A 5 KW windmill designed for at 39 k.p.h, will produce 3.3 kilowatts (KW) at 35 kph It
will produce 1.35 KW at 25 kph and 0.345 KW at 15 kph.
Velocity: One important factor in windmills in that power generated by the same
windmill depends upon the cube of wind velocity, i.e., if wind velocity is increased from
10 to 40 kph, power developed at 40 kms will be 64 times than at 10 kph. If the power
developed at 10 kph is 1 KW, the power developed at various wind velocities shall be as
under:
* 10 kph ---- 1 KW.
* 15 kph ---- 3.75 KW.
* 20 kph-----8KW.
* 25 kph ---- 15.25 KW.
* 30 kph ---- 27 KW.
* 35 kph ---- 42.875 KW.
* 40 kph ---- 64 KW.
This only shows the importance of wind velocity in wind power development and we are
planning windmill farms without proper investigations and planning, for wind velocities
and durations which do not exist in actual practice in Karachi or along the coast.
Though wind velocity at Karachi is 31-39 kph, it is only for 282 hours annually or about
45 minutes a day and on no day more than 2 hours. Windmills cannot be designed for this
velocity on the whole Sindh coast.
Wind velocity of 21-30 kph (average 25 kms) is available for 1,344 hours annually and
between 4-6 hours a day from mid-April to Mid-September and less than 4 hours a day in
rest of the months. The annual average utility at this wind velocity will be 15 per cent.
Wind velocity of 12 to 20 k.p.h or an average 16 k.p.h will be available for 2,716 hours
and average annual utility percentage will be 31 per cent.
One thus has to determine the range within which governor of windmill is to be adjusted
for best performance. It is also known that if governor is adjusted for 16 kph velocity, it
will produce less power at 25 kph as windmill will tilt away from wind direction at that
velocity, to expose less area directly to wind. The power of wind on a 5.5 meter diameter
windmill at 16 kpm windmill shall be 1.336 KW as shown by the following formulae:
Power KW = C x Area x (wind velocity in kph)3.
Where C the constant is, 0.000137 and power available in the air at the 16 kph will be
i.336 I(W. However only on 59.3 per cent of this power is theoretically extractable and
most of wind mills extract only 30 per cent or only 0.4 KW at this velocity. Slow speed
large diameter wind mills extract about 20 per cent. This 30 per cent is not final
efficiency as windmill generators also having an efficiency of 85-90 per cent, produce 12,
24, 48 or 120 volt direct current for charging storage batteries, a converter is needed if it
is AC generator. The loss at converts and batteries etc may further reduce the over all
efficiency, to 25 from 30 per cent produced by windmill. At the best it shall be 30 per
cent of 1.334 or O.4 kw.
The above formula also shows that power produced will be cube of wind velocity and
square of diameter.
Cost of windmills power: There are different claims for cost estimates of KWH (kilowatthour)
from windmill power, varying from Rs0.60 to Rs60. The cost will depend on wind
velocity and at low wind velocity of 20 kph will be 8 times that at 40 kph. It also depends
upon time; windmill will be operative during the year. If windmill operates only 33 per
cent of time, copper unit will be 3 times that at wind availability for 24 hours a day and
4
365 days a year.
The cost per KWH at half the designed wind velocity and annual utility for 1/3rd of time
or year, will be 24 times than claimed and planned. These factors need to be studied and
if the power generation cost is found economical, windmill farms may be established. It
is easy to get funds from aid agencies for any wasteful project but waste of these funds is
to be avoided. It is claimed that prices of oil and gas are going to increase and that will
make windmills economical. It is not realized that cost of windmills will also increase
proportionately in future.
Velocity and height: Wind velocity increases with height and it also increases if velocity
on windward side is higher. At low wind velocities, gain on leeward side reduces. Below
are some examples:
Thar: In Thar desert area, where conditions are altogether different, where water is
available at depth of 50 meters or more, and where people from all over bring cattle for
drinking water at appointed places, windmills with galvanized iron storage tanks may be
of considerable help. Annual wind velocity data for Chhor in Thar show:
* 21-30 kph for 600 hours;
* 12-20 kph for 1900 hours;
* 8-11 kph for 1400 hours.
It is only logical that windmill can pump water during first two groups of velocities and
total 2500 hours, but they will operate for 10 hours a day in May to August and only 2-3
hours during rest of months. In small towns like Chachro, where approximately, 10,000
souls reside, and the water requirement including that of their cattle is approximately
200,000 liters per day. Half a dozen slow speed multi blade mills of 10 meters diameter
may solve the town's water supply problems from May to August, but not in other
months.
Similarly, if wind mills are installed on dug wells in the desert area, each may pump
50,000 liters of water daily and may solve water problem in an area of 100 square
kilometres, depending on its human and cattle population at a given period. The total
number of windmills required in the wind belt zone of Thar desert will be 250-300, if
installed on wells and at an approximately distance of 10 Ems from each other. Large
galvanized storage tanks with overflow to carry water back to the well will be ideal
arrangement with trough, for animals, but yet winds, may not be available, when water
requirement is maximum.
The above information is based on the author's article and on "Ground Water in
Hyderabad and Khairpur Division 1964", and on results of 3-years trial on Southern
Cross windmill at Tando Jam and report published in 2nd edition of the same book in
1969. The principles of power production from wind have not changed since then. This
5
article interested Southern Cross Company of Australia and they supplied 21 foot multiblade
wind mill for trials with 20 and 30 cm diameter reciprocating pumps. This mill was
installed at Tando Jam on dug well and water table was kept constant by flowing water
back in the well.
Measurements of discharge were taken every five minute. Wind velocity data too were
recorded. It could produce 0.4 horse power at about 20 kph. Three years data were
summarized in second edition of the same book in 1969. Since then the author is in touch
with windmill manufacturers, researchers, and has collected technical publications. The
author feels that without collecting wind velocity data, duration of suitable wind
velocities and finding most suitable site, the planning windmill farm will meet failures
We have to speak with caution about application of windmills in Pakistan and their
economy. In their home country i.e., Netherlands, they disappeared very fast between
1920 and 1950
Hardly 7-8 per cent of those existing in 1920 have survived. These have been protected
by efforts of the Society for Preservation of Windmills, (SPW) which in turn is being
helped by the government and the National Tourist Bureau.
The windmills had ceased to be economical as compared to diesel or electric power. Most
of the windmills in the Netherlands, Denmark and other European countries were huge
monsters having diameter of 30 meters and stood on massive towers of heights of more
than 20 meters. With the highest wind velocity, at best they could develop only 20 horsepower
or 15 KW.
Though the maintenance cost is negligible, still it cannot be considered as economical as
diesel engines, which will at the most cost only 5-7 per cent of the cost of windmills for
the same power.
For some time in early 20th century, it was thought that windmills will possibly become
extinct, but the new developments for use of windmills in desert zones of Australia for
pumping water and storing it for use of sheep and high wind velocities in certain northern
Europeans countries lying between 40-60 degree latitude again revived interest in them.
In the 50's, wind power research organizations were established in most of the advanced
countries. Denmark was then leading. Now windmills are used for power development
but velocities have to be very high to make them economical. Such velocities exist in
northern Europe and also during monsoons from Bangladesh to Andra Pradesh, but not in
most tropics and sub-tropics.
High wind belt: Winds in Sindh are caused by heating of air in Rajasthan and Thar
deserts and rising of this hot air up and its replacement by cooler air blown from surface
of the Arabian Sea, moving in west-south-west to east-north-east direction to the desert.
A high wind velocity belt exists between Karachi and Keti Bunder and runs from Keti
Bunder to Mithi and from Karachi to Hyderabad and beyond to the desert. Wind velocity
data from some stations in India and Baluchistan shows that the wind velocity reduces
south and north of these belts. It also reduces as one moves inland wards i.e., eastwards.
Chore has less wind velocity than Hyderabad which has less than Karachi.
In the same way Bhuj and Raikot have less wind velocity than Duwarka. The wind
velocity at Duwarka and Verava l in Kathiawar and further to Mumbai reduces as one
moves south of Keti Bunder. Wind velocity also reduces if one moves from Karachi
along the Baluchistan coast to Soanmiani, Ormara and Pasni.
The present wind velocity data shows that maximum wind velocity occurs, at Manora
Karachi. If wind velocity is higher at any place between Karachi and Keti Bunder, the
different cannot be more than 5 per cent, which can give advantage of 15.76 per cent
higher power from the same windmill. The wind velocity at Duwarka and Veraval are
less than at Karachi, because Karachi and Keti Bunder are nearest to centre of Rajasthan
and Thar Desert.
Pattern: There are long term data for wind velocity at Manora Karachi. It appears that
wind velocity data for the whole Sind coast will be similar or about + 5 per cent. Whether
windmills will be feasible in Sindh can be determined from wind velocity patterns of
Manora throughout the year. During a year winds of different velocities blow in
kilometres per hour (kph) at Manora Karachi for the following hours:
* 12-20 kph at an average of 16 kph for 2,716 hours.
* 21-30 kph at an average of 25 kph for 1,344 hours.
* 31-40 kph or at an average of 35 kph for 282 hours.
Effects: In January 2002, Pakistan Council of Renewable Energy Technologies (PCRET)
advertised for supply of 5 KW wind mills at 39 kph wind velocity. This type of wind
velocity exists for less than 288 hours annually or an average of 46 minutes a day at
Manora.
A 5 KW windmill designed for at 39 k.p.h, will produce 3.3 kilowatts (KW) at 35 kph It
will produce 1.35 KW at 25 kph and 0.345 KW at 15 kph.
Velocity: One important factor in windmills in that power generated by the same
windmill depends upon the cube of wind velocity, i.e., if wind velocity is increased from
10 to 40 kph, power developed at 40 kms will be 64 times than at 10 kph. If the power
developed at 10 kph is 1 KW, the power developed at various wind velocities shall be as
under:
* 10 kph ---- 1 KW.
* 15 kph ---- 3.75 KW.
* 20 kph-----8KW.
* 25 kph ---- 15.25 KW.
* 30 kph ---- 27 KW.
* 35 kph ---- 42.875 KW.
* 40 kph ---- 64 KW.
This only shows the importance of wind velocity in wind power development and we are
planning windmill farms without proper investigations and planning, for wind velocities
and durations which do not exist in actual practice in Karachi or along the coast.
Though wind velocity at Karachi is 31-39 kph, it is only for 282 hours annually or about
45 minutes a day and on no day more than 2 hours. Windmills cannot be designed for this
velocity on the whole Sindh coast.
Wind velocity of 21-30 kph (average 25 kms) is available for 1,344 hours annually and
between 4-6 hours a day from mid-April to Mid-September and less than 4 hours a day in
rest of the months. The annual average utility at this wind velocity will be 15 per cent.
Wind velocity of 12 to 20 k.p.h or an average 16 k.p.h will be available for 2,716 hours
and average annual utility percentage will be 31 per cent.
One thus has to determine the range within which governor of windmill is to be adjusted
for best performance. It is also known that if governor is adjusted for 16 kph velocity, it
will produce less power at 25 kph as windmill will tilt away from wind direction at that
velocity, to expose less area directly to wind. The power of wind on a 5.5 meter diameter
windmill at 16 kpm windmill shall be 1.336 KW as shown by the following formulae:
Power KW = C x Area x (wind velocity in kph)3.
Where C the constant is, 0.000137 and power available in the air at the 16 kph will be
i.336 I(W. However only on 59.3 per cent of this power is theoretically extractable and
most of wind mills extract only 30 per cent or only 0.4 KW at this velocity. Slow speed
large diameter wind mills extract about 20 per cent. This 30 per cent is not final
efficiency as windmill generators also having an efficiency of 85-90 per cent, produce 12,
24, 48 or 120 volt direct current for charging storage batteries, a converter is needed if it
is AC generator. The loss at converts and batteries etc may further reduce the over all
efficiency, to 25 from 30 per cent produced by windmill. At the best it shall be 30 per
cent of 1.334 or O.4 kw.
The above formula also shows that power produced will be cube of wind velocity and
square of diameter.
Cost of windmills power: There are different claims for cost estimates of KWH (kilowatthour)
from windmill power, varying from Rs0.60 to Rs60. The cost will depend on wind
velocity and at low wind velocity of 20 kph will be 8 times that at 40 kph. It also depends
upon time; windmill will be operative during the year. If windmill operates only 33 per
cent of time, copper unit will be 3 times that at wind availability for 24 hours a day and
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365 days a year.
The cost per KWH at half the designed wind velocity and annual utility for 1/3rd of time
or year, will be 24 times than claimed and planned. These factors need to be studied and
if the power generation cost is found economical, windmill farms may be established. It
is easy to get funds from aid agencies for any wasteful project but waste of these funds is
to be avoided. It is claimed that prices of oil and gas are going to increase and that will
make windmills economical. It is not realized that cost of windmills will also increase
proportionately in future.
Velocity and height: Wind velocity increases with height and it also increases if velocity
on windward side is higher. At low wind velocities, gain on leeward side reduces. Below
are some examples:
Thar: In Thar desert area, where conditions are altogether different, where water is
available at depth of 50 meters or more, and where people from all over bring cattle for
drinking water at appointed places, windmills with galvanized iron storage tanks may be
of considerable help. Annual wind velocity data for Chhor in Thar show:
* 21-30 kph for 600 hours;
* 12-20 kph for 1900 hours;
* 8-11 kph for 1400 hours.
It is only logical that windmill can pump water during first two groups of velocities and
total 2500 hours, but they will operate for 10 hours a day in May to August and only 2-3
hours during rest of months. In small towns like Chachro, where approximately, 10,000
souls reside, and the water requirement including that of their cattle is approximately
200,000 liters per day. Half a dozen slow speed multi blade mills of 10 meters diameter
may solve the town's water supply problems from May to August, but not in other
months.
Similarly, if wind mills are installed on dug wells in the desert area, each may pump
50,000 liters of water daily and may solve water problem in an area of 100 square
kilometres, depending on its human and cattle population at a given period. The total
number of windmills required in the wind belt zone of Thar desert will be 250-300, if
installed on wells and at an approximately distance of 10 Ems from each other. Large
galvanized storage tanks with overflow to carry water back to the well will be ideal
arrangement with trough, for animals, but yet winds, may not be available, when water
requirement is maximum.
The above information is based on the author's article and on "Ground Water in
Hyderabad and Khairpur Division 1964", and on results of 3-years trial on Southern
Cross windmill at Tando Jam and report published in 2nd edition of the same book in
1969. The principles of power production from wind have not changed since then. This
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article interested Southern Cross Company of Australia and they supplied 21 foot multiblade
wind mill for trials with 20 and 30 cm diameter reciprocating pumps. This mill was
installed at Tando Jam on dug well and water table was kept constant by flowing water
back in the well.
Measurements of discharge were taken every five minute. Wind velocity data too were
recorded. It could produce 0.4 horse power at about 20 kph. Three years data were
summarized in second edition of the same book in 1969. Since then the author is in touch
with windmill manufacturers, researchers, and has collected technical publications. The
author feels that without collecting wind velocity data, duration of suitable wind
velocities and finding most suitable site, the planning windmill farm will meet failures
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