This is a check to gauge how each input parameter affects the capital payment period of each of their respective proposed metering option.
For this outcome, a positive value would indicate that the capital invested in the proposed metering scheme can be retained after a certain time-period. A negative value would indicate the capital invested would never be regained. A low positive value would be the ideal result as it would entail that the metering scheme would pay off the invested capital early in its service life and begin to generate profits.
5.2.1 Conventional metering scheme
For the conventional metering scheme, Figure 5-1 illustrates the capital payment period outcome. The typical capital payment outcome is 134.7 months (approximately 11.2 years) with the outcome ranging from -738.3 months (-61.5 years) to 462.7 months (38.6 years).
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Figure 5-1: Effects of conventional meter input parameters on capital payment period
Upon first observation of Figure 5-1, it can be noted that aside from 4 outcomes (11% of the total outcomes generated), all other outcomes generated are positive values. This illustrates that in most circumstances, capital invested in conventional metering scheme will be regained.
Table 5-1 illustrates the categories of the effects of input parameters for advanced meters. The scale below was used to classify the effects of each metering option.
Non-influential: x < 50 months
Semi-influential: 50 ≤ x < 200 months
Significantly influential: x ≥ 200 months
Where: “x” denotes the modulus difference between the typical value outcome and the range ends outcome. -800.0 -600.0 -400.0 -200.0 0.0 200.0 400.0 600.0
Low Typical High
Capit al Repay men t P er iod Sensitivity Parameter
Effects of changes to Conventional Meter
Parameters on Capital Payment Period
Water Cost Price Applicable water tariff
BMC unit consumption BMC payment rate Water meter failure rate
Vandalism Meter Price Installation Costs Meter reading cost Meter operational and Maintenance cost Billing cost Average meter reading frequency
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Table 5-1: Classification of conventional input parameters based on their magnitude effects on capital payment period
Non-influential Semi-influential Significantly-influential
Parameter x (months) Parameter x (months) Parameter x (months)
Meter price 28.2 Average time of meter
reading 176.7 Meter O&M cost 871.2
Number of properties 0.0 Meter reading cost 132.6 Billing cost 328.6 BMC properties 0.0 Water meter failure 109.8 Applicable water tariff 321.1 Illegal & unbilled
connections 0.0 BMC payment rate 76.2 BMC unit consumption 247.9 On-site leakage 0.0 Installation cost 71.0 Water cost price 202.9
Meter service life 0.0 Vandalism 52.4
Effective service life 0.0
Based on Figure 5-1, meter operational and maintenance cost has the most significant impact followed by billing cost. Their respective low value outcomes are 84.7 months and 78.8 months and their respective high value outcomes are -738.3 months and 462.7 months.
As is illustrated in Figure 5-1 and Table 5-1, operating and running costs and income parameters prove to have the most significant impact on the capital payment period for conventional meters. Capital costs such as meter price and installation costs are not major contributors to the capital payment period.
This could be due to two causes; low capital costs due to the existing infrastructure for conventional metering and the longevity of operating costs and income collected in comparison to capital costs.
Therefore, for conventional meters, operational and running cost and income parameters prove to have the most significant magnitude impact on the capital payment period. This is especially true for meter operational and maintenance cost parameter as well as billing cost as these two parameters had the highest impact respectively.
Though this outcome serves to gauge the time taken to repay capital invested, capital cost parameters do not directly play a significant role to the capital payment period. Changes to its parameters produce little to no changes in capital payment period
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5.2.2 Advanced metering scheme
For the advanced metering scheme, Figure 5-2 below illustrates the capital payment period outcome. The typical value was registered as -72.5 months (-6.0 years) with a range from -230.7 months (-19.2 years) to -42.9 months (-3.6 years).
Figure 5-2: Effects of advanced meter input parameters on capital payment period
The first observation noted from Figure 5-2 is that all outcomes generated are negative values. This alludes that for advanced metering schemes, the capital invested will not be returned and hence implementing advanced water metering system in high income areas in South Africa is not feasible.
However, in order to conduct an adequate sensitivity analysis, the typical capital payment period had to be raised. This was done by raising the typical water cost price from R10/kl to R30/kl.
Figure 5-3 illustrates the change in capital payment period induced by changes to advanced metering input parameter value. The typical capital payment period is 74.5 months
-250.0 -200.0 -150.0 -100.0 -50.0 0.0
Low Typical High
Ca pita l R epa y m ent P er io d Sensitivity Parameter
Effects of changes to advanced meter parameters on
Capital Repayment Period
Number of Properties Water cost price Applicable Water Tariff
BMC unit consumption BMC payment rate Mean battery lifespan Water meter failure rate
Electronics and other components failure Installation cost Communication Infrastructure cost Meter reading cost Meter operation and maintenance cost Average frequency of meter readings
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Figure 5-3: Effects of advanced meter input parameters on capital payment period (adjusted typical value)
Table 5-2 below illustrates the categories of the effects of input parameters for advanced meters. The scales used to classify the effects of each metering option were as follows:
Non-influential: x < 10 months
Semi-influential: 10 ≤ x < 100 months
Significantly influential: x ≥ 100 months
Where: “x” denotes the modulus difference between the typical value outcome and the range ends outcome. -200.0 -150.0 -100.0 -50.0 0.0 50.0 100.0 150.0 200.0 250.0
Low Typical High
Cap ital R e p ay m e n t Per io d Sensitivity Parameter
Effects of changes to advanced meter parameters on
Capital Payment Period (adjusted typical value)
Number of Properties Water cost price Applicable Water Tariff
BMC unit consumption BMC payment rate Mean battery lifespan Water meter failure rate Electronics and other components failure Installation cost Communication Infrastructure cost Meter reading cost Meter operation and maintenance cost Average frequency of meter readings
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Table 5-2: Classification of input parameters based on their magnitude effects on capital payment period
Non-influential Semi-influential Significantly-influential
Parameter x (months) Parameter x (months) Parameter x (months) Communication
infrastructure cost 11.9 BMC unit consumption 80.5 Water cost price 217.5 BMC payment rate 11.5 Installation cost 62.6 Meter price 210.2 Meter reading cost 9.0 Average time of meter
reading 22.4 Applicable tariff 129.6
Mean battery lifespan 8.7 Water meter failure rate 19.3 Number of properties 117.5 Vandalism 4.1 Electronics and other
components failure 19.3 Meter O&M 101.4
Battery replacement cost 1.5
Payment infrastructure cost 1.2 BMC properties 1.1 Billing cost 0.6 Illegal or unbilled connections 0.0 On-site leakage 0.0 Meter service life 0.0 Effective service life 0.0
Based on Figure 5-3 and Table 5-2, water cost price has the most significant impact on the capital payment period for advanced meters followed by the meter price. Their low values generate a capital payment period of -143.0 months and 40.0 months respectively where as their high values result in a capital payment period of 29.6 months and 284.7 months respectively.
For advanced metering, the high capital costs such as communication and payment
replacement costs are not influential. However, meter price and installation cost are influential. Meter service life, on-site leakage and illegal connections have no effect on the capital
payment period for advanced meters.