The Solar PV Installation
This guide is intended to provide an introduction to the Solar PV installation process. The example below refers to a commercial installation but the method can be applied to any domestic or commercial property. A sheet metal/corrugated roof installation will be somewhat different in fixing to those of tile or slate, but the general steps will be the same. We can also develop bespoke mounting systems for a ground mounted system or to fit a flat roof.
For finished examples and more photos of our engineers at work, have a look at our Case Studies.
Not all installations will require scaffolding. Where it does we work alongside a reputable local scaffolding team. Depending on the expected length of the job we will arrange for the erection of scaffolding either before or during the morning of the first working day. The cost of the scaffold will be included in our installation quote (except in unusual circumstances).
Scaffolding will be erected to reach the eaves of the roof and ensures the safety of those working on the roof with compliance to all relevant Health and Safety codes. In some cases additional safety measures such as netting will also be required and again, the cost of complying with the safety needs on site will be incorporated into our quote.
Positioning the Roof Anchors
Measurements taken during the site survey of your property are checked and small chalk marks made on the roof to indicate the planned positions of the panels. The chalk washes off the next time it rains.
It is important that the roof anchors are positioned carefully on the roof to ensure the solar panels can be installed correctly. The location of the rafters under the existing roof tiles are identified. The anchors are then placed on top of the tiles where they will eventually be positioned while measurements are taken to ensure that the aluminium frame will sit ‘straight’.
Once the position of the anchors is determined they can be fixed to the roof. One roof tile is removed to allow the anchor to be screwed to the rafter and then replaced to ensure the roof remains water tight. It is important that the correct type of anchor is used. This will be determined during the site survey.
If the length of the frame is longer than the aluminium bars supplied then they are spliced together using specially designed strips of aluminium and further bolts.
Attaching the Frame
Once all the roof anchors are fixed into place, the aluminium bars that make up the frame are then locked into the anchors and screwed into place. Each bar is checked to make sure that it is straight and that all the bars are parallel to each other. This is the single most important step in ensuring that the panels will look correct.
Installing the PV Panels
With the bars in place, the frame is complete and the panels can be attached and clamped to the frame. A minimum of 4 clamps is used per solar panel, though in some cases extra clamps are used to aid the parallel alignment of the rows.
The panels are either placed by row or by column depending upon which is the best in each specific situation. In the photo to the right the panels are being placed by row. In this case the top row is placed and the alignment of each row thereafter is taken from it.
Wiring the Panels
Panels are wired by the manufacturer, meaning the rooftop connection is straightforward. The specific voltage, amperage and power of the system determine how the panels are connected. Smaller systems connect a single series to a single inverter, while larger systems connect several parallel series into a single inverter. Even larger systems may require multiple series into multiple inverters. Shading and panel positioning can also influence the design of the wiring.
Installing the final PV Panel
Once the top row of solar panels is correctly clamped, the rows beneath are secured to the frame in the same manner, taking their positioning from the row above.
Aligning the panels parallel to the row above is extremely important in ensuring the finished system will look good. This process is made easier if the original frame is well placed, which is why our installers take care to get things right within the initial stages of the installation.
Once all the panels have been installed and the alignment checked the final wiring of the system can begin. The DC wiring from the panels on the roof needs to enter the property in order to be connected to the electrics in your home. In some cases this is achieved by running the wire under the eaves and directly into the loft. In others, such as in the image on the right, a hole is made within the wall which is then sealed to ensure it is watertight.
The system are finally fully commissioned by one of our qualified electrical engineers, who check over every aspect of installation by completing AC and DC tests to ensure the system is working correctly.
Data is then relayed to the office where the system will be registered with the MCS for all systems below 50kW. Alternatively with Ofgem for all systems larger than 50kW.
Once this is completed you will be eligible to start receiving for your Fit Payments.
The Duncan’s team will be avaliable to assist throughout the application process and to help complete all necessary paperwork, and answer any of questions that are brought up.