This paper draws 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−yrforprojectsbuiltin2007toanaverageof17/kWDC-yr in 2019. Across 13 sources, the range in average lifetime OpEx for projects built in 2019 is broad, from 13to25/kWDC-yr. Operations and maintenance (O&M) costs—one component of OpEx—have declined precipitously in recent years, to 5−8/kWDC−yrinmanycases.Propertytaxesandlandleasecostsarehighlyvariableacrosssites,butonaverageare—together—ofsimilarmagnitude.OtherOpExlineitemsincludesecurity,insurance,andassetmanagement.Given2007−2009valuesfornotonlyprojectlifeandOpExbutalsootherdriversofthelevelizedcostofenergy(LCOE,excludingtheinvestmenttaxcredit),theLCOEforutility−scalePVprojectsbuiltfrom2007through2009averaged305/MWh. Using 2019 values for all parameters yields an average LCOE of 51/MWh.ThedeclineinLCOEfrom305/MWh to 51/MWhwaspredominantlycausedbyreductionsinup−frontexpenditures(and,toamuchlesserextent,bychangesincapacityfactors,financingcosts,andtaxrates),but922/MWh) of the overall decline is due to improvements in project life and OpEx. Project life extensions and OpEx reductions have had similarly sized impacts on LCOE over this period, at 11/MWheach.HadprojectlifeandOpExnotimprovedoverthelastdecade,LCOEin2019wouldhaveinsteadbeen73/MWh—43% higher.
Given the limited quantity and comparability of previously available data on these cost drivers, the data and trends presented here may inform assumptions used by electric system planners, modelers, and analysts. The results may also provide useful benchmarks to the solar industry, helping developers and assets owners compare their expectations for project life and OpEx with those of their peers