Technical Evaluation and Repowering

In July 2017 the operator of this PV-plant contracted greentech with an independent technical inspection to optimize the plant’s performance. When greentech O&M services took control of this solar farm the site was underperforming and not meeting its Performance Ratio or Technical Availability obligations. The performance ratio as well as the technical availability of the PV-plant were clearly below the expected values. By providing daily monitoring analysis and detailed reporting to the asset engineers on site who rapidly responded to inverter faults, we have been able to get this site’s performance ratio back into contractual obligations.

Restoration of the communication

At the start of greentech’s O&M services for the solar farm significant amounts of the inverters on site were not communicating or showing significant underperformance. The first step of repowering the site was to restore the communication system and re-integrate the inverters into the plant communication:

  • Restoration of communication with all inverters of the PV-plant
  • Reprogramming of IP addresses
  • Repair and replacement of communication cables
  • Reconfiguration of the data logger

Repowering measures

After all inverters were communicating again, we carried out a detailed performance analysis to determine which of the inverters had an underperformance of 5% or more. Once this analysis was completed, the asset engineers carried out an indepth analysis and Repowering:

  • Testing of all effected strings
  • identification of root cause (string cables or inverters)
  • repair or exchange of effected string cables
  • Exchange of faulty inverters within warranty process
  • Assurance of warranty claims of the client

Increase of average Performance Ratio to > 3 % %

In addition to cable and inverter replacements, greentech also carried out a thermographic analysis of the modules to identify modules which showed hotspots or were inactive in general. Finally, a professional module cleaning was applied to help maximise the production, while the site continued to come back to full production capacity.

After carrying out the corrective maintenance actions, the site is now producing with an average PR of more than 3 % above the PR before greentech started its O&M mandate. As a result of the increased PR, the client is now no longer being issued penalty fees for under performance. greentech remains vigilant to keep this site on track and support it in making up for some of the previously lost performance.

*Calculation based on 10 month time period since start of the mandate from july 2017 – April 2018 compared to July 2016 – April 2017.
Technical evaluation and repowering