News

By Mark Bryant and Tom Smith

We are pleased to share the results of our successful 12 month trials of the “Impact Pumps Solution” (IPS) to community water access, deployed by our partner UDUMA to serve 10,000 people across 20 sites in rural Mali. IPS significantly reduced installation capital expenditure (Capex). In its first year of operations, all sites experienced 100% service levels (0 days outage), zero service events (0 repairs needed) and 50% to 60% lower operating costs, laying the foundation for a profitable water service for operators.

The trial tracked operational and financial metrics using UDUMA’s systems and the performance of the 20 IPS sites is compared with 20  comparable “Alternative Solar Solution” (ASS) sites 20 “Handpump” (HP) sites in our joint report “Assessing the Impact Pumps Solution for water services in rural Mali”. Please click this link to download a copy.

What Is IPS?

IPS is a complete site infrastructure design and operating model for solarised water access sites for communities up to 1,500 people. It was conceived to minimise the whole-life cost of providing rural water services, including Capex installation costs and lifetime operational service and maintenance expenditures.  At its core, IPS uses Impact Pumps’ novel SolarPlex Extend pump technology to reduce pump failures and enable a “swap-out” model for serviceable equipment, located at surface level. IPS integrates this core pumping capability into an overall site technical infrastructural design that systematically addresses issues relating to tanks, taps, valves, pipework, meters, ground works, security etc. The reason for this is that our analysis found those elements were responsible for the majority of service failures and related operating costs at solar installations. Our IPS site design for Mali was combined with these insights in a Failure Mode & Effects Analysis (FMEA), developed collaboratively with UDUMA, to reflect general and local Mali-specific risks. The insights could then be factored into an Operations & Maintenance (O&M) regime to ensure longer term systems resilience and efficient service delivery. The outcomes from the trial are underpinned by this systems design approach in combination with an efficient operating model. They provide a route for operators adopting IPS to become more profitable and economically sustainable.

 Highlights of the report include:

• Zero service events at any of the 20 IPS sites (0 days outage and 0 repairs) for the 12 month duration of measured operations on the project c.f. 2 at ASS (58 days outage), and 4 at HP sites (7 days outage).
• IPS site Capex costs consistent with >25% savings compared with ASS sites.
• Initial challenges with low demand (primarily due to site selection) successfully addressed by replacing a “Pay-by-the-Jerry-Can” post-paid tariff structure with a novel solar “IPS Wholesale” pre-paid tariff at 20% of sites. Each IPS Wholesale community able to access all daily water produced on site, in exchange for a pre-paid fixed annual fee – increasing equitable access at volumetric costs far lower than post-paid tariffs.
• Average consumption at IPS Wholesale sites >10x more than post paid sites, during peak dry season. Evidence of IPS’ ability to support local demand surges and seasonal demand variations.
• IPS Wholesale sites’ operating costs were 60% lower than those for ASS sites. Across all IPS sites, operating costs were ~50% lower than for ASS sites.
• Demonstrated ability to operate at very low yielding borehole sites (less than 0.5m3/h recharge) not addressable by standard submersible pumps, subject to daily manual restart (addressable with software changes).

Learnings from the project will enable further cost reductions in future projects, particularly with regards to remotely-enabled revenue collection via our Pay-As-You-Go (PAYG) / mobile money platform, and at low-yielding well and borehole sites which benefit from our ability to match delivered power to borehole yield characteristics. In addition, economies of scale in moving to 200 or 2000 site portfolios will yield further significant procurement and operational cost reductions. Finally, piped networks are well suited to IPS as it is able to distribute water over 4km distances. 

Key systems-design inputs underpinning these results include:

• Directing tank input and output flows in opposite directions using elbows attached to the underside of the tank to create “slow-vortex” sedimentation and the effective separation of raised-air (e.g. due to dry-running in seasonal wells), with pipework exposure also minimised.
• This enables the SolarPlex (surface) drive pump to be operated with pre-sedimented, de-aerated water at above atmospheric pressure (reducing pump impeller wear and NPSH/cavitation), which is not achievable with conventional submersible pumps
• Operating the SolarPlex (surface) drive pump close to Best Efficiency Point (BEP) at all simultaneously varying water depths and (solar) power levels (further reducing pump impeller wear and equipment stresses), which is also not achievable with submersible pumps
• Coupling the SolarPlex with the FlexExtend to lift water up to 45 metres. The FlexExtend enabled key systems-design features including (1) the ability to run dry for extended periods improving drawdown resilience, (2) high tolerance for elevated sand, silt and particulate levels in Mali boreholes, (3) scalability to support local demand surges.
• Extending groundwater lifting expected life: (1) the FlexExtend is designed for 20+ years of reliable operation, (2) it has operated at sites for >30,000 hours (maintenance-free), (3) our entire global portfolio of them continues to operate “failure free” to date.
• Increasing pipe, filter and water meter sizing to reduce water tower height, energy losses and pump loading
• Shading water tanks with solar panels to reduce water heating, tank degradation and panel-mounting costs
• Integrating tap stand, perimeter fencing, solar array and pumphouse into a single cuboid architecture, protecting surface equipment and avoiding pipe trenching and securitisation costs
• Modular system design enabling simple and cost-effective “module” upgrades if later needed to meet increased demand

According to UDUMA, all IPS sites have continued to perform well since the end of the project. More details about the longer-term operation will be published in due course.

We are grateful to our partner UDUMA for delivering this project under the extremely challenging operational circumstances on the ground in Mali, and to Vitol Foundation for supporting our work.

Note: Mark Bryant is CEO of Thermofluidics and Impact Pumps. Dr Tom Smith is Chief Technology Officer for Thermofluidics and Impact Pumps. Photo courtesy of UDUMA.