Key Performance Indicators for Solar PV Plants.

Specific yield (kWh/kWp) is the energy (kWh) generated per kWp module capacity installed over a fixed period of time. Indirectly it indicates the number of full equivalent hours a plant produced during a specific time frame.

Daily Specific Yield (kWh/kWp)= Daily Energy / DC Capacity

Example: If a 5 kW DC Capacity plant produces 21 kWh on a particular day
Its Specific Yield for that particular day = 21/5 = 4.2 kWh/kWp

Benefits

• – Specific yield parameter normalizes plant output over a chosen time frame and thus allows the comparison of the production of plants with different power plants or even different power production technologies.
• – By comparing inverter level-specific yields within a power plant, it is possible to detect which of an inverter are performing better than others.

CUF is output of the plant compared to theoretical maximum output of the plant in specific period of time.

Daily CUF (%) = Daily Energy (kWh) / (Plant Capacity (kwp) x 24 )

Yearly CUF (%) = Year Energy (kWh) / (Plant Capacity (kwp) x 24 x 365)

The performance ratio (PR) is stated as percent and describes the relationship between the actual and theoretical energy outputs of the PV plant. It thus shows the proportion of the energy that is actually available after deduction of energy loss (e.g. due to thermal losses and conduction losses ).

There are multiple methods of calculating PR and are explained in detail in this article: https://trackso.in/knowledge-base/performance-ratio-calculation-trackso/

Performance Ratio Calculation by Trackso

Solar Insolation is amount of the solar energy that is incident on a specified area over a set period of time. (kWh/m2)

Insolation for a given period of time = ∫ (irradiation value).dt

– Insolation data can help to determine the expected output for a solar plant

A detailed article on how to calculate Solar Insolation for a Solar Power Plant is available at link- https://trackso.in/knowledge-base/how-to-calculate-solar-insolation-for-a-solar-power-plant-using-solar-radiation/

How to Calculate Solar Insolation (kWh/m2) for a Solar Power Plant using Solar Radiation (W/m2)

Expected Energy Today: Energy today * 100 /PR * 0.82

Assumption- 82 % is an ideal PR for well designed and well-maintained plant

Deemed Generation (During Power Cut / No Grid) = 0.82 * Insolation during the time period * Capacity

Deemed Generation (During Power Control) = (0.82 * Insolation during the time period * Capacity) – Energy generated during that Period

Assumption- 82 % is an ideal PR for well designed and well-maintained plant