Original Article

Assessing tracker availability in 2 GW solar power plants

¹ Statkraft UK LTD, 19th Floor 22 Bishopsgate, London EC2N 4BQ, UK
² 3E, Kalkkaai 6 Quai à la Chaux, Brussels 1000, Belgium

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Received: 30 June 2025
Accepted: 1 December 2025
Published online: 16 January 2026

Abstract

Single-axis trackers are key components to optimize utility-scale solar energy generation. As the overall electricity production share of PV is globally increasing at a significant pace, profitability margins narrowed and the industry is becoming more competitive. Ensuring high availability of all devices in a photovoltaic (PV) power plant is crucial for healthy asset life. Historically, specific key performance indicators (KPI) for single-axis trackers have been overlooked by both research and industry. This work proposes a KPI for trackers, with two alternative methods. Over 2GWp of PV power plants have been analyzed, mostly located in temperate climate zones. The median of results range from 66% to 88% availability, depending on data filtering considerations. These results are substantial, and alarming. Industry claims sometimes even as high as 99% availability, while the assessment of more than 2 GWp PV power plants tells us a different story. In addition, this work highlights and discusses multiple issues regarding tracker data quality, especially related to angle datasets, and identifies missing data as one of the main systematic issues when dealing with single-axis tracker data.