Abstract
This paper describes how performance problems can be “masked,” or not readily evident by several causes: by photovoltaic (PV) system configuration (such as the size of the PV array capacity relative to the size of the inverter and the resultant clipped operating mode); by instrumentation design, installation, and maintenance (such as a misaligned or dirty pyranometer); by contract clauses (when operational availability is transformed to contractual availability, which excludes many factors); and by identified management and operational practices (such as reporting on a portfolio of plants rather than individually). A simple method based on a duration curve is introduced to overcome shortcomings of Performance Ratio based on nameplate capacity and Performance Index based on hourly simulation when quantifying masking effects, and inverter clipping and pyranometer soiling are presented as two examples of the new method. With a better understanding of the non-transparency of masking issues, stakeholders can better interpret performance data and deliver improved AC and DC plant conditions through PV system operation and maintenance (O&M) for improved performance, reduced O&M costs, and a more consistently delivered, and reduced, levelized cost of energy (LCOE).
Original language | American English |
---|---|
Article number | 111067 |
Number of pages | 8 |
Journal | Renewable and Sustainable Energy Reviews |
Volume | 145 |
DOIs | |
State | Published - Jul 2021 |
Bibliographical note
Publisher Copyright:© 2021 Elsevier Ltd
NREL Publication Number
- NREL/JA-5C00-76012
Keywords
- AC/DC ratio
- Availability
- Inverter clipping
- Inverter saturation
- Masking
- Operation and maintenance (O&M)
- Performance ratio
- Photovoltaic system performance