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POLDAW
Windpumps Information Sheet |
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Designed
and developed by Neale Consulting Engineers Ltd. (NCEL), UK, Poldaw Windpumps
are intended principally for applications in developing countries. They are a truly “appropriate technology”
for rural water supply in many situations. |
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The
Poldaw Windpumps are a range of medium sized low cost machines. The designers
have extensive experience of appropriate technology machinery design,
refining and finalising the “Intermediate Technology Development Group” (a UK
charity) design of its “IT” windpump for the developing world during the
1980’s. They have been involved with the design and production of windpumps
and other machinery for use in developing countries since 1982. From their
experience they have identified the importance of certain design criteria
which are applicable to windpumps anywhere in the world:- |
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·
Robustness
and reliability (design life-span of at least 20 years) |
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·
Practical
and cost-effective manufacture |
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·
Easy, safe
installation and maintenance |
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Start-up in
low wind speed (3 m/s or less) |
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·
Survival in
high winds (50 m/s, 180 km/h) |
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Adequate
pumping capacity |
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·
Low speed
operation for smoothness and reliability |
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The
Poldaw designs meet these criteria, and at the same time achieve the lowest
cost possible without compromising robustness and reliability. |
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Benefits of Poldaw Windpumps:- Poldaw
Windpumps were designed and developed using modern engineering design know-how,
achieving:
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Ultra-low
operation and maintenance costs: maintenance is a simple annual procedure |
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·
Proven,
reliable, robust, sustainable technology |
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·
Manufactured
locally using readily available materials, to benefit the local economy |
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·
Value for
money, costs competitive with other pumping methods and lower than most other
windpumps |
How
much water do the Poldaws produce? The
performance of the Poldaw Windpumps depend on pumping head (i.e. total
lift required) and windspeeds. The two most popular models are the 3.5m
machine (the diameter of the rotor is 3.5 metres) and the 5m machine.
For a moderate pumping head of 20m, in a medium wind speed of 4m/s, outputs
are:
There are also smaller models, 2.2m and 1.8m, with correspondingly smaller outputs. |
| The 3.5
metre machine can pump from depths of up to 90m, whilst the 5 metre machine
can pump from 140m, now extended to 200m max by means of a spring
counterbalance system. Further details of pumping performance can
be found in
Technical Data |
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Are there siting or wind condition constraints? The Poldaw can start up under load in the
lightest of breezes and operates in wind speeds as low as 3 metres per second
(approx. 7 mph). A simple test with an anemometer will confirm local wind
speed conditions. |
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A
range of tower heights is available, selected to suit local topography and
wind conditions, for example a sheltered site may require a tall tower. If
there is doubt about the suitability of a site for a windpump, Poldaw and/or
its local licensees will advise. |
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Cost effectiveness of the Poldaw Windpump:- The Poldaw Windpumps costs 30% less to
manufacture than other similarly sized windpumps and, being made with local
materials and labour, have no import duties. |
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The
initial purchase cost of a community water supply system using a Poldaw
Windpump varies from country to country, but generally compares favourably
with other powered pumping systems. |
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Running
costs are negligible due to no fuel and minimal straightforward maintenance. |
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Who manufactures Poldaw Windpumps?
The Poldaw is a modern appropriate technology windpump design, which
can be made easily in any country using readily available materials with
basic engineering tools and equipment. |
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The
preferred approach is to licence the design to local manufacturers who make,
sell, install and maintain the windpumps as required. As part of the licence
agreement, Neale Consulting Engineers provide on-site training, transfer of
know-how and ongoing technical support to the manufacturer. |
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Poldaw
Windpumps are currently manufactured in the UK and in a number of countries
in Africa and Asia. Click here for list. |
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Easy maintenance:- Poldaw Windpumps have been
designed to need very little maintenance. All that is required is the
greasing of bearings once a year, with a general inspection of other
components. The principal wearing parts of the whole system are the leather
sealing washers in the pump piston, which are replaced on average every 2 to
3 years. |
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Routine
maintenance and pump washer replacement can easily be carried out with the
tower standing. To simplify installation, and for any major borehole or windpump
maintenance, the tower has been designed to hinge on two of its three feet so
that the whole machine can be laid down by use of a winch. |
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Local
mechanics can be trained in one to two days to carry out these procedures or
the local manufacturer can provide support under an ongoing contract. The
skill level required is much less than for diesel engine maintenance and
attention is only needed once per year. |
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What happens when the wind doesn’t blow? Windpumps are suitable for any location
with an average wind speed of 2.5 m/s or more and with no prolonged windless
periods. |
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In
such locations, on most days there is sufficient wind for the windpump to
operate for at least part of the day. However, to provide against windless
days, the Poldaw Windpump is usually installed with a water tank or
reservoir. Generally a tank with three days of water supply is adequate. |
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What happens when there is a storm?
The Poldaw Windpump is designed, through the use of a hinged tail
vane, to turn (or “furl”) automatically to minimise the area facing into the
wind. By means of this mechanism it will withstand storms of over 180
kilometres per hour. |
Poldaw Windpumps are ideal for a wide range of community,
agricultural and industrial applications, for example;
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·
Villages |
·
Nomadic
peoples |
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Schools |
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Nature/wildlife
reserves |
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Clinics |
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Farms
(irrigation) |
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·
Farms (livestock)
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·
Waste-water
treatment |
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·
Small scale
industry |
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Aeration |
Poldaw Windpumps can pump from:
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· Open (dug) wells |
· Rivers |
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· Boreholes (tubewells) |
· Lakes |
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· Springs |
· Marshes (drainage) |
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· Dams |
· Sea (salt production) |
Pumping systems:-
Poldaw Windpumps not only lift water to a
surface tank adjacent to the source but also, with appropriate plumbing, can
pump water great distances and to substantial heights. Poldaw Windpumps are
used to pump water to:
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· Tanks on raised stands or
nearby hills |
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· Remote tanks or
reservoirs (distances of over 1 km and heights of 50 m) |
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· Pressurised drip
irrigation systems |
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· Water distribution systems
(usually with header tank) |
POLDAW INSTALLATIONS IN AFRICA AND ASIA:- Poldaw
Windpumps have been installed in many different situations in developing countries
in Africa and Asia, ranging from village communities, schools, clinics, farms
through to small industrial sites. The following examples give a flavour of the
types of situations where Poldaw Windpumps have been used:-
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· Munyikwa Secondary School, Gutu District, Zimbabwe. A Poldaw
3.5m Windpump pumps water to a 10,000 litre tank from where it supplies
twenty stand pipes for the school’s 500 pupils and the surrounding community.
Total pumping head is 20m. |
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· Chitora Rural Clinic, Near Mutare, Zimbabwe. A Poldaw 3.5m Windpump
supplies an elevated tank through a 100m pipeline. Total pumping head is 15m.
About 700 people benefit from the water supply. The project was funded by the
E.U. Microprojects Programme. |
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· Chiwero Farm, 80km West of Harare, Zimbabwe. A 3.5m Poldaw Windpump feeds a 10,000
litre tank which supplies four standpipes via 100m of piping. The total
pumping head is 14m and about 500 people benefit from the water supply. This
is a Communal Farms project funded by the Methodist Church. |
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· Solapur, India. A farmer is using a
Poldaw Windpump for farming and domestic purposes, irrigating vegetable and
fruit crops. He uses a 3.5m machine with a total pumping head of 35m (120
feet). The windpump was purchased by the farmer. |
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· Baluchistan, Pakistan. A pilot project for
drought alleviation has been carried out in over 20 rural villages. Poldaw 3.5m windpumps are used on hand dug
wells with depths varying from 15 to 35 m (50 to 120 feet). The windpumps provide domestic supply for
the villagers, and drinking water for livestock. Surplus water is used for growing of vegetables etc. Funding has been provided by the
Baluchistan regional government. |
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· Zambia. Various Poldaw windpumps,
3.5m and 5.0m models, are being used in combination with drip-irrigation
schemes to grow a variety of crops. |
Applications in Western Countries: Poldaw Windpumps are also being
used in the UK. The benefits and uses of windpumps are different in Western
countries with widespread rural mains water and electricity distribution.
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· Cost of mains water: The
use of high-quality mains drinking water is an unnecessary expense for irrigation,
watering animals, wetland maintenance or industrial purposes. Windpumps can
be used to provide cheap non-drinking water. |
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· Remote locations without
mains: If a borehole is more than 1 - 2 km from a mains electricity supply a
windpump is often the most economical solution, due to the high cost of
installing a mains supply. |
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· Environmentally sound
solutions: Poldaw Windpumps are being used for nature reserves, wetland
rehabilitation schemes and for waste-management where ‘environmentally
friendly’ solutions are required. |
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· Low running costs: A
windpump can be used in remote locations and will operate continuously
without attendance. |
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· Leachate pumping: Poldaw Windpumps
are being used to pump leachate (toxic liquids) from capped landfill sites.
Such sites often have methane present, so the purely mechanical operation of
the windpump avoids explosion hazards. |
WHERE YOU CAN VIEW POLDAW WINDPUMPS: A Poldaw 3.5m Windpump is on permanent display at the Centre for Alternative Technology (C.A.T), Machynlleth, Powys, SY20 9AZ , UK , (tel +44 (0)1654 705950) and is available for public viewing. See http://www.cat.org.uk
Other Poldaw windpumps in service in various countries
can be viewed by arrangement with Neale Consulting Engineers, or with the local
manufacturer.
(List updated January2008)
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ZIMBABWE: |
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Annevor
Systems |
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PO
Box BW1299, Borrowdale, Harare, Zimbabwe |
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Trevor
McEnery |
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Tel
002634 308495, fax/tel 002634 882718 |
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email:
annevor@utande.co.zw |
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UK: |
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G
B Windpumps |
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Willowbrook,
The Street, Kilmington, Axminster, Devon EX13 7SH, UK |
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Chris Thorne |
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Tel +44 (0) 1297 631672, mob 07870 114072 |
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email: sales@windpumps.co.uk |
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website: www.windpumps.co.uk |
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TURKEY: |
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MANES Demir Urunleri Sanayi ve Ticaret Ltd. (formerly Genba Ltd.) |
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Istiklal Mahallesi 40 Sokak No:89 Z/2-3, Ulucak Kemalpasa,
Izmir, TURKEY |
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Cengiz
Oguzer |
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Tel. +90 232 877 20 67-68, Fax +90 232 877 20 69 |
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email: cengiz_oguzer@genba.com.tr |
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ETHIOPIA: |
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GEM Engineering General Trading plc |
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Debre Ziet Road, Near to Kadisco Building PO Box 122814, Addis Ababa, Ethiopia |
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TEL:- 00251-114401197 FAX:- 00251-114404095 |
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Mr Girma Eshetu |
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email: gemeng@ethionet.et |
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PAKISTAN: |
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Agrotool (Pvt) Ltd. |
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Sohana Research Farm, Gulshan-e-Iqbal, Block 1, Karachi, Pakistan |
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Mahmood Futehally |
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Tel: 00 92 21 4994531 (office). Fax: 00 92 21 2417836 |
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email nfit@cyber.net.pk |
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BOLIVIA:
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Terry Waller, c/o: World Concern |
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Casilla 3681, Santa Cruz, Bolivia |
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Tel. + 591 3 965 6912. Cell + 591 7 101 8858 |
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email: terry@southlandbaptist.org |
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website: www.geocities.com/h2oclubs/ |
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NIGERIA: |
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Alkatbu Technologies Ltd. : Dr. Alka |
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No 18 Abu Bakar Tafawea, Balewa Road, Bauchi, Nigeria |
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Tel: 0023477 542268/ 541164. Fax:0023477 543102 |
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email alkagroup@yahoo.com or ecclesuk@aol.com |
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GHANA: |
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Mr
B M Oppong |
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Village Infrastructure Project (VIP), The Ministry of Food and Agriculture. |
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PO Box CT 3742, Cantonments, Accra, Ghana |
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Tel 00233 21 770246 . cellphone 0244 383 133 fax: 00233 21 770247 |
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email: Mr. B.M. Oppong, c/o: jcrbekoe@yahoo.co.uk |
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ZAMBIA: |
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Songhor Agricultural Ltd. |
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P.O.Box 11, Fringilla, Zambia |
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Roger Mase |
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Tel +260 1 212117 cell 096 262 298 |
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email: mase@zamnet.zm or allisongeorge@gmail.com |
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AFGHANISTAN: |
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Qaderdan Rural Technology Development Work Shop (QRTDW) |
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Street no. 2, Karte-e-Char, Kabul, AFGHANISTAN |
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Mr Habib Qaderdan |
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email: qaderdan_rtdw@yahoo.com |
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website: http://www.qrtdw.com/ |
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Tel. (0093) 70287029, 79337463, 79401597 |
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SOUTH AFRICA: |
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Villiers Aqua Engineering |
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PO Box 98, 7 Cornelis Street, Villiers, Republic of South Africa 9840 |
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Friamie Vorster |
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tel 0027 (0) 58 821 0765. cell 0027 (0) 72 236 6845, Fax 0027 (058) 821 0765 |
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email: villiersaqua@lantic.net |
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website: www.poldawwindpumps.co.za/ |
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ECUADOR: |
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Hofloye Ltd: Marco A Hof |
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Appartemento 4B, Condamine N17-46 y Oleas, Vicentina, Quito, Ecuador. |
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Marco Hof |
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tel 0059323228480, cellphone: 00593 93676883 |
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email: max_hof2003@yahoo.co.uk |
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Technical Details: Design for low cost and
high reliability:-The Poldaw Windpump has a very simple but elegant design.
Most successful small windpumps with a deep well capability use a speed
reduction gearbox to avoid dynamic problems in the pump and pump rods.
However, gearboxes are expensive, difficult to manufacture, and require good
lubrication and therefore high maintenance. The Poldaw transmission uses a
simple crank and rocker arrangement, with a specially developed rotor which
develops high torque at low speed. The elimination of the gearbox thus
reduces the cost and improves reliability. |
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Lubrication only once a year:
For
the continuously moving joints, self-aligning ball bearing units are used,
which are universally available, very reliable and only require greasing
about once a year. Other bearings and pivots which only move intermittently,
are made from polymeric materials or hardwood. |
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Pumps and pipelines: The pump itself consists
of a simple cylinder incorporating a non-return valve at the bottom and
another in the piston. The pumps vary in diameter, depending on the required
pumping head. For pumping a long distance to a remote tank, an air chamber
may be incorporated. This evens out the pulsing water flow from the pump and
thus reduces the stresses on the windpump mechanism. |
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Automatic Storm Protection: Poldaw Windpumps protect
themselves from damage in very strong winds, by turning the rotor edge-on to
the wind. This takes place automatically in wind speeds of over 50 km/h, and
enables the windpump to withstand storms of 180 km/h (50 m/s). When the wind
drops again the rotor resumes its normal position facing the wind. |
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PUMPING PERFORMANCE The output capacities for
the range of possible Poldaw Windpump applications can be seen in the
following tables. |
Poldaw 5.0m Windpump (Approximate outputs in litres per 24 hours)
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TOTAL PUMPING HEAD |
Light Wind – 3 m/s |
Medium Wind– 4 m/s |
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Feet |
(Metres) |
Litres/day |
Litres/day |
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15 |
5 |
85,000 |
180,000 |
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30 |
10 |
41,000 |
90,000 |
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50 |
15 |
27,000 |
60,000 |
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80 |
25 |
16,000 |
39,000 |
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100 |
30 |
14,000 |
32,000 |
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150 |
45 |
9,000 |
22,000 |
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200 |
60 |
7,000 |
16,000 |
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250 |
75* |
5,500* |
13,000* |
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300 |
90* |
4,500* |
11,000* |
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400 |
120* |
3,400* |
8,000* |
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500 |
150* |
2,700* |
6,000* |
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600 |
180* |
2,200* |
5,000* |
* Note – to achieve these outputs on heads of 75m+, spring counterbalancing is required.
Poldaw 3.5m Windpump (Approximate outputs in litres per 24 hours)
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TOTAL PUMPING HEAD |
Light Wind – 3 m/s |
Medium Wind– 4 m/s |
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Feet |
(Metres) |
Litres/day |
Litres/day |
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15 |
5 |
45,000 |
90,000 |
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30 |
10 |
22,000 |
45,000 |
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50 |
15 |
15,000 |
29,000 |
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80 |
25 |
9,000 |
16,000 |
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100 |
30 |
7,000 |
13,000 |
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150 |
45 |
4,700 |
8,000 |
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200 |
60 |
3,000 |
5,500 |
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250 |
75 |
2,200 |
4,000 |
Poldaw 2.2m Windpump (Approximate outputs in litres per 24 hours)
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TOTAL PUMPING HEAD |
Light Wind – 3 m/s |
Medium Wind– 4 m/s |
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Feet |
(Metres) |
Litres/day |
Litres/day |
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15 |
5 |
15,000 |
32,000 |
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30 |
10 |
7,000 |
15,000 |
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50 |
15 |
5,000 |
9,000 |
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65 |
20 |
3,500 |
6,700 |
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80 |
25 |
2,500 |
5,000 |
Poldaw 1.8m Windpump (Approximate outputs in litres per 24 hours)
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TOTAL PUMPING HEAD |
Light Wind – 3 m/s |
Medium Wind– 4 m/s |
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Feet |
(Metres) |
Litres/day |
Litres/day |
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15 |
5 |
10,000 |
24,000 |
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30 |
10 |
5,000 |
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