PV Inverter Availability from the U.S. PV Fleet

Research output: NRELPoster


In the PV Fleet Performance Data Initiative, we partner with photovoltaic (PV) fleet owners to collect time-series PV production data, and publish aggregated, anonymized results. An assessment of system availability is conducted on 1128 systems which passed our data quality checks, and include cumulative energy meter data. Overall inverter availability is low in the first 6 months of system performance before reaching steady-state by the end of the first year. System-level aggregated data shows a median (P50) system availability of 0.99, and a lower P90 value of 0.95. A dependence on system size is also identified, with better inverter availability results for smaller PV systems. Potential causes of this effect may include the selection of inverter itself: smaller inverters 6kW-250kW showed better average availability than inverters 300kW-5MW. The elimination of string combiner boxes and lower energy impact when one particular inverter goes off-line are potential benefits of a string inverter-based PV system architecture. DNV also analyzed availability data from over 1100 operating systems and found similar trends. DNV's P50 industry guidance on expected availability has been updated to reflect the data and the following observations: utility scale systems have lower availability than DG systems, availability is lower in first year compared to subsequent years, and that actual availability is lower than expected.
Original languageAmerican English
PublisherNational Renewable Energy Laboratory (NREL)
StatePublished - 2024

Publication series

NamePresented at the Photovoltaic Reliability Workshop (PVRW), 27-29 February 2024, Lakewood, Colorado

NREL Publication Number

  • NREL/PO-5K00-88986


  • fleet
  • inverter availability
  • operating systems
  • photovoltaic
  • PV availability


Dive into the research topics of 'PV Inverter Availability from the U.S. PV Fleet'. Together they form a unique fingerprint.

Cite this