The Rope Wind Pump

THE ROPE WIND PUMP

A new, low cost technology for water-pumping with wind energy.

In Nicaragua like many other countries, the long dry periods and irregular rains limit rural production.

With irrigation it is possible to regulate and raise that production. However, technology like certain irrigation systems, or even a diesel pump, is often too complicated or expensive for the small and medium scale farmer.

In Nicaragua, there have been developments in low cost water pumping technology in the last 15 years.

The main one is a hand-pump called Bomba de Mecate, which is an improved rope and washer pump. It is based on a different principle from traditional piston pumps such as the Dempster or Indian Mark 2.

The rope pump has a rotating movement, is made of local standard materials, has a cost of only 50 to 80 US$, and is simple so that the user can maintain it.

It is now so popular that more than 15,000 pumps are already installed in Nicaragua and neighboring countries.

The pump can lift water from deep wells, up to 80m, but after 40m it becomes too difficult for one man to move it. However the basic rope pump can be combined with other driving mechanisms such as bicycle power or animal traction.

A newer development is the Aerobomba de Mecate or Rope Wind-pump, which combines this hand-pump with a light and modern windmill.

This simple and low-cost technology can help to improve rural production by irrigating fodder crops, vegetables, and fruit trees.

It can also be used for fishponds, cattle watering, or domestic purposes, where it eases the work of women and children who normally take care of the water supply. It pumps water without the hard work of a person, but also without the cost of diesel fuel.

The combination of the rope pump with a windmill means that compared to other wind-pumps, the Rope Wind-pump has many interesting features, for example

- It connects the rotating movement of the rotor directly to the rotating movement of the pump. In this way it avoids the dynamic forces which are often a problem in wind-pumps with a piston like the CWD 5000.

-It has an automatic and simple safety mechanism based on a modern Dutch design, which has proven to work very well. Low cost wind-pumps like Mira Mar from Peru or the Cretan model do not have this safety system which makes them vulnerable in strong winds.

-The rotor of the Rope Wind-pump has a low solidity and therefore, the head and tower construction can be very light. For instance its total weight is only 25 % of that of an American Multiblade.

-The starting wind speed of the Rope Wind pump is as low as 4 meters per second.

-The installation takes around 5 hours and can be done by two technicians as long as four other people help them with erecting the tower. During installation the user of the wind-pump is instructed in the maintenance, which can be done with only two spanners and an oilcan.

-The Rope Wind-pump does not have corrosive pump parts and uses PVC pipes, which are very light. Other wind-pumps use piston pumps, which are complicated and often give problems with maintenance because of corrosion, and the heavy pump pipes.

-The Rope Wind pump is made of local and standard material and can be produced in a workshop with basic machinery. For example a lathe is not needed.

- It can easily be transported and the whole wind-pump, including the prefabricated foundations, can fit onto a pick-up truck.

-The foundations do not need extra cement as the same soil is used as anchor weight.

-It uses wooden bushes on the rotor and pump shaft, which have proven to be durable, cheap and even easier to maintain than ball bearings.

The most common Rope Wind-pump is the 270 model, which is limited in its ability to turn around in all wind directions. A newer model does not have this limitation although daily attention is needed to avoid the ropes wearing against each other.

The investment costs of the Rope Wind-pump are as low as 450 US$ for the small model with a rotor of 2.5 meters. The biggest model with a rotor of 3.6 meters costs 800 US$. Maintenance consists of daily control, adjusting the ropes and oiling the bearings. The cost of maintenance depends on the use but varies from 20 to 60 US$ a year.

An evaluation of the Rope Wind-pump has shown that it pumps water at half the cost of either a diesel electric pump or an imported wind-pump.

In the last 5 years more than 100 systems have been installed in Nicaragua and the technology is now spreading out to other countries in Latin America.

Experience proves that the Rope Wind-pump has many advantages compared to other wind-pumps developed in the past.

It needs regular attention, but it is a simple and modern technology, which can be locally produced, has a low cost, and is easy to maintain.

For more information please contact: Webpage@gamos.org

If you have reached this page via a search engine and are not using the framed navigator, please click here.
If you cannot support frames, click here for an older non-frames version of the site