“Thermofluidics' technology is applicable from industrial state-of-the-art to the poorest people in the world - it is our objective to serve both.
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Our “no-reagents” solar powered chlorinators are ready for field trials at off-grid Community Water Access sites
We are pleased to announce the successful completion of our Innovate UK SMART award project to develop a fully-automated PV-powered water chlorinator for off-grid water treatment without free-chlorine chemicals.
Our DCC chlorinators are solar PV powered. They treat water with no chemical additions, including salt, relying instead on ions naturally present in the source water. This approach combines onsite chlorine production and accurate chlorine dosing into one seamless and fully-automated process, with no dependence on consumable materials and minimal operating costs.
We have two complete field-ready units, with parts available for up to ten. Our Direct Contact Chlorinators (DCC) now reliably treat microbially contaminated water containing 13ppm (13mg/L) or more of chloride ions, to within a user-settable range of 1–5(±0.5)ppm; in line with WHO guidelines. The field-ready units pictured are based around our own proprietary power electronics to modulate electrolyser current with varying flow rates and chloride levels.
Leveraging an ongoing collaboration with Prof. Dan Rogers of Oxford University’s Power Electronics group, our chlorinators connect directly to any PV array with Open Circuit Voltage (OCV) in the range 30–100V, managing all power conditioning (Maximum Power Point Tracking and Voltage Regulation) internally. Users can input a target free chlorine concentration via two buttons with information fed back through a LCD. A simple calibration procedure enables non-chloride contributions to the mineral content of the water to be discounted without baseline water composition testing. The DCC also optionally enables automatic self-calibration via terminals that connect to standard Redox (ORP) and pH probes. A “normally closed” solenoid valve ensures that water is only delivered if it has been treated to within 0.5ppm of the target level.
In order to address water sources containing less than 13ppm free chlorine, or treat larger flow rates with a derived apparatus, we are introducing a salt dosing accessory that pre-seeds the water with common salt. Whilst this accessory does require salt to be brought to site, this is far cheaper than liquid hypochlorite and significantly easier to store. Refill intervals are also improved by an order of magnitude: liquid hypochlorite dosers typically treat 100s of cubic meters of water between refills, whereas we can treat1000s of cubic meters. Using salt instead of hypochlorites or chloroisocyanuric acid tablets avoids the need for expensive and short shelf-life chlorine products and skilled operator-intervention, providing a user-experience equivalent to the occasional “topping-up” of salt in a dishwasher or water softener.
Thermofluidics’ chlorinators are set to transform water treatment, by dramatically lowering the complexity, operational and supply chain costs associated with delivering safe water and protecting users from post-source contamination. For more information, please read earlier news posts below or contact us.
Thermofluidics successfully chlorinates borehole water containing less than 20mg/L of chloride ions to 3ppm with no added reagents
We have successfully completed a second UK trial of our novel PV-powered chlorinator. We were able to treat up to 225 litres per hour of “soft” borehole water to a free-chlorine concentration of 3ppm using solar power alone, on a rainy day in Devon, UK. The borehole water, normally used for cattle watering at Langley Farm in the Exe valley, contains only 16mg/L of chloride ions. This low chloride concentration is below that of approximately one third of water wells in the UPGro database; a publicly available resource covering over 400 wells distributed across Malawi, Ethiopia and Uganda. It is also more than 100 times less than the chloride levels encountered in our first “hard water” trials at our test well in Beckley, Oxfordshire in August 2022. The maximum “soft water” flow we were able to treat increased to at least 350 litres per hour at a lower target free chlorine concentration of 1.5ppm and it increases to over 2000 litres per hour at harder, higher-chloride sites.
Our Direct Contact Chlorinator (DCC) technology involves a novel approach to direct electrolysis of untreated groundwater, liberating naturally-present dissolved chlorides as free chlorine. This approach combines onsite chlorine production – without chemical feedstocks, including salt – and accurate chlorine dosing, into one seamless and fully-automated process. Alongside previous tests carried out, these latest tests also demonstrated that our approach is capable of treating water with rapidly varying flowrate and power availability. This is consistent with the varying power levels and flowrates associated with point-of-use treatment in off-grid/weak-grid public buildings, at community water sites, and in small piped-water networks in the global south. For even lower-chloride sites, we are working on a “Hypochlorite Generator Accessory (HGA)” which automatically dissolves and electrolyses crystalline salt from a salt-reservoir, and doses water to a settable target concentration on site. Whilst this accessory does require salt to be brought to sites, it avoids the need for expensive and short shelf-life chlorine products and skilled operator-intervention, providing a user-experience equivalent to the occasional “topping-up” of salt in a domestic dishwasher or water softener. This project draws on the latest generation C-programmable microcontrollers, expert inputs from Prof. Dan Rogers at Oxford University’s Energy and Power group, and our network of partners in the community water space around the world. It also sits in the context of rapidly decreasing photovoltaic module prices which is driving the African off-grid solar revolution more generally. This powerful combination can bring capabilities previously unthinkable below utility scales to distributed users off water and energy grids.
Our next challenge is to refine our approach to on-site calibration, which enables us to achieve a settable target chlorine concentration without need for baseline analysis – and turn our prototypes into a robust and user-friendly product. To do this, we will draw on the experience we’ve gained on a pipeline of novel off-grid water pump products, commercially available through our subsidiary Impact Pumps. Subject to funding, we anticipate having a DCC ready for field trials with our partners in southern Asia and sub-Saharan Africa in Q2 2023.
Chlorination is by far the most common water sterilisation method used worldwide, and the only method providing residual protection against microbial contamination post-source. Post-source contamination is increasingly understood to be as significant a problem as contamination at source, particularly when water is collected in buckets or jerricans and carried to the home. However, its implementation is currently hindered by limited supply chains for chemical feedstocks, dependence on skilled operators, and routine service/maintenance requirements.
Our novel PV-chlorinator delivers treated water from a contaminated well with no brought-in chemicals for the first time.
Our novel PV-powered chlorinator has successfully treated contaminated groundwater from an old village well close to our R&D base in Oxford, UK, under a range of operational conditions, for the first time.
Our Direct Contact Chlorinator (DCC) technology involves a novel approach to direct electrolysis of untreated groundwater to liberate naturally-present dissolved chlorides as free chlorine. The tests, conducted entirely off-grid, involved treating well-water contaminated with coliforms including e-coli to a target free-chlorine concentration of 2.65ppm. This was done without adding any treatment chemicals or sourced-reagents. These tests also demonstrated that our approach is capable of treating water with rapidly varying flowrate and power availability, consistent with varying power levels and flowrates associated with point-of-use treatment in off-grid/weak-grid public buildings, at community water sites, and in small piped-water networks in the global south.
The trials further provided early verification of our approach to field-calibration (to achieve a target chlorine concentration without prior knowledge of water composition), and failure mode mitigation (predominantly to ensure that only safe water is delivered). Our 2.65ppm target was maintained to within to within 10% of the target value throughout the tests.
Our next challenge is to demonstrate this capability with a variety of groundwater sources in the UK, of significantly varying and unknown chemical solute composition, before packaging the technology up and shipping it out for field trials with our partners in southern Asia and sub-Saharan Africa. Our desk-research indicates that this approach to chlorination is probably viable in approximately one third of water wells in the UPGro database; a publicly available resource covering over 400 wells distributed across Malawi, Ethiopia and Uganda.
We will soon begin work to be able to treat water at most of the two thirds of UPGro sites not suited to this approach, with a Hypochlorite Generator Accessory (HGA). The HGA will automatically treat source water using crystalline common salt as its only feedstock material.
Chlorination is by far the most common water sterilisation method used worldwide, and the only method providing residual protection against microbial contamination post-source. This is increasingly understood to be as significant as contamination at source, particularly when water is collected in buckets or jerricans and carried to the home. However, its implementation is currently hindered by limited supply chains for chemical feedstocks, dependence on skilled operators, and routine service/maintenance requirements.
Thermofluidics takes delivery of controller hardware for our new fully automatic PV-electrolytic chlorinator for off-grid communities
Professor Dan Rogers, key member of Oxford University’s Energy and Power group and Thermofluidics’ power-electronics guru, has handed over a prototype controller for our fully-automated PV-powered water chlorinator. The controller, built around a STM32 microcontroller, will integrate the key components that enable us to offer fully-automated water chlorination for communities without access to water or power-grids.
Chlorination is by far the most common water treatment method worldwide, and the only method providing residual protection against microbial contamination post-source. This is increasingly understood to be as significant as contamination at source, particularly when water is collected in buckets and carried to the home. However, its implementation is currently hindered by limited supply chains for chemical feedstocks, dependence on skilled operators, and routine maintenance requirements.
We will enable automated water treatment to internationally-recognised standards by PV-powered electrolysis, without depending on free-chlorine chemicals such as hypochlorites or chlorinated cyanuric-acids, skilled operators, or expensive and life-limiting components such as RedOx (ORP) and Ph probes. Using a novel approach, we are able to treat many groundwater sources that contain trace levels of natural chlorides without any feedstock materials at all, including common salt. This will result in a practical and cost effective solution to delivering water free from microbial contaminants at a community level off-grid. Later in the project, we plan to integrate an accessory that will enable sources with insufficient natural chlorides to be automatically treated, without batch preparation or operator intervention, using widely-available crystalline salt.
The components of our chlorinator, already working well together with manual control, have since been integrated and controlled by a lab PC using National Instruments’ Labview. The move over to a purpose-built controller represents a major step in our drive to bring affordable water services to all.
Thermofluidics awarded Innovate UK funding to turn our novel PV-powered chlorinator into a commercial product
We are delighted to announce that we have secured Innovate UK funding to turn our successful proof-of-concept solar PV-powered chlorinator into a robust and affordable commercial product.
Our novel approach to solar PV-powered chlorination turns dissolved chlorides, which are present in many groundwater sites around the world into free chlorine, treating water for bacteria and viruses and providing residual protection without depending on bought-in reagents or skilled-operator intervention. The way in which we do this also avoids dependence on expensive life limiting components to keep costs down. For water sources with extremely low or no pre-dissolved chlorides, such as river or pond water, we will introduce an accessory which produces free chlorine and treats the water as it’s drawn off, using crystalline salt as our only feedstock. Unlike existing solutions, our approach does not require batch preparation or routine calibration.
The project, which began on 1st January 2022, will keep our R&D team busy as our subsidiary Impact Pumps scales production of its SLX-40 submersible pump range, harnessing the Joukowski effect to bring reliable access to groundwater, particularly in off-grid areas.
Novel PV-electrolytic chlorination Proof-of-Concept demonstrated in our Oxford lab
Sophia Motteu, graduate chemical engineer and the latest addition to our growing team, has demonstrated a proof-of-concept electrolytic chlorinator in our Oxford lab. The chlorinator, which could enable water to be automatically treated to within WHO guidelines at the tap, could eliminate dependence on free-chlorine reagents and skilled operators on-site. It could be cheaply produced, and widely deployed at water collection points. Leveraging recent trends in power electronics and benefiting from cheap and widely available PV, the solution could cost-effectively treat viruses as well as bacteria, and provide residual protection against contamination beyond the point of collection.
Community Water Access trials demonstrate 92% reduction in down-time
We have completed Phase 1 of our Community Water project in collaboration with FundiFix Ltd. The project has successfully demonstrated that an Impact Pumps Solution can significantly reduce the downtime and lower the operational costs of providing a community water service, potentially by as much as 75%. These results were made possible by the relative ease with which maintenance issues could be identified and remedied, with almost all serviceable parts located at surface level. As intended, the solar surface pump used during the project was “swapped-out” for a petrol-powered backup on a few occasions due to extended-cloud and demand surges, and swapped for an equivalent solar pump after one instance of surface pump failure.
Construction starts on resilient Community Water Access sites in Kitui, Kenya
Construction work has begun at our two Community Water Access phase 1 pilot sites in Kitui County, Kenya, in collaboration with FundiFix Ltd. This comes off the back of 3 months of delays due to the Nairobi Coronavirus curfew, exacerbated by difficulty in managing this project remotely. Thermofluidics’ role in the project has so far involved providing equipment through our subsidiary Impact Pumps and pioneering a complete installation package and bespoke data acquisition and logging capability.
Piezo-electric microphone traces demonstrate potential for reliable low-cost remote monitoring
We have completed a full characterisation of a PS0 Impact Pump at our U.K. test facility, gathering multi-period time-series traces from piezo-electric microphones at several input data points for each parametric variable. The raw data, hot off the press, shows excellent SNR, including a number of features of known or suspected origin, as well as some unknown periodicity. Post processing over the coming weeks and months will reveal more about what real-world information these encode, with a view to introducing on-site data processing and cheap and robust remote-monitoring in the longer term.
First Impact Pumps go live in Zambia
Our first Impact Pump prototypes in Africa beyond Kenya are installed and lifting water from an open well and a drilled borehole for irrigation on a farm near Ndola, northern Zambia. These are PS0 (Pre-Series 0) prototypes, powered by a Futurepump SF2 and Ennos Sunlight pump, respectively. These units were installed by local plumbers with minimal instruction and will be used to conduct a number of farm-based studies as part of a wider project looking at the introduction of sustainable horticultural practices into the region.