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Greenbyte Documentation

Lost Production to Performance (Inverter Normalized)

This signal, used as part of the Production-Based Availability (Inverter Normalized) calculation method, estimates the lost production due to inverter under-performance by comparing the Denormalized Power (Potential Power) with the Effective Power (Actual Power) for each inverter:

Lost_Production_to_Performance__Inverter_Normalized__-_Description.png

If set, the Underperformance threshold (%) metadata field (Inverter metadata 36) will be used to determine if the inverter is really underperforming. That will be done by comparing the inverter’s Normalized Power with its Reference Normalized Power. For more information, see Equation. If the threshold is not met, the Lost production to Performance (inverter normalized) will return 0.

Technology

Solar

Remarks

Not to be confused with Lost Production to Performance (Inverter) (ID 3224).

This inverter signal is dependent on all inverters mapped to the same Primary meter.

Negative values are not allowed.

In order for this signal to have a value, it must follow the Rules for Rules for Referencing Devices that concern Primary meter mapping and that Denormalized power and Effective power have values.

The Lost production to Performance (inverter normalized) signal will return a 0 value only if all those inverters are offline, that is, if the primary meter’s Energy meter-based availability equals 0.

If the inverter is offline while any other of those inverters are online, the offline inverter’s lost production will still be allocated to Lost production to Performance (inverter normalized).

Optional metadata fields:

  • Underperformance threshold (%) (Inverter metadata 36)

Equation
Lost_Production_to_Performance__Inverter_Normalized__-_Equation.png

Where:

ELPP,normalized+

is the Lost production to Performance (inverter normalized), clamped to the positive part

U

is the inverter’s Underperformance threshold (%) (Inverter metadata 36)

Pnorm

is the Normalized Power

Pnorm,ref

is the Reference Normalized Power

Aenergymeter

is the Energy Meter-Based Availability of the primary meter

Pdenorm

is the Denormalized Power

Peffective

is the Effective Power

T

is the device resolution in hours

Inputs
Lost_Production_to_Performance__Inverter_Normalized__-_Inputs.png
Usage Example

Here are graphs for two inverters showing Lost Production to Performance together with Lost Production to Downtime, when the inverters are underperforming compared to the top 50% of performers:

Lost_Production_to_Performance__Inverter_Normalized__-_Usage_Example_1.png

The Energy meter based availability shows that the meter is available, with the Lost Production due to Performance being the difference between the Effective Power and Denormalized Power lines:

Lost_Production_to_Performance__Inverter_Normalized__-_Usage_Example_2.png

Since the Production-based Availability (Inverter Normalized) calculation has the option to include an Underperformance threshold, the amount of Lost Production to Performance registered will vary according to the threshold set. The Underperformance threshold (%) can be adjusted in Administrate/Devices and then click on the menu next to the desired inverter > Edit > Metadata tab:

Lost_Production_to_Performance__Inverter_Normalized__-_Usage_Example_3.png

An Underperformance threshold of 80% is common for most customers, so if the Lost Production to Performance has a reading of 0, this may be because the losses are too small to be registered, that is, less than 20%.

The following graph shows that with a lower threshold, some of the Lost Production to Performance will not be counted:

Lost_Production_to_Performance__Inverter_Normalized__-_Usage_Example_4.png
Lost_Production_to_Performance__Inverter_Normalized__-_Usage_Example_5.png

If we wish to drill into the detail of when the inverter had high or low performance, we should build two line graphs. The following figure shows the energy figure of the Lost Production to Performance:

Lost_Production_to_Performance__Inverter_Normalized__-_Usage_Example_6.png

The following figure shows the data in terms of power. The difference between Denormalized Power and Effective Power, once multiplied by time, gives us our Lost Production to Performance figure:

Lost_Production_to_Performance__Inverter_Normalized__-_Usage_Example_7.png