About the Plant Loss Breakdown

Plant Loss Breakdown (or energy waterfall) maps every loss between the solar resource striking the array and the net energy exported to the grid — following the IEC 61724 chain: irradiation → DC generation → inverter losses → AC losses → transformer losses → net energy. It tells you where your plant is losing value and what fixing each loss stage would recover.

Formula

How to calculate it

1. 1Start with gross irradiation (GHI) and apply tilt/azimuth correction to get in-plane irradiation.
2. 2Apply soiling loss (2–15% depending on location and cleaning frequency).
3. 3Apply temperature loss (0.3–0.4%/°C above 25°C; typically 5–12% annual average in India).
4. 4Apply shading and row-to-row losses (0–5% depending on row spacing and obstructions).
5. 5Apply mismatch loss (0.5–2%) and wiring/DC loss (<1% for well-designed systems).
6. 6Apply inverter efficiency loss (typically 2–4% for string inverters including MPPT and conversion).
7. 7Apply transformer and AC cable losses (0.5–2%).
8. 8The remaining energy is net AC generation. The ratio of net AC to irradiation × nameplate is the PR.

Worked example

A 1 MWp plant in Rajasthan: gross GHI 2,100 kWh/m²/yr, in-plane 2,200 kWh/m². Losses: soiling 5%, temperature 8%, shading 1%, mismatch 1%, DC wiring 0.5%, inverter 3%, transformer 1.5% → PR ≈ 80.5%. Net generation = 2,200 × 1,000 × 0.805 = 17.7 L kWh/year.

What you can calculate

• 9-step waterfall
• Net PR
• Loss per stage
• IEC 61724

Standards & references

Key definitions

Definitions from the SolarPedia glossary

Frequently asked questions