Flowmetering key to conservation in Middle East
The Middle East is facing massive pressure to manage and conserve its water supplies to meet rapidly escalating demand. Tim Door, flow product manager with Swiss technology company ABB, explains the role that flowmetering technology can play in meeting these challenges and highlights how it is already helping some parts of the Middle East to transform water network efficiency.
With 5% of the world's population, but just a 1% share of the global freshwater resources available to supply them, Middle Eastern countries face massive issues when it comes to water provision and management. Studies have highlighted that many parts of the region are already withdrawing 100% or more of their renewable water resources, with predictions estimating a steady escalating demand for water from 170 billion m3 in 2000, to 228 billion m3 by 2025.
Based on this figure, it is estimated that the regional average water availability for the Middle East and North Africa will be just over 500m3 per person per year, in stark contrast to the world average of 7000m3. Countries such as Jordan and Yemen already have less than this, with a typical average of just 200m3.
Despite this, existing policies in the region are still tending to be directed at increasing supply rather than prioritising demand management. Investment in outdated networks is also being hampered by inadequate cost recovery, with few mechanisms in place for operators to recoup their costs from end-users.
Where managing existing water supplies is concerned, the solutions tend to fall into three main categories: improving operator performance, decentralising responsibility for water networks to the local level or managing water resources more effectively. Many Middle Eastern countries have leaking water networks and there is a need to identify both how much water is being lost and where and when these leaks are occurring, therefore, it is necessary to first be able to accurately match the amount of water being supplied with the amounts consumed by end-users.
Electronic flowmeters have been around for some time, yet, with the exception of the MagMeter, they have generally been slow to be adopted by the water industry, due mainly to a comparatively higher purchase cost than mechanical metering equipment. Simple to operate and with a low price tag, mechanical meters have long been seen as the more attractive flowmetering option.
However, although apparently more economical in the short-term, mechanical meters suffer from serious drawbacks that can lead to operators incurring additional costs further down the line. Foremost amongst these is the steady deterioration in accuracy caused by wearing of mechanical components.
Whilst a loss of accuracy of a few percentage points may not appear that significant, the potential loss of revenue that this represents is becoming of increasing interest as water companies look for ways to achieve more precise flow measurement and improve their profitability. The meter's total cost of ownership is important to consider when assessing its value.
This includes not just the cost of maintaining the meter, with its associated disruption as the meter is removed from the line, but also the cost of sending someone to manually collect information from several meters at a time. This can add up to a significant level of expenditure over the life of a meter.
Where long-term costs are concerned, the arguments in favour of electronic meters are compelling. In most cases, payback on the installation of an electronic flowmeter could actually be achieved in a matter of days, as demonstrated by the following example.
To take a mechanical 152mm flowmeter that is accurate to within ±2%. This flowmeter is installed in a line with an average flow rate of 110m3/h, which equates to an annual usage of 963,600m3.
Assuming a cost just for water is US$1.09/m3, over the course of one year, the inaccuracy of the meter would be losing the operator around US$15,746 of revenue. Based on this estimate, payback on the installation of an electronic flowmeter could be achieved within three months.
There are also other areas where an electronic meter can achieve savings. There are no mechanical moving parts that can be subjected to wear and which will need to be replaced.
This not only ensures that the meter's accuracy is constant throughout its service life, but eliminates the cost, time and disruption associated with removing the meter from the line for maintenance. Developments in remote communications technology also mean it is now no longer necessary for staff to be deployed to read meters or check on their status. Incorporating GSM communications technology into flowmeters can provide operators with instant access to real-time data and also historical flow datalogged by the meter.
Using in-situ calibration equipment, flowmeters buried underground or installed in underground chambers can now also be tested from the surface via a laptop computer, enabling easy and cost-effective performance checks without interrupting the continuity of water supply. This equipment can also be used to provide a diagnostic health check on the entire flowmeter system together with an early warning of any deterioration likely to lead to system failure.
Installations in Kuwait, Jordan and Qatar are providing proof of how installing electronic flowmeters can help to transform network efficiency. In Kuwait, 85 electronic flowmeters have been supplied to the Kuwait Ministry of Electricity and Water (MEW) to replace orifice plate meters installed for over 20 years.
The flowmeters can ensure high accuracy even at extremely low flow rates, are cheap to install and using the GSM communications function, will enable the Ministry to remotely access metering data on a daily basis. Previously, this data had to be collected manually every four weeks from each of MEW's 400 key metering locations.
MEW's original scheme of installing a SCADA network to remotely collect data from each flowmeter was impractical, due to the cost of installing cabling over such a wide area and because of the lack of available power sources to supply the network. A substantially reduced cost of ownership and a 45% reduction in installation costs with the future option of GSM communications made ABB's AquaMaster electromagnetic flowmeter an obvious choice for this long-term project.
A further 22 units supplied to the Amman Water Company in Jordan have helped to solve a problem with water hammer, which had rendered useless many previously installed mechanical flowmeters. Jordan's water supply network is frequently shut down for several days at a time to help conserve water.
Previously, whenever the supply was restored, residual water in the pipeline was being propelled at pressures of up to 40 bar g, severely damaging the moving parts of many mechanical flowmeters installed throughout the network. Electronic flowmeters have overcome this problem. With no mechanical parts, they can handle any sudden surges that occur whenever the water supply is restored.
ABB has also supplied some 600 AquaMasters to the national utility company of another Middle East country. Its strategic plan is to manage its water distribution network more effectively, by comparing readings taken by flowmeters strategically positioned throughout its distribution network with the readings from customers' water meters. In this way it is planned to detect leaks more effectively and minimise water loss.
Accurate flowmetering is just one of the many water supply and management challenges facing Middle Eastern countries. However, the ability to derive greatly enhanced measurement accuracy and levels of information, makes adopting modern flowmetering technology an invaluable starting point for designing strategies to tackle many of these problems.