What should you check on the technical data sheet for a photovoltaic roof element?

In an integrated system, separate documents may cover the covering, the active part and the electronics. You need them to be mutually compatible. High module power will not help if its version is not approved for the planned array. It is good practice for the document set to be attached to the quote and to remain available after installation.

At handover, compare the delivery markings with this set. This will help you catch a swapped variant before its connections are covered.

The overall dimension of the element is not always the effective covering dimension. Connections and overlaps may mean that more material surface is needed to cover the roof slope than its plan area suggests. With active parts, inactive areas are added as well. That is why you should not calculate power solely by multiplying the roof area.

Check whether the datasheet describes the permissible support spacing, weight and slope range. This information helps the designer assess the product’s application. It does not, however, replace verification of the building structure. Edge zones, local loads and details at windows, for which additional conditions may apply, are particularly important.

Rated power is one of the parameters. The designer also needs voltages, currents and coefficients describing how operation changes with temperature. The data are used to select the inverter, optimisers and connections. An element with similar power but a different voltage need not be a substitute in an existing roof.

It is worth asking what conditions were assumed for the measurement and whether the stated tolerance relates to a specific value. The owner does not have to design the circuits themselves. They should, however, understand that the declared power is not everyday production. An energy forecast also requires the conditions at the installation site and the properties of the entire installation.

Information about hail, wind or snow load testing is only useful together with the method and scope. The tested sample, the support method and the pass criterion matter. You must not combine the best figures from several different product versions into one roof description that no one has verified in that form.

The fire classification should be read in the same way. An assessment of how the covering behaves against external fire does not mean that all layers are non-combustible, nor does it mean the whole building has fire resistance. Ask what assembly the document covered and what conditions of its use need to be reproduced. The mere presence of the word ‘certificate’ does not settle this question.

If the catalogue, the instructions and the quote give different figures, ask for clarification before signing the order. It may be a product update, a different test method or a simple error. Choosing the more favourable figure yourself is risky. The contractor should indicate which documents apply to the given project.

For important parameters, it is best to obtain unambiguous confirmation in writing. This applies in particular to the possibility of installation on a specific pitch, the permissible solutions at the edges and the scope of the warranty. The clarification should refer to the assembly actually being ordered. A general answer about the whole product family may be insufficient.

Compare the same fields for each variant: the covering function, power, effective coverage, weight, conditions of use and the service approach. Then add the scope of supply and the cost of complete installation. This shows what follows from the properties of the material and what follows from the organisation of the order or design decisions.

The advantage of a well-described steel system is the ability to plan the active and passive parts as a single roof. The technical data sheet helps to check whether the chosen composition has the appropriate technical backup. Keep it in the as-built documentation. For a later repair, the designation of the correct variant may be more important than the name used in the advertisement.

Manufacturers and brands of solar roofs include Terrán, MDM NT (MyRoof), SunRoof, Megasol Energie, Wienerberger Wevolt, SolRoof, ML System, GAF Energy, Electrotile and Nelskamp.