Lawrence Berkeley National Laboratory has published an interesting paper based on a survey of solar industry professionals and other sources to clarify trends in the expected useful life and operational expenditure (OpEx) of utility-scale photovoltaic (PV) plants in the United States.

Solar project developers, sponsors, long-term owners, and consultants have increased project-life assumptions over time, from an average of ~21.5 years in 2007 to ~32.5 years in 2019. Current assumptions range from 25 years to more than 35 years depending on the organization; 17 out of 19 organizations surveyed or reviewed use 30 years or more.

Levelized, lifetime OpEx estimates have declined from an average of ~$35/kWDC-yr for projects built in 2007 to an average of ~$17/kWDC-yr in 2019. Across 13 sources, the range in average lifetime OpEx for projects built in 2019 is broad, from $13 to $25/kWDC-yr. Operations and maintenance (O&M) costs—one component of OpEx—have declined precipitously in recent years, to $5-8/kWDC-yr in many cases. Property taxes and land lease costs are highly variable across sites, but on average are—together—of similar magnitude. Other OpEx line items include security, insurance, and asset management.

The paper is available at: https://eta-publications.lbl.gov/sites/default/files/solar_life_and_opex_report.pdf