Prometheus sum_over_time only when the value is above a threshold

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I currently use the following query to get the kwh drawn from the grid for this year:

sum_over_time( (sum_over_time(wattage_v1[1m])*360/1000/count_over_time(wattage_v1[1m]))[1y:1h] )

EDIT: This query seems to deliver basically the same result:

sum_over_time(wattage_v1[1y:1h])*360/1000

The metric wattage_v1 provides wattage¹ readings every 15s to 1m. The query above seems to work. Now I would like to have a similar query which only sums the wattage value if it is above a threshold - say 4000w. I want to roughly estimate the (yearly) consumption of a big consumer that is only running from time to time.

¹ actually 1/360 watt

Thanks

EDIT: I have noticed that the graph doesn't increase monotonic if the range (1y from above set to 1d for example) is smaller than the actual data that is present. I would like to have a counter for the kwh consumed since the beginning of the year or for the selected time range.

grafana prometheus promql
1 Answers

The following promql query should return the total energy consumption in Joules for minutes with over 4kW power usage during the last year ending at the current timestamp:

sum_over_time(
  (wattage_v1 > 4000)[1y:1m]
) * 60

This query uses PromQL comparison operator and Prometheus subquery feature.

If the result must be converted from Joules (aka watt-seconds) to more commonly used kilowatt-hours (aka kWh), then it must be divided by 3600000:

sum_over_time(
  (wattage_v1 > 4000)[1y:1m]
) * 60 / 3600000

P.S. I work on Prometheus-like monitoring system - VictoriaMetrics, which provides additional useful functions for energy consumption calculations:

  • integrate is for calculating the integral over some metric such as power draw. For example, integrate(wattage_v1[1y]) would return energy consumption in Joules over the last year ending at the given timestamp.
  • running_sum is for calculating the running total over some metric. For example, the following query returns the running total (aka counter) of energy consumption in kWh over arbitrary time range:
running_sum(integrate(wattage_v1)) / 3600000
user_2749370
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