Skip to content

Solar Degradation Scenario and Measured Change

Calculate an explicit annual-decline energy scenario or annualized change between normalized measurements; handle zero decline, zero output and measured growth.

Use this result well

Inputs that matter
Year-one generation (kWh), Entered annual decline (%), Whole years modeled, Sources and assumptions, and 3 more
Output to expect
Output under an entered annual decline, Measured normalized performance change
  • Check the units and required inputs before comparing results.
  • Keep the assumptions with a copied result so you can reproduce the calculation later.
Was this tool helpful?

Related Tools

Tools you might need next

Notepad

Simple in-browser notepad with auto-save. Write quick notes that persist in your browser. Download as text file. No signup needed.

Recommended next stepLifestyle
Solar Panel Power and Interval Energy Calculator

Estimate instantaneous PV power from operating conditions or integrate actual AC intervals; keep module temperature, inverter clipping and energy separate.

Solar Energy
Solar Cleaning Period Value Calculator

Value recoverable soiling losses for an entered period using the correct clean or soiled energy baseline, self-use, export credits and cleaning cost.

Solar Energy

Reference & details

How it works

Output under an entered annual decline

Project a chosen constant compound decline from year-one generation. Handle zero decline, full decline and the selected whole-year horizon without a hardcoded equipment-life assumption.

Year-y energy = year-one energy × (1 − annual decline)^(y−1); cumulative energy is the sum of the entered years.

Measured normalized performance change

Compare two positive-duration, weather-normalized generation or performance measurements on the same system basis. An increase is reported as negative decline, without attributing the change to panel aging.

Compound annual decline = 100 × [1 − (later normalized value / earlier normalized value)^(1 / elapsed years)].

Updated: September 2026

Example Scenarios

Try this example to see the calculation, then enter actual documented values and preserve the measurement conditions. A failed or unresolved comparison is part of the record.

→ 7,979.881595 kWh in year 25

Try this example to see the calculation, then enter actual documented values and preserve the measurement conditions. A failed or unresolved comparison is part of the record.

→ 0.448449% compound annual decline

FAQ

Project a chosen constant compound decline from year-one generation. Handle zero decline, full decline and the selected whole-year horizon without a hardcoded equipment-life assumption. Compare two positive-duration, weather-normalized generation or performance measurements on the same system basis. An increase is reported as negative decline, without attributing the change to panel aging.

Use the exact equipment data, measurement point, operating conditions and units described in the selected mode. Record source documents, dates and unresolved conditions in Sources and assumptions. Built-in examples illustrate arithmetic; they are not manufacturer ratings or approved designs.

Use Save planning case for an explicit local history entry. Copy MD keeps current inputs and notes; Download CSV exports the result breakdown. Export portable copies before clearing storage and save a separate case after changing equipment, conditions or measurements.

About Solar Degradation Scenario and Measured Change

Project a chosen constant compound decline from year-one generation. Handle zero decline, full decline and the selected whole-year horizon without a hardcoded equipment-life assumption. Compare two positive-duration, weather-normalized generation or performance measurements on the same system basis. An increase is reported as negative decline, without attributing the change to panel aging.