Good solar water pumping companies in Mali?
This is an update on "Cost and reliability of solar pumps in Mali?"
I am drilling some new wells and rehabilitating / replacing a number of PV powered water pumps in northern Mali (both drinking water and irrigation, but all are submersible pumps in boreholes). Many systems in the area are no longer working, and I even see relatively new (<1 year) systems both Grundfos and Lorentz that have failed. Unfortunately, I do not yet know the reasons for this failure trend, as the reports I receive from local consultants do not contain any diagnostics on the systems or even photos of failed parts.
Going forward, what are recommended installation companies for 5-15m3/hr solar powered pumps? And which companies do the best inspection and appraisal, both for new wells and for existing?
Your question raises many questions.
I have worked in Mali but my experience may not be relevant
It may be appropriate to find out the reason for the problems with the existing pumps before drilling new boreholes or ordering new pumps
Which part of northern Mali is your area?
Are you in the bush at the moment?
Have you been to the sites where the pumps have 'failed'?
If you have been to the boreholes, do you know the borehole designs, construction details, water levels and pump intake depths?
There are many reasons why a pump has been described as 'failed'.
A common technical reason for a pump to fail is that someone misguided has decided to put the pump at the bottom of the borehole, rather inside the 'pump chamber casing' and carrying out a pumping test to determine the drawdown at a particular yield. Then using this information to choose the appropriate depth to set the final production pump.
Relatively young, high quality pumps (such as Grundfos) usually don't fail in a short period of time, if they have been put in the right position in a properly constructed borehole and operated properly.
Your assessment of the pump problem and the boreholes may give you good information that enables you to appropriately modify your borehole designs before you start drilling new holes.
I'm an undergraduate aero-mechanical engineering student who lived in Malawi for 4 months last summer. I had issues with new (1-2 year old?) Grundfos borehole pump there but I was able to ultimately successfully resolve them with easy fixes; the pump is still presently operational.
Their local reseller wasn't that helpful and instead quoted us for a whole new pump assembly (extortionate and shipping from South Africa). We got it back up and running with a clean and some sunflower oil.
The pump we had was a highly sealed unit. The electronics and stator were one fully sealed stainless steel assembly, welded closed. The mechanical half was screwed on to this and was a shaft with permanent magnets and the pumping rotor (helical core). The mechanical half (top) was available more cheaply, separately from the electronics (bottom half).
The pump was made to fit in to a standard borehole, the type local contractors were familiar with drilling. Of course, the flowrate that the solar pump was capable of was an order of magnitude higher than manual pumps. This gave rise to some hydrogeologic issues - namely that the velocity of groundwater flow to this source was likely several orders of magnitude above that of natural groundwater flow,probably causing turbulent flow that was likely responsible for the pump becoming absolutely covered in wet, sandy mud/silt.
We filled up a tall tank of water and ran the pump for a while off some batteries, monitoring its performance. We really had to clean the internals of the mechanical parts though, some of the bearing surfaces were covered in this bizarre dry dust (dried mud?) that was somehow really clogging the whole thing up. The pump would start up for an instant but then decide not to bother within about 1s.
The grundfos pump had a water level sensor - believe it to be a pressure transducer - that required to be immersed water at some depth for around 5minutes before the pump wanted to start up. (When I initially brought the pump to them, the guys at the local Grundfos branch tried unsuccessfully to test run it by placing this sensor is a shallow plate of water....)
The pump used proprietary Grundfos "motor fluid" called SML-3, this floods the area between the rotor and stator in the top of the electrical half. Our pump didn't have any inside (very strange). This was not even available in South Africa, let alone Malawi. After some research, I believe the fluid to be antibacterial liquid with some antifreeze (and of course non-toxic). We substituted with sunflower cooking oil. Still working well. The pump was rated for 1.5kW but only connected to 350W of solar so we were pretty happy with the heat transfer there. We somewhat suspected the pump also had an oil sensor of some kind, which could've been another explanation for the aforementioned brief successful start up before it decided to turn off. It also had thermal protection which ... (more)
I am unable to find the reasons for failure often, it is not common (in my limited experience) for Malian consultants to determine the cause of failure or even the precise part that has failed. I struggle with this on all my projects, including vertical construction (inspection and supervision) and PV systems too. I have developed a new inspection sheet format so that they answer what I need to know, instead of me sifting through a 30-page document for 2-3 relevant sections necessary for project progress.
I am working in areas of Gao, Timbuktu, and Douentza, specifically N'kahaka, Kaji, Gouma Rharous, Gossi, Andongo, Niafunke, Araoune. These are conflict areas so I am unable to travel there my self to do a full diagnostic + yield test. Some southern Malians (i.e. Bambara) are also reluctant, so we are limited in our consultant list sometimes.
I am in Bamako today but I travel tomorrow for a week, Douentza and Timbuktu.
Typically I am getting what may be reliable dynamic water level and maximum yield, they are elaborate and done by a hydrologist (or at least with a spreadsheet they got from a hydrologist), but sometimes I wonder if the consultants have even been to the site at all... It is very common for consultant to write 'replace well head with same diameter,' without providing a photo, telling me the diameter, the existing material, the components, etc. I am burning through consultants, not happy with any engineering reports or CAD from 5+ firms so far, if you have recommendations please please provide.
Pumps are often specified (by the consultant in their recommendations) at about 25-50m depth, even on deeper holes (80-100m), so I assume that pump depth is not the problem. Though, it may be a reason for failure in previous installations, where again the consultant does not tell me the reason for the failure.
Unfortunately we (AECOM) installed two Grundfos pumps recently and they failed <6 months. Believe me I have tried to find the reason but I have not uncovered it yet (and I have $2m work right now with one assistant and sites are almost all remote and difficult to access).
Note that we are only drilling holes on a few projects, most of the systems are replacement of existing.
Recommended installer by Grundfos: Mr. Sow @ AGEDIEX +223 76 30 58 14 firstname.lastname@example.org
Recommended installer by Lorentz: Mouctar Doucoure @ Sonikara Solar (+223) 76 30 58 14 or (+223) 66 69 72 73 email@example.com
Other Companies: Ousmane Konate @ Yandalux (+223) 20 21 91 42 firstname.lastname@example.org
Pierre Maldame @ PPI (+223) 71 44 67 10 email@example.com
Modibo Tamboura @ SEEBA (+223) 76 45 13 77 firstname.lastname@example.org
Moussa Coulibaly @ Aircom
(+223) 66 78 21 04 email@example.com
Chris, I used to work in the Adrar des Iforas. I know your area as I have travelled through all your towns, but I have no useful experience of drilling in these areas.
I picked up that you refer to work by 'hydrologists'. There is often confusion about this professional name, particularly in franco-phone countries. If you have not done so, could I suggest that you clarify whether you are engaging, or reading the reports of, hydrogeologists (trained with groundwater skills and drilling) or hydrologists (trained in surface water, rainfall run-off relationships, channel flow)?
Sometimes, local hydrologists, civil engineers and geophysicists, by necessity, pass themselves off as hydrogeologists, when they do not have the skills for your work.
From what you say about your daunting project, I would recommend that you engage an experienced field hydrogeologist.
You say that you work for AECOM. AECOM merged with URS. URS had some excellent hydrogeologists with over 30 years experience.
The hydrogeologist(s) have to be able to get to the sites to do their work. They can't do it at a distance from the sites.
They need to be on the sites while pumps are lifted and inspected or stripped down, the borehole is plumbed, airlift surged and airlift pumped, then all the information obtained is assessed by them, and if justified, and a new pump is installed.
The hydrogeologist should be able to determine the condition and value of an an existing borehole if they are on site and free to use their skills and experience. They should be able to determine a correct and safe position for the new pump.
The hydrogeologist also should be at the back of the rig, right next to the driller, whilst all new drilling, or borehole work-overs, are carried out; so that they can make decisions with the driller on how to modify the borehole design, during the construction in the light of the findings, as they arise.
If you cannot get an appropriately skilled and experienced 'bush hydrogeologist' on site full-time, then I suggest that you use this barrier to defer the project until access by the right professional becomes possible.
I am sure AECOM wants to get the project done properly, but it does not look possible if you are trying to do it remotely through unproven third parties, who may not be wildly enthusiastic about being there in the first place.
I apologise if it seems that I am "teaching a grandmother to suck eggs".
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