Understanding Meter Discrepancies
Meter discrepancies occur when two systems measuring the same output report different results. These differences can arise from various factors, such as background energy consumption, signal loss or gaps in data recording. Identifying and addressing these issues is crucial for maintaining accurate energy reporting and improving operational efficiency.
This analysis focuses on two real life examples
Borehole pumps: A low-risk example with minimal discrepancies
Heating and chilling pumps: A more complex scenario where multiple factors contribute to differences
Example 1 – Borehole Pumps
The first case involves four pumps where the percentage difference between meters is low, averaging around 5% with variations ranging from 3% to 10%. This variance is attributed to one meter capturing additional background energy consumption, such as alarms or screen power usage, often referred to as parasitic[1] loads.
Key Observations
Summer impact: Discrepancies are more noticeable in summer months when overall energy usage is lower, making background loads a larger percentage of total consumption. For example, the difference is 3% in December but rises to 10% in July 2024 (see Figure 1).
Figure 1: The monthly change in difference between the two metering systems
Small fluctuations: The fluctuations seen in figure one are likely due to one meter having an interval of 15 minutes whereas the other is one hour (see Figure 2, 3).
Figure 2: Pump July meter difference caused by different meter intervals
Figure 3: Pump February meter difference caused by different meter intervals
Minimal concern: Despite the differences, these variances align with expectations and present no significant operational risk.
Erda’s analysis confirms that these discrepancies are well understood and accounted for, ensuring that system performance remains reliable.
Example 2 – Heating and Chilling Pumps
The second case involves three pumps with more pronounced differences between metering systems, particularly during summer (see Figure 4), with the notable exception of March, this is explained below. Several contributing factors were identified.
Figure 4: The monthly change in difference between the two metering systems
Key Observations
Unexplained data spikes & troughs: Occasional spikes in one meter’s readings, such as those observed in March, contribute to additional discrepancies. While these spikes account for only a few kilowatt-hours (2 kWh), they require further investigation (see Figure 5, 6).
Figure 5: An example of small differences causing huge percentage disparity
Figure 6: Single troughs during pump activity
Signal loss: One meter experiences periodic signal loss, leading to gaps in data recording. These gaps occur at regular intervals but have improved significantly, with no gaps exceeding two hours since June 2024 (see Figure 7).
Figure 7: Data gaps resulting in lower overall values
Parasitic[1] loads: As with the borehole pumps, one meter captures background energy usage that the other does not. This issue is most apparent in summer months when the pump is inactive, causing a higher percentage discrepancy (see Figure 8).
Figure 8: Showing parasitic power as the pump is not in use
Addressing Discrepancies through Erda’s Aftercare
Erda’s aftercare services are designed to identify and resolve issues like these, ensuring systems continue to perform at their best. With a data quality accuracy rate of >95%, Erda is committed to achieving 100% by addressing the following:
Parasitic[1] Loads
– Fully calibrating meters to account for background energy usage
-Adjusting reporting systems to reflect actual consumption more accurately
Signal Loss
-Investigating and mitigating causes of data gaps through improved hardware and software solutions
Data Spikes
-Conducting detailed analysis to determine the root cause of unexpected spikes and implementing long-term fixes
Why Accurate Metering Matters
Accurate metering is essential for maintaining energy efficiency, reducing costs, and meeting sustainability goals. By proactively addressing discrepancies, Erda ensures that clients benefit from:
-Reliable energy reporting
-Optimised system performance
-Continuous improvement in efficiency
Erda’s Commitment to Excellence
As a leader in geo-exchange systems, Erda prioritises accuracy and reliability at every stage, from installation to ongoing aftercare. By identifying and addressing metering discrepancies, we help our clients achieve maximum efficiency and move closer to achieving their Net Zero goals.
For more information about how Erda’s aftercare services can optimise your energy systems, contact us at info@erdaenergy.com
[1] Parasitic Load: Background energy usage by devices or components that do not directly contribute to the pump’s operation but are still measured by some meters.