Windmills for pumping water
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CTA. 2008. Windmills for pumping water. Rural Radio Resource Pack 08/3. Wageningen, The Netherlands: CTA.
Permanent link to cite or share this item: http://hdl.handle.net/10568/57402
A new design of windmill under trial in Zimbabwe
Windmills for pumping water Cue: Using wind power to pump water from the ground is something that has never really taken off. The high cost of building and maintaining windmill pumps has put people off. The other problem is that you may also need to build a large water storage tank so that you will have enough water to use even on days when there is no wind blowing. But a lot of wind enthusiasts always believed windmills can be cheaper than using a diesel or petrol powered pump. Now, two engineers in Zimbabwe are trialling a new design of windmill pump, which they believe could be an answer to rural water supply. Busani Bafana reports: IN: ?Windmills, a common feature in farms?? OUT: ? try to work towards a branding.? DUR?N: 5?47? BACK ANNOUNCEMENT: William Goriwondo and Nicholas Tayisepi from the University of Science and Technology in Bulawayo, Zimbabwe, talking with Busani Bafana. The interview comes from a resource pack produced by CTA. Transcript Bafana Windmills, a common feature in farms across Zimbabwe, especially before independence, are making a comeback as an icon of ingenuity for farmers in harnessing wind energy to help operations on the farm. A team of researchers at the National University of Science and Technology in Bulawayo, Zimbabwe, have developed a cost-effective windmill pump system which they have just tested in the field. In today?s programme, research team members and engineers, William Goriwondo and Nicholas Tayisepi, share with our listeners how the windmill pump system works and its benefits for farmers. William, I?ll start straight away with you. Some of our listeners may not be familiar with the windmill powered pump. How does the pump system work? Goriwondo The pump system is a submersible pump which is put in the borehole and then the windmill would actually be harnessing the wind energy, convert it into the sprocketing motion that will then pump the water. Bafana Is the water then pumped into a storage tank from where the water is drawn for use? Goriwondo Yes. There is an option of putting a storage tank. The tank would actually be raised above ground so that we have got the pressure when we need to use the water. But otherwise you can have the windmill pump pumping directly to your source of use. But in that case there would be excessive water which may be lost. Bafana We are talking about a windmill pump system. Does it only work when it is windy? Goriwondo It uses wind energy but our design would actually improve on it to harness the smallest amount of wind flow which is there. Bafana Does the speed of the wind then determine the amount of water that can be pumped at certain times of the day? Goriwondo Yes. The speed of the wind determines. As the wheel moves faster the pump will also be pumping faster. But when it is completely windy it doesn?t turn. Bafana How does this pump that you developed provide a solution to the water needs of the community, particularly farmers? Goriwondo In most farms around here there is no electricity. So this pump would actually be using the wind energy and it would provide for the energy that is required to pump water for domestic use, as well as for animals and other farming activities. Bafana I would now like to actually turn to Nicholas to actually describe to us about the capacity of this pump. For example, on average how much water can you pump over on a typical day or during the typical week? Tayisepi On average we are looking at up to 60,000 litres of water per day. Working on a 40 per cent effective wind day period. Otherwise it can generate a bit more than this, provided we have sufficient storage capacities for harnessing the water for the period it is pumped. Bafana Looking at the community where you actually installed this pump, how can you use that water? Tayisepi They have a cooperative garden. That water is meant to provide the horticultural activities watering needs. Bafana Can this pump system be used for any other on-farm activities? Tayisepi Yes. From the household use to livestock, to irrigation, to market gardening, you name it. Most farming activities require water; that gadget can be used for that. Bafana What kind of challenges did you meet in designing the wind pump? Tayisepi In terms of the challenges we are looking at the costs associated with the installation of the wind pump. Like this design that we have at the moment was going for US$13,000, that?s for the whole process, labour and materials included. And this is a product that can be used at community level. But then also one of the challenges we have at the moment is the aspect of the material costs, due to the inflation we are experiencing. Bafana You have already mentioned that it cost you something in the region of US$13,000 to come up with the design and to install it. I would then want to find out, how do you maintain this pump? Tayisepi In our process we included community cadres out there, that is community members who will remain and are taught to maintain those gadgets. That way we, I think we believe it will ensure the windmills will always be working because they know how to maintain the basic parts. Bafana Does this pump then meet local conditions? Tayisepi Yes it does. The countryside of Zimbabwe?s communal lands mainly is quite windy for a good part of the year. Like William had indicated, the design we came up with uses very low energy from wind. So you find with the average wind speed we experience in Zimbabwe, it is said that it can pump water perennially. Bafana What are the future prospects for commercialising this windmill pump system? Tayisepi There is quite a future in it as long as we keep on improving on the design and especially the storage capacity. Like we had indicated, this windmill can pump up to 60,000 litres a day. But in terms of the storage arrangement we have at the moment, most of it will not be stored. So if we improve on the storage side of the process we are going to have quite an enhanced capacity as well. Bafana I thought I could as well ask you, does your pump system have a name? Tayisepi That?s ok. It is called a windmill, that?s all. We will brand that shortly, now that you have suggested it. That sounds very interesting, we will definitely try to work towards a branding. End of track