The Background
Globally, the supply of clean water to rural communities is “broken” and not sustainable. For decades Government agencies and NGOs have repeatedly installed expensive water systems that quickly fall into disrepair and stop working due to lack of maintenance, faults and indifference, forcing people to go back to using contaminated wells and ‘dirty’ surface water with huge implications to health and wellbeing. A trip across rural Africa reveals village after village with empty water tanks and broken hand-pumps and people returning to using buckets lowered into Mosquito infested wells.
Historically many attempts have been made to provide sustainability with village appointed water managers in charge of water pumps and “locked” water kiosks, with individuals trying to collect money to provide funds for repair and maintenance. In practice, corruption, inconsistency, and a lack of transparency coupled to an absence of training and knowledge prevent these operations from succeeding.
Broken & abandom handpumps
The Solution
In response to providing sustainable clean water supplies, IDE Concepts was contracted by a Water Services provider to design and develop a PAYG (Pay-As-You-Go) pre-payment water dispensing / metering tap for fitting to existing water supply standpipes and new installations. The water meter is operated by means of an RFID (Radio Frequency Identification) contactless tag where credit stored on the tag is deducted in real-time as water is dispensed. The water supply is paid for by pre-charging the tag with credit and the resulting revenue facilitates a business plan to encourage responsibility for the clean water supply and provide employment for local “Water Management” and maintenance technicians. Credit and water usage, system events and data logging information are stored locally and transmitted to Cloud services maintaining IoT (Internet of Things) connectivity and control.
Tag credit can be purchased from a local shop keeper using an NFC enabled smart phone to write credit to a tag or in areas with poor mobile internet (data services), the user can “buy” credit using SMS based mobile money services such as M-Pesa, Tigo-Pesa, Airtel Money etc. In this case “credit” is transferred to a local tap and a user is prompted to collect the credit like an ATM (with the tap writing credit to the authorised tag).
The water supply therefore becomes 24/7 and autonomous with pre-emptive maintenance and diagnostics through IoT messaging with the income generated paying for repair, benefitting local education, training, and responsibility for sustainability.
The RFID water dispenser / metering system
The Technology
IDE Concepts has designed and developed a modular water dispensing and metering system that comprises of a solar charging and power management PCB and a main Controller PCB that integrates the RFID tag read / writer, metering (pulse counting), valve operation, datalog storage and overall control functionality. Together with a third-party GSM module that connects to Cloud based dashboard and database services the system is an IoT (Internet of Things) device. Bi-directional data provides control, real-time data reporting and historic data on request.
Innovative techniques have been used for power management to reduce average power consumption using periodic wake/sleep cycles whilst ensuring 24/7 operation. A unique serial number (UID) and proprietary software encryption techniques are used to identify users and secure data on the tag. All user dispensing events and errors are time stamped, with all metered data stored in on-board memory and transmitted using a messaging protocol. In addition to datalogging and transmission the Controller implements a real-time command and response protocol that allows the tap to be controlled, parameters changed, and the system monitored at any time.
The overall design philosophy has been to “keep it simple” with cost-effective, real-world, and robust design techniques used throughout to handle the harsh environmental conditions. A fundamental requirement was for the system to be able to operate and provide water 24/7 without connectivity. Users can continue to collect water using their tags without any GSM signal, data is stored locally and can be retrospectively read and backfilled when connectivity is restored.
The Evolution
Using real-world feedback from the installed tap and water systems, the RFID water dispenser / meter continues to evolve. IDE Concepts has designed and implemented an optional OLED display to give users more information on credit, price, quantity of water dispensed and other parameters.
An optional MicroSD card module also allows the storing of bulk datalogging events and errors for systems with no or limited connectivity and to provide a totaliser for data integrity.
OLED display option
To complement the complete water infrastructure, a multi-channel sensor and control interface module for the tap has also been designed by IDE Concepts to provide control and monitoring at the water source. Bore-hole pumps can be controlled remotely, bulk flow meters read, and water tank depth monitored using 4-20mA sensors.
Water source control and tank depth monitoring