A recent study has shown that missing Supervisory Control and Data Acquisition (SCADA) data could be distorting measured solar tracker availability in utility-scale projects. Larger distortions in tracker availability data could also affect perceptions of the overall project’s performance.

The findings were published in a research paper titled ‘Assessing tracker availability in 2 GW solar power plants,’ and published in the EPJ Photovoltaics journal.

The research paper found that while a tracker can increase the energy yield of solar projects by 20-35%, a significant portion of missing data could be masking the tracker’s true operational efficiency.

The researchers analyzed data sets from 64 solar power projects with single-axis trackers, mostly installed in Mediterranean and temperate climate regions, and attempted to estimate the trackers’ availability periods.  Of the 64 projects, 15 were found to have insufficient data quality for analysis. Hence, a dataset of 49 projects was considered for this research.

Tracker availability accounts for the time during which the tracker was operational, independent of its impact on energy generation.

The data on tracker availability was compiled based on the core track, which covers the period when all trackers behave consistently, and on the All Track, which compiles a tracker’s complete day of operations, including backtracking behavior.

Under All Track, tracker availability ranged from 96% to 22%. However, trackers showed 85-90% availability under Core Track, showcasing trackers’ inability to perform backtracking.

The research found that the missing data was due to communication gaps, where data is not collected, or stalled or frozen data being retrieved in the SCADA system. The researchers said it could also be attributed to poor system sizing and significant signal interference within the project.

Up to 15% of data on trackers was missing in most solar projects. The missing data ranged from 0.5% to 70%.

However, the research found that the availability of trackers in most solar projects remained far lower than the contractual availability of most equipment attached to the solar system and communicating to the SCADA, i.e., 99%.

The research concluded that as the industry becomes more competitive, and a key contributor to the energy mix in many countries, solar project developers will require accurate information on equipment availability to feed into simulation models and contractual guarantees.

It stressed the need for better data quality to optimize energy generation from solar projects.

Last year, Andrew Warden, Founder and CEO at GameChange Solar, highlighted that trackers have found wider acceptance in utility-scale projects, but India’s varying geographical challenges require customized solutions for the impacting weather conditions.