Defined term

Photovoltaic degradation rate

Photovoltaic degradation rate describes the change in a system or module performance metric over time under a stated method and period.

Also known as PV annual degradation

measurement · Concept code GS-CONCEPT-043 · Last verified August 20, 2026

Definition and boundaries

Definition

Photovoltaic degradation rate describes the change in a system or module performance metric over time under a stated method and period.

Definition claim verification: Verified August 20, 2026

In plain language

When comparing Photovoltaic degradation rate, keep the unit, time period, measurement boundary, and underlying assumptions the same on both sides.

What it is not

It is not a guaranteed annual production decline for every system and it is not the same as a warranty limit.

Decision context

Why it matters

Separate initial stabilization, long-term trend, weather normalization, equipment replacement, outages, and measurement uncertainty before using a rate in a financial model.

Decision-context claim verification: Verified August 20, 2026

Information boundary

This page provides general educational context, not a site design, production guarantee, utility determination, contract interpretation, legal opinion, tax conclusion, or individualized financial advice. Verify property, equipment, utility, jurisdiction, program, and agreement details before acting.

Concept relationships

Affects

  • Annual solar productionPublished conceptPhotovoltaic degradation rate can affect how Annual solar production is evaluated
  • Payback periodPublished conceptPhotovoltaic degradation rate can affect how Payback period is evaluated

Primary sources

What to do next

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