PV Lifetime Project

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 will be supplemented with regular testing under repeatable test conditions indoors. The focus will be on the PV module, as well as other hardware components (junction boxes, bypass diodes, and module-level electronics) attached to it. Hardware will be 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 will be continuously monitored for DC current and voltage, as well as periodic I-V curves at the string level. In the future, once degradation trends have been identified with more certainty, results will be made available to the public online. This data is expected to enable 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.
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

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

Publications

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