Introduction

Started in 2016, the PV Lifetime Project is measuring PV module and system degradation profiles over time with the aim of distinguishing different module types and technology. Outdoor energy monitoring in different climates are supplemented with regular testing under repeatable test conditions indoors. The focus is the PV module, as well as other hardware components (junction boxes, bypass diodes, and module-level electronics) attached to it. Hardware has been installed at Sandia National Laboratories in New Mexico, at the National Renewable Energy Laboratory in Colorado, and at the University of Central Florida.  The systems are continuously monitored for DC current and voltage, as well as periodic I-V curves at the string level.  This data enables an increase in the accuracy and precision of degradation profiles used in yield assessments that support investments made in new PV plants.

Figure 1. Degradation rates of PV modules are often calculated using only one or two data points; for aged PV modules, intermediate performance values are seldom available¹. Differences in how PV modules might reach their end-of-life capacity have substantial impact on levelized cost of energy (LCOE). As an illustration, LCOE values for the typical, linear, 0.5%/year degradation rate are shown along with a notional two-step degradation profile: degradation for the first 12.5 years is 0%/year, followed by 1%/year for the remainder of the 25-year period.  For this example, a discount rate of 7% was assumed.

¹ Jordan, D. C., Kurtz, S. R., VanSant, K., and Newmiller, J. (2016) Compendium of photovoltaic degradation rates. Prog. Photovolt: Res. Appl., 24: 978–989. doi: 10.1002/pip.2744.

More Information

• PV Lifetime Modules Under Test
• Field System Deployments
• Indoor Flash Testing of PV Lifetime Modules

Nov. 29, 2016: Check out the news story about the project and installations in Colorado.

 

Publications

• Theristis, M., J. S. Stein, C. Deline, D. Jordan, C. Robinson, W. Sekulic, A. Anderberg, D. Colvin, J. Walters, H. Seigneur, B.H. King. (2022). “Onymous early-life performance degradation analysis of recent photovoltaic module technologies.” Progress in Photovoltaics https://doi.org/10.1002/pip.3615.
• Driesse, A., M. Theristis and J. S. Stein (2021). “A New Photovoltaic Module Efficiency Model for Energy Prediction and Rating.” IEEE Journal of Photovoltaics 11(2): 527-534.
• Micheli, L., M. Theristis, A. Livera, J. S. Stein, G. E. Georghiou, M. Muller, F. Almonacid and E. F. Fernández (2021). “Improved PV Soiling Extraction Through the Detection of Cleanings and Change Points.” IEEE Journal of Photovoltaics 11(2): 519-526.
• M. Theristis, A. Livera, C. B. Jones, G. Makrides, G. E. Georghiou and J. S. Stein, “Nonlinear Photovoltaic Degradation Rates: Modeling and Comparison Against Conventional Methods,” in IEEE Journal of Photovoltaics, doi: 10.1109/JPHOTOV.2020.2992432.
• Driesse and Stein (2020) From IEC 61853 power measurements to PV system simulations (656 downloads) , SAND2020-3877
• Livera et al. (2020) Guidelines for ensuring data quality for photovoltaic system performance assessment and monitoring (544 downloads)
• Stein and Jordan (2018) Glass-Glass Photovoltaic Modules – Overview of Issues (1523 downloads) , Fall DuraMAT Workshop, Stanford, CA
• Stein et al. (2018) PV Lifetime Project: Measuring PV Module Performance Degradation: 2018 Indoor Flash Testing Results (2990 downloads) , WCPEC-7, Waikoloa, HI.
• Stein et al. (2018) PV Lifetime Project –Challenges of Measuring PV Module Degradation (927 downloads) , 2018 PV Module Reliability Workshop, Denver, CO
• Stein, J.S. (2017) Challenges of PV Degradation Analysis: PVLIB and Performance Data Analysis (917 downloads) , Fall DuraMAT Workshop, Albuquerque, NM
• Hansen and Jordan, (2017) Sample size guidelines for PV lifetime project (1471 downloads) , SAND2017-483R.

 

 

For more information about the PV Lifetime Project please contact the Task Lead for this project,  Marios Theristis (mtheris@sandia.gov)