UCC 40kW PV System O’Rathilly Building

Case Study

PV Generation won the contract to supply, design, install and commission a 40kWp PV system on the O’Rathilly building in UCC.

Design Process

The type of PV modules and the brand of inverter were specified prior to site survey during the tendering stage of the project.

The design process began with a site survey. Detailed roof measurements were taken and any roof obstacles were noted, along with length of cable runs, tie in locations and building heights.

With this information a wind loading analysis was completed on the Van der Valk mounting equipment design software.

This report generated a Bill of materials required to install the PV modules, a ballast calculation schedule and also generate a simulation of the forces the roof would be exposed to.

This wind loading  report was reviewed by a third party consultant engineering firm and signed off that it was safe to proceed with the PV installation. 

The next step in the design process was to configure the string layout in the inverters.

This was completed with the Fronius configuration software.

This generated a report and provided a schedule of the string layout.

With this information a detailed layout and string configuration drawing could be drafted to be supplied to the install team.

A string sizing calculation was also completed specifying the cables that would keep the DC voltage drop below 1% voltage drop and the AC voltage drop below 1%.

All electrical components minimum ratings were specified to the following formula:

Voltage: Voc(stc) x 1.15

Current: Isc(stc) x 1.25

With this information a detailed single line diagram could also be drafted and supplied to the install team.

Project Implementation

All material was delivered and craned to the installation area out of hours to minimize disruption to the client and also to minimize any health and safety issues to the users of the campus.

The roofing crew and electrical crew worked in parallel with a team lead appointed for both crews there was also an overall site foreman on site to ensure works were completed to a high standard and that site safety and methodology were followed. 

The electrical crew contained three qualified electricians and two apprentices.

The roofing crew contained three qualified carpenters and two labourers.

Prior to any works commencing daily a JSSWP would be completed and any safety issues would be mitigated, escalated to management or the client and made safe.

UCC would also issue a permit to work prior to works commencing.

The electrical crew were split into two teams.

One team were installing the cable containment and pulling the cables while the other team mounted the electrical components to the wall and terminated the cables.

One electrician assisted with the DC string layout on the roof.

The roofing crew also worked in teams. One team assembling the mounting frame and the other team placing the mounting frame on the roof one team fitting the ballast and PV modules.

All roof works were completed within three working days and electrical works were completed within five working days.

The PSCS completed a snag list and all snags were rectified the following day.


Once all works were completed the electrical foreman and the engineer completed the commissioning procedure.

The strings were all tested as per guidance of the MCS solar pv document and all values were recorded on the commissioning cert.

The inverters were than commissioned as per the manufacturers’ guidelines and the grid settings were set to the Irish settings. All electrical components were also tested to be functioning correctly.

The G10 panel was than commissioned and witness tested in the presence of an ESB personell.

PSDP/PSCS Fulfilment

PSDS was completed in house by PV Generation.

PSCS was fulfilled by Keirnans Engineering who had oversight on the installation of the PV system.


Since installation was completed the system has been performing with a higher output then the estimates at design stage.

The installation was completed within budget and on schedule.

Lessons learnt

The timeline for the NC5 grid connection application was very ambitious.

Going forward a longer lead time will be allocated to the grid connection application.

When ordering a G10 panel the service of commissioning and witness testing of the panel from the panel manufacturer must be included in the same order in future projects.

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Whatever your query, whether its regarding the suitability of your roof for Solar PV panels or how much you can save with IR heaters or even how much does it cost to get your own EV car charger installed at home, we’re here to help! Simply contact one of our experts today.

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047 79078


PV Generation Ltd, Unit 5 Block F, Brooklodge Business Park, Glanmire, Cork, T45 RC78

PV Generation Ltd, Scotstown Business Centre, Scotstown, Co. Monaghan, H18 FH36

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