Measuring Degradation Rates of PV Systems Without Irradiance Data

Alex Cronin, Stephen Pulver, Daniel Cormode, Dirk Jordan, Sarah Kurtz, Ryan Smith

Research output: Contribution to journalArticlepeer-review

10 Scopus Citations


A method to report photovoltaic (PV) system degradation rates without using irradiance data is demonstrated. First, a set of relative degradation rates are determined by comparing daily AC final yields from a group of PV systems relative to the average final yield of all the PV systems. Then, the difference between relative and absolute degradation rates is estimated using a Bayesian statistical analysis. This approach is verified by comparing to methods that utilize irradiance data. This approach is significant because PV systems are often deployed without irradiance sensors, so the analysis method described here may enable measurements of degradation using data that were previously thought to be unsuitable for degradation studies.

Original languageAmerican English
Pages (from-to)851-862
Number of pages12
JournalProgress in Photovoltaics: Research and Applications
Issue number8
StatePublished - 2014

NREL Publication Number

  • NREL/JA-520-49385


  • degradation
  • irradiance
  • photovoltaic test yard
  • yield


Dive into the research topics of 'Measuring Degradation Rates of PV Systems Without Irradiance Data'. Together they form a unique fingerprint.

Cite this