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Title: PV Fleet Performance Data Initiative: Performance Index-Based Analysis

Abstract

In this analysis, we report on 250 PV systems throughout the US, comprising 157 MWdc of system capacity and over 10,000 monthly PI values based on high-frequency (subhourly) energy data and satellite-based resource data. The distribution of PI values is analyzed, and multiple causes of underperformance are assessed, including first-year startup issues, snowfall and inverter downtime. An initial distribution of raw monthly PI values was collected with mean measured / modeled performance of PI = 0.935. After correcting for the three identifiable loss factors mentioned above, an average monthly performance of PI = 0.994 was obtained, with a distribution closely following a Gumbel Extreme Value distribution. In particular, inverter availability was found to contribute a system energy loss of 2.3% on average, except in the first six months of operation when availability losses are closer to 8%. Other startup issues beyond inverter downtime such as partial string outage contributed an additional 5% underperformance in the first year of operation across the fleet. Winter performance was also found to be 5%-10% below summer performance on average, likely due to snowfall. A simple linear relationship was found between snow loss and monthly snowfall accumulation in cm, indicating between 6% - 40% lossmore » in months with nonzero snowfall, depending on climate.« less

Authors:
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1];  [1];  [1]; ORCiD logo [1];  [1]; ORCiD logo [1];  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
OSTI Identifier:
1766838
Report Number(s):
NREL/TP-5K00-78720
MainId:32637;UUID:162e5942-e1a9-4b0a-9d9a-337ea42c241c;MainAdminID:19300
DOE Contract Number:  
AC36-08GO28308
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; PV; degradation; loss factor; snow; availability; fleet

Citation Formats

Deline, Chris, Anderson, Kevin, Jordan, Dirk, Walker, Andy, Desai, Jal, Perry, Kirsten, Muller, Matt, Marion, Bill, and White, Robert. PV Fleet Performance Data Initiative: Performance Index-Based Analysis. United States: N. p., 2021. Web. doi:10.2172/1766838.
Deline, Chris, Anderson, Kevin, Jordan, Dirk, Walker, Andy, Desai, Jal, Perry, Kirsten, Muller, Matt, Marion, Bill, & White, Robert. PV Fleet Performance Data Initiative: Performance Index-Based Analysis. United States. https://doi.org/10.2172/1766838
Deline, Chris, Anderson, Kevin, Jordan, Dirk, Walker, Andy, Desai, Jal, Perry, Kirsten, Muller, Matt, Marion, Bill, and White, Robert. 2021. "PV Fleet Performance Data Initiative: Performance Index-Based Analysis". United States. https://doi.org/10.2172/1766838. https://www.osti.gov/servlets/purl/1766838.
@article{osti_1766838,
title = {PV Fleet Performance Data Initiative: Performance Index-Based Analysis},
author = {Deline, Chris and Anderson, Kevin and Jordan, Dirk and Walker, Andy and Desai, Jal and Perry, Kirsten and Muller, Matt and Marion, Bill and White, Robert},
abstractNote = {In this analysis, we report on 250 PV systems throughout the US, comprising 157 MWdc of system capacity and over 10,000 monthly PI values based on high-frequency (subhourly) energy data and satellite-based resource data. The distribution of PI values is analyzed, and multiple causes of underperformance are assessed, including first-year startup issues, snowfall and inverter downtime. An initial distribution of raw monthly PI values was collected with mean measured / modeled performance of PI = 0.935. After correcting for the three identifiable loss factors mentioned above, an average monthly performance of PI = 0.994 was obtained, with a distribution closely following a Gumbel Extreme Value distribution. In particular, inverter availability was found to contribute a system energy loss of 2.3% on average, except in the first six months of operation when availability losses are closer to 8%. Other startup issues beyond inverter downtime such as partial string outage contributed an additional 5% underperformance in the first year of operation across the fleet. Winter performance was also found to be 5%-10% below summer performance on average, likely due to snowfall. A simple linear relationship was found between snow loss and monthly snowfall accumulation in cm, indicating between 6% - 40% loss in months with nonzero snowfall, depending on climate.},
doi = {10.2172/1766838},
url = {https://www.osti.gov/biblio/1766838}, journal = {},
number = ,
volume = ,
place = {United States},
year = {2021},
month = {2}
}