For over a hundred years, conventional windmills have been built to draw water from wells. Mills built to the old design, however, weigh over half a tonne; to function, they require strong winds. Unfortunately, tropical countries lack sustained winds; however, there are powerful storms during very short periods.
In recent years, many people have tried to design newer, simpler and more economical mills. Lacking regular strong winds, one made of metal drums, for example, only works a few days a year, and eight steel rods are not able to hold it in place during a storm. Scientists and technicians from the Gaviotas ecovillage resolved to create a new windmill concept: a tropical windmill.
Over nine years, they built 58 different mills. Each contributed in part to the creation of the Dual-Effect Gaviotas MV2E Windmill. Here, for example, was first tested the high-thrust rotor drive now used in all MV2E Gaviotas mills. As many as 800 Model 80 and 1,300 model 81 mills are installed throughout Colombia. They have also been exported to other nations of Asia, Africa and Latin America. In the Gaviotas manufacturing facility in the Vichada Department of Colombia, technicians weekly build hundreds of double-effect windmills, created with the particular characteristics of the Tropics in mind.
Advantages of the Gaviotas 'MV2E' over traditional mills are:
- it has a weight 10 times lower;
- its purchase price is considerably lower;
- it needs three times less wind;
- it requires no braking during storms; and
- by following directions, its installation is a simple do-it-yourself project.
An example[edit | edit source]
Abraham Beltran and Gladis breed chickens and cattle on the shore of Caño Zapata in Alto Vichada, 7 km from their nearest neighbours. They think of them as nearby, though, because Abraham is a regional cycling champion.
So as not to have to rely on a piped-in supply, they used profits from their henhouse to drill a 75-metre-deep well intended to extract clean groundwater both for the house and for the garden, as well as troughs for the chickens and cattle. They then saved the money needed to buy the windmill to operate the water pump.
Typical design[edit | edit source]
In hand-dug wells (90 cm to 1.1 m) the best support for the mill is a rim of 0.7 m to 2 m in height. Formed like a pipe with three crenellations each about 20 cm deep, the rim should be approximately 1.25 m in exterior diameter and ca. 1 in interior diameter; thus the rim will be a little over 12 cm thick. Where possible, there should be a lid to prevent animals and children from falling into the well. A cover will also help to block warm sunlight, which could increase the rate of evaporation loss.
References[edit | edit source]
- Jorge Zapp Glauser, Un Molino de Viento Tropical Gaviotas Doble Efecto, Manual de Instalación, Manejo y Mantenimiento del Molino de Viento MV2E, Centro las Gaviotas, Orinoquia Colombiana, Paseo Bolívar No. 20-90, Bogotá, Colombia, 5th ed., pp. 6–10, 12. Accessed 6 September 2012.
- Paolo Lugari, A new Renaissance in the tropics, Fundación Centro Experimental Las Gaviotas, p. 11. Accessed 25 September 2012.
Availability[edit | edit source]
- Based on a public-domain Spanish-language article, available online as a low-quality scan: PDF, 28 MB