Solar Roofing – Flat and Metal Roofs with Integrated Solar …

In this article we will discuss solar roofing systems, which integrate roofing materials with solar PV panels or solar thermal systems. Specifically we will cover, metal roofs, PVC flat roofing membranes and asphalt shingles. Although most roof-mounted solar systems are installed on top of an existing roof be it an asphalt shingles roof or any type of flat roof these solar systems are not integrated into the roofing material, and therefore are not solar roofs.

Most solar systems are installed on a roof of a house or a building. The exception are solar farms or ground-mounted solar installations, but these are rare, and are usually 100% commercial solar systems. There are a number of reasons why most solar systems are installed on roofs. The primary one being limited space especially in an urban setting, where roofs represent significant unused space. Another reason is that usually roofs are not shaded by trees, nearby buildings, etc they are the highest point of a building with great sun exposure, which makes them perfect to install solar panels on.

Solar roofing is a final product, which integrates solar panels with the roofing material suitable for either a sloped or a flat roof. The solar panels used in solar roofing are usually thin-film photovoltaic laminates. Most popular Solar PV laminates commercially used today, are the Unisolar thin-film PV panels.

Unisolar thin-film PV laminates were originally designed to fit into and be integrated with standing seam metal roof panels. Unisolar panels are 15.5 inches wide and fit perfectly into a 16 standing seam panels, and are attached or laminated with special butyl adhesive that is on the back of each Uni-solar PV panel.

However, unlike with metal roofs, solar integrators were having flat roof leak repair issues with solar systems they installed on flat commercial roofs. After they installed solar mounting racks and attached them to the roof deck, the fasteners would start leaking after a while.

Roofing manufacturers adressed this issue with different versions of flat roofing materials that integrated Unisolar PV panels one such system is IB Solar Roof. There are many types of both solar metal roofs and solar flat roofs, using solar PV panels from various manufacturers (though as I said, most do use Unisolar PV laminates).

The most common type of solar metal roofing is the standing seam metal roof with integrated Unisolar PV laminates. Unisolar PV laminates were initially designed to fit in the pan of standing seam panels, with the connection terminals concealed by the ridge cap. Because the connectors or terminals of these PV panels are not UV stable, they need to be hidden from the sun, while the rest of the panel is of course exposed to the sun to generate solar electricity.

The benefits of standing seam solar metal roofing include fast installation, easy troubleshooting, and lifetime leak free roof performance. Additionally, in the US, you can get the 30% solar tax credit for installing a metal roof, as it is a part of the solar system.

Another type of solar metal roofing would be solar metal shingles. The concept is similar to solar standing seam roofing, but since metal shingles are much smaller, the solar PV laminates have to be adjusted to the size of the shingle. Also, all the terminals must be connected during the installation if you miss just one, the circle will be broken and the solar system will not work. Imagine finding the broken link when you have hundreds if not thousands of metal shingles to take off to find one broken connection!

Price-wise, I think that standing seam solar metal roofing is much more viable, as there is substantially less installation labor involved and much less potential troubleshooting, if something goes wrong. Imagine hiring a solar integrator and a professional metal roofer at $75-100 per hour each to find what is wrong with your solar metal shingles roof. Even if everything is peachy, the amount of time that will be used to install solar metal shingles is much more than that of a solar standing seam roof. The total solar system price will be significantly higher just from all that extra labor.

More here:
Solar Roofing - Flat and Metal Roofs with Integrated Solar ...