blizita
commented
1 year ago Add the following:
Energy Yield (aka Specific Yield): Unit: kWh/kWp Definition: This represents the Actual installed energy production (in kWh) per installed nameplate solar capacity (kWp). It can also be defined as "Theoretical energy production" minus "Real World System Losses."
Performance Ratio (aka PR): Unit: kWh(actual)/kWh(nominal) Definition: This is a ration of the "actual" (either real world measured or simulated with losses) kWh production over the "nominal" (all modules operating at full efficiency at STC for all daylight hrs) kWh production.
Performance Ratio - PTC (aka PR-PTC): Unit: kWh(actual)/kWh(nominal) Definition: This is a ration of the "actual" (either real world measured or simulated with losses) kWh production over the "nominal" (all modules operating at full efficiency at PTC for all daylight hrs) kWh production.
Temperature Corrected Performance Ratio (aka TPR): Unit: kWh(actual)/kWh(nominal) Definition: This is a ration of the "actual" (either real world measured or simulated with losses) kWh production over the "temperature corrected nominal" (all modules operating at a temperature corrected efficiency and using site temperature conditions at ideal irradiance for all daylight hrs) kWh production.
Capacity Factor (aka CF): Unit: kWh(actual)/kWh(Theoretical_Max): Definition: This is the ratio of the "actual" (either real world measured or simulated with losses) kWh production over the "Theoretical Max" production (all modules operating at full efficiency at STC for ALL POSSIBLE HRS (even night time))
Power Performance Index (aka PPI): Unit: kW (actual) / kW (nominal) Definition: This is the ratio of "actual" (either real world measured of simulated with losses) instantaneous kW array power over "nominal" (all modules operating at full efficiency at STC) instantaneous kW array power.
Those are all the different perf indicators that I found that seem to see wide usage (even though I hate CF). There are some other more scientifically accurate in some way (usually by futzing with the definition of "nominal").
Sources: https://www.linkedin.com/pulse/how-quantify-pv-plant-performance-osvaldo-santos https://sunspec.org/wp-content/uploads/2015/06/SunSpec-PV-System-Performance-Assessment-v2.pdf
cwhanse
E.g., Power Performance Index (PPI), Performance Ratio (PR), weather-adjusted performance ratio.