Technical Assessments and Photovoltaic Systems: the Power's On !
The first Technical Assessment (ATec) has just been issued for a photovoltaic (PV) panel made up of electricity generation modules (300 – 350 Wc) associated with an assembly system. “The ATec was issued for a period of three years”, states Céline Mehl, engineer at CSTB. “It covers not only the system as such, but also its implementation, as well as its characteristics concerning electricity generation and electrical safety.” As the alternating current and inverter part is the subject of known frames of reference, it is not included in the ATec.
The issuance of this ATec goes hand in hand with the creation of a Specialized Group – the GS 21 “Photovoltaic Systems” – responsible for formulating these ATecs. It is composed of recognized experts in fields as diverse as photovoltaics, electricity, roofing, and glazing, etc. From a practical standpoint, GS 21 has drawn up a help document for drafting the Technical File to be provided by the manufacturers involved in such an initiative. They will also be required to systematically produce set-up instructions in French for the system, and they may, as much as possible, provide GS21 with mock-ups, videos, or photos to enable it to view the singular points of the system. This will facilitate the studies to conduct, as much in terms of expertise as optimization of time periods for awarding the ATec.
Prerequisites to comply with
On principle, all innovative products – and, thus, those relating to PV – are intended to fall within the framework of an initiative resulting in the issuance of a Technical Assessment. While several standards were already in place for PV systems (NF EN 61215, NF EN 61646, etc.), until now, no document on technical specifications for use and implementation (whether it be in apposition or incorporation in building envelope) was available. The work carried out by CSTB, and resulting in the establishment of an evaluation procedure, puts an end to this gap. “However, before starting to process a file, the applicant must comply with a certain number of prerequisites”, explains Céline Mehl. “They concern compliance with standards NF EN 61215 and NF EN 61646 characterizing the electrical performances of the photovoltaic module and the evaluation of its durability in conditions of accelerated ageing. In addition, products submitted for evaluation will be required to meet other safety requirements. In particular, this involves those relating to electrical safety class II on electrical equipment or concerning photovoltaic installation compliance in terms of specific technical guides and Standards.”
Specific analyses depending on the modules
The characterization of the PV module is at the heart of the evaluation procedure. For each type of module – and depending on its implementation – there are specific corresponding requirements. Generally speaking, standard modules (glass/polymer) will only be required to meet the obligatory prerequisites mentioned previously, except for certain specific configurations: for example, for façade, glass roof or shade screen applications with no rear protection for which the durability, strength and safety of the assembly must be tested. In the event the photovoltaic systems are similar to known building systems (glass products, waterproof membranes, etc.), they will be asked for equivalent minimum performances and behaviour in terms of the frames of reference concerned. In addition, CSTB will conduct further studies or specific analyses to evaluate the overall behaviour of the system, taking into account the specificities related to the presence of a photovoltaic component.
“Each Technical File submitted for evaluation is unique”, explains Céline Mehl. “It is difficult to be able to determine in advance all of the justifications that each PV system must meet. This is especially true for requirements related to its implementation.” While studies are conducted on a case-by-case basis, the durability of materials, resistance to climatic stress, water-tightness and air-tightness, and life safety, etc., are among the “essentials” that must be checked. So, CSTB possesses all the benches needed to conduct tests.
EvalIE, one-stop shop for the evaluation of HVAC systems
Whether it is for new construction or retrofitting, the creation of low-consumption buildings (50 kWh/m2/year) as established by the Grenelle de l’Environnement is moving in an essential manner through very strong development in energy systems. In order to meet the expectations of manufacturers, specifiers, entrepreneurs and insurance companies (ten-year warranty), CSTB proposes a one-stop shop to evaluate products, such as photovoltaic systems. The EvalIE (Evaluation of HVAC systems) team, based in Sophia Antipolis and Champs-sur-Marne, is responsible for this mission of examining Technical Assessment files.
Contact : nadege.blanchard(at)cstb.fr
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