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Greenbyte Documentation

Reference Normalized Power

The Production-Based Availability (Inverter Normalized) KPI calculates Lost Production to Performance by evaluating the performance of one inverter against that of all the inverters connected to a Primary meter. The logic is that an individual inverter (and the solar PV array behind it) has the potential to perform as well as all the other inverters on the site, and thus a peer review of an individual’s performance against the top-performing inverters is useful.

This signal defines this benchmark reference value from the Normalized Power signal calculated for each inverter. The benchmark value is defined as the average power of the top 50% highest performing inverters mapped to the same primary meter as the inverter.

Reference_Normalized_Power_-_Description.png
Technology

Solar

Remarks

This is a helper signal used as an input in Denormalized Power and is part of the greater Production-Based Availability (Inverter Normalized) calculation. For this signal to have a value, it must follow the Rules for Referencing Devices that concerns Primary meter mapping, and that all inverters mapped to the same primary meter have a Normalized power value.

Equation

In each time step the reference normalized power is calculated like this:

Reference_Normalized_Power_-_Equation.png

Where:

Pnorm,ref

is the Reference normalized power

Pnorm

is the Normalized Power

n

is the total number of inverters mapped to the same primary meter as the inverter

Inputs
Reference_Normalized_Power_-_Inputs.png
Usage Example

Reference Normalized Power is plotted against Normalized Power and Effective Power here, showing that this Inverter 1-1’s Actual Power (Effective Power) fell long short of the performance of the top-performing 50% of inverters. By contrast, Inverter 8-1’s Effective Power was much closer to that of the top-performing inverters. Note that, the figure for Reference Normalized Power (99.34 kW Avg.) is the same for both inverters since they are connected to the same primary meter.

Reference_Normalized_Power_-_Usage_Example.png