| Product(s): | WaterSight |
| Version(s): | 10.00. |
| Area: | Documentation |
Overview
The goal of this article is to guide the user on the main steps to identify the pumps where the utility is "spending" more money in terms of energy inefficiency. These costs are estimated in WaterSight according with the following expression:
Pump inefficiency cost = Total Energy cost - Target Energy cost
Where:
- Pump inefficiency cost is also known as Cost difference from target,
- Total energy cost is calculated by multiplying the total energy consumed (based on the actual pump flow and head and efficiency values) with the average energy price,
- Target energy cost is calculated by multiplying the target energy with the average energy price. Target energy is calculated assuming a new pump that would be operating at the target efficiency (defined by the user) for similar operating conditions of flow and head.
Steps
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Make sure that your digital twin has all required information related with pumps uploaded. More information can be found here.
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Define a target efficiency for the pumps, inside Administration >> Settings >> Service expectations.
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Define an average energy price, Administration >> Settings >> Costs.
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Go to the Home Dashboard, to the Pumps section. Take a look at the overall costs (cost difference from target).
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Hover the mouse over the costs number to have a drill into the top 5 pumps in terms of inefficiency costs. Please note that these inefficiency costs are referred to last week.
6. Go to Pumps dashboard and drill in to the pumps details of those with higher inefficient costs (those identified in point 5).
7. In the Pumps detail, change the period (under Manage Series) to cover 1 year period.
8. Take a look at the annual inefficiency costs (cost difference from target) for each of the pumps identified in point 5 as well as the overall annual efficiency
9. These annual inefficiency costs (cost difference from target) correspond to the costs the utility is incurring by having pumps working at efficiencies much lower than the expected ones (the expected target efficiency is defined by the user under Admin >> Settings), for similar operating conditions of flow and head. These costs can help the utility prioritizing the pumps that should be further investigated or intervened, which can include for example inspection, maintenance, or even replacement.
Note: when analysing specifically a potential replacement (due to pump bad sizing for example), you can quickly determine the payback period, by comparing the annual inefficiency costs (for each pump) with the costs of replacing the pump by a new one with the desired/expected efficiency (for similar operating conditions of flow and head). For example if the annual inefficiency costs are about 20 000 dollars per year, and the investment cost (including installation) of a new pump that would be operating at the desired efficiency (target efficiency), is 40 000 dollars, in two years the total investment cost will be automatically recovered.
Please note that this corresponds to a simplified approach (for example an average energy price is assumed when estimating the inefficiency costs), but it can be already very useful to quickly identify the pumps where the utility is "loosing" more money and to open the discussion inside the utility. More detailed studies and analysis should be then carried out by the utility.
Please also note that although the pump efficiency value by itself is very important, it should not be used alone to assess the priority pumps. This is because some pumps may have low efficiencies, but can also have very low flows associated. In these cases, despite the inefficiency value can be low, the annual inefficiency costs are also very low, as the total energy consumed (as well as target energy) is small. Usually priority pumps will correspond to those that are supplying more customers (higher flows and heads) with efficiencies substantially lower than the ones expected.
See Also
OpenFlows WaterSight TechNotes and FAQ's
WaterSight - Learning Resources Guide