Careful preparation and planning must be undertaken by an installer before a solar PV panel system can be fitted onto an average domestic householder’s rooftop. Most general advice tends to focus on issues such as type of silicon cell panels, power rating to meet the household annual requirement and to also consistently generate sufficient electricity, roof direction and pitch, shading from nearby buildings and trees, etc.
The above mentioned items are indeed, absolutely vital to ensure the selected photovoltaics system is specified and fitted correctly to obtain maximum benefit. However, there are a number of other practical installation issues and potential problems to be addressed before an array may be allowed to be physically attached to a rooftop surface.
Installers of solar panel technology must have fully completed and qualified on approved and nationally recognised City & Guilds /BPEC/NICEIC solar PV courses or solar courses, verified up to mandatory levels 2 and 3.
In other words, legitimately competent to carry out the work to the required legal Building Regulations and Health & Safety standards. It should be noted that approved training qualifications are a compulsory requirement for eligibility to register as a genuine, competent and approved MSC installer of MSC approved solar PV systems.
With the recent news that false or misleading information has been used to persuade unwary householders to purchase solar PV systems, it is crucial that the professional industry ensures the ‘rogue trader’ element does not undermine consumer confidence and hinder the growing marketplace.
The first consideration is that a solar panel is heavy and in some instances requires two installers to physically carry and handle the fitting without incident. With a typical weight of around 20 kg, the attachment of a panel array of up to 2kWp can add around 300Kg or nearly half a metric tonne to the roof structure of an average domestic property when factoring in the weight of the mounting kit.
When inspecting the roof for statutory load bearing capability, there are likely to be some occasions when the roof load will be increased above the 15 per cent threshold for an individual roof design specification, and a structural survey will be required.
The next consideration has to be the 25 year longevity of the FeedInTariff Scheme (FiTs). The question has to asked at the outset whether the present condition of the roof is adequate for the entire 25 year period of the scheme or will renovation or maintenance definitely be required at some stage after the panels have been fitted.
The condition of the proposed roof structure naturally ties in with an assessment of the type of roofing materials themselves, that are currently in place. Some roof material categories are simply not suitable for either load bearing or taking fixings due to roof sheets cracking, prevention of condensation and thermal expansion.
PART TWO will look at some more of the actual problems that roofer installers can encounter when fitting a PV system to a rooftop.