By Mark Bryant and Tom Smith
Following our earlier post on a 12-month controlled trial with UDUMA in Mali, we are delighted to share a further update.
UDUMA has confirmed that all 20 Impact Pumps Solution sites continue to work well, with no reported issues since the controlled trial completed in July 2024.
This means the 20-site programme has now delivered three years of continuous operation in challenging rural water conditions in Mali — representing more than 700 cumulative site-months of resilient rural water service operation.
That is an important milestone. The original trial showed that the Impact Pumps Solution could deliver 100% uptime, no outages, no repairs, and reliable water access for approximately 10,000 people across rural Mali. It also showed more than 25% lower installation Capex compared with alternative solar sites and around 50–60% lower operating costs — helping demonstrate a pathway to reliable, financially sustainable and profitable rural water service provision.
For us, the key lesson remains clear: reliable and profitable rural water services depend not only on pump selection, but on resilient site infrastructure, thoughtful operating models, smart approaches to revenue collection, and local service-provider capability.
The continued performance of the IPS sites reflects both the wider site design and the role of FlexExtend as a key component within it. It is also consistent with our broader FlexExtend field experience, where units have now achieved more than 25,000 hours of continuous operation without maintenance.
In Mali and other markets, high-particulate boreholes can create serious challenges for conventional electric submersible pumps, leading to premature replacement, higher costs and avoidable service interruptions. IPS is designed to address these risks at system level, with FlexExtend helping to reduce below-ground vulnerability by keeping serviceable equipment at surface level and avoiding submerged electronics.
The pilot also implemented an innovative approach to revenue generation and collections. Some communities were offered “wholesale deals”, entitling them to use all the water IPS produced each day in exchange for a pre-paid annual fee. The resultant water cost was significantly less than the equivalent prevailing tariff for jerry cans on a volume basis. This “wholesale” tariff innovation had a huge impact – resulting in significant increases in user demand: up to 15.5 times more than under the conventional jerry can tariff approach. Users appreciated having access to much higher quantities of low cost, reliable, safe water and equity increased across the community. IPS’s scalable infrastructure coped well with the resultant demand surge and has remained resilient over the 3 years.
Opportunities for further cost reductions
One area identified as an opportunity to reduce costs further was in the cost of revenue collection for site operators. Despite the success of the wholesale model in reducing payment collections from site users, UDUMA’s service fee continued to be collected through site visits, with substantial associated transport and labour costs. Although it was not implemented in this trial, we launched our PAYG SolarPlex during the trial in response to the need to support low cost, secure, mobile money payments and efficient revenue collection. Indeed it is capable of implementing the “wholesale tariff” using a single secure token for a year of usage.
Our SMS/keypad pre-payment approach is increasingly recognised by leading microgrid operators as well as off-grid Productive Use of Energy (PUE) asset retailers as the most reliable and cost-effective approach to hack-proof remote revenue collection.
Finally, we remain grateful to UDUMA for their continued professionalism and partnership, and pleased that the Impact Pumps Solution continues to demonstrate its potential as a reliable infrastructure and operating model for rural community water service providers throughout the sector and in challenging environments.
If you would like to read the original report, please click this link or contact us for further information.
Note: Mark Bryant is CEO of Thermofluidics and Impact Pumps. Dr Tom Smith is Chief Technology Officer for Thermofluidics and Impact Pumps.