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