Solar power is generated by converting sunlight or heat into energy either directly using photovoltaic cells or indirectly using concentrated solar power (CSP) in which concentrated solar power systems use mirrors or tracking systems to focus a huge area of sunlight into a small beam. Sunlight is converted into electricity using photovoltaic effect.
Although ‘solar shingles’ offer excellent incentives besides a number of benefits compared to conventional solar cells, there are certain typical challenges inbuilt in the installation of such a roof. One should plan meticulously and in particular considerable attention is needed when wiring solar shingles. Solar shingles, also known as photovoltaic shingles appear similar to traditional asphalt shingles or tiles and are available in various types.
Here are detailed guidelines explaining the installation process of a photovoltaic solar shingle roof. Solar shingles present superior artistic look in contrast to traditional solar panels and in addition, it is less complex accessory to the home. Unlike solar panels, which need a ‘mounting rack’ for installing above the roof; solar shingles are fastened directly on top of the roof.
From the cost perspective, one has to add only the difference in price between normal roofing shingles and solar shingles to the cost and compensating the additional cost, there will be sizeable saving on the cost of mounting racks. A very systematic planning is needed before taking up the work of installation of the solar roof.
The layout of the roof, the number of tiles needed to generate the required amount of power and how the internal wiring though the house linking it to the power control panel and inverter will be carried out are some of the aspects that need careful assessment.
Solar cells should be interconnected in series in order to supply high voltage to the inverter. In this configuration, the positive terminal of each element is wired to the negative terminal of the next as against parallel wiring in which each element is kept on a different branch of the same wire.
In a serial wiring, the voltages of each element adds up. For installation of solar shingles on the roof, they should be clipped together and placed on top of each other as is done in respect of usual roofing shingles. When fixing standard shingles this one step alone would be sufficient.
However, in case of photovoltaic shingles, it is also necessary to connect with electric wires. A standard assembly involves drilling holes through the roof every 3 ½ inches along a line of superimposed tiles in order to pass the wires through the holes. It is better to use a template and mark the places where each hole is to be drilled, prior to the actual installation of shingles, to avoid any errors.
After passing wires through the holes drilled for wiring, channel each line of wires through a ‘wiring raceway’. Proper alignment of ‘wiring holes’ and raceways between structural components in the roof is very essential. It is necessary to engage a licensed electrician to complete the work of wiring of solar cells to the inverter and power control unit and from the inverter to the electric power grid. It is also very important to take into account that solar shingles cannot be cut, as this will make solar cells ineffective.
Additionally, a minimum slope of 3: 12 of the roof is needed to ensure smooth drainage. While installation of a solar shingle roof will confer great incentives, the installation job is not easy. For correct installation, appropriate planning and great care at each stage of the process is absolutely essential. It is not a job that can be undertaken in a hurry.