The majority of solar PV panels are fitted with aluminum frames, which hugs the glass covering the top and the solar backsheet at the bottom.
Why is the solar panel frame important?
The solar panel frame plays a fundamental role. On the one hand, it protects the internal components from thermal and mechanical tensions while on the contrary, it provides mounting attachment points.
Besides, framed solar PV panels offer better protected during transport than frameless solar panels.
The properties of a high-quality solar panel frame
Anodized aluminum is considered to be superior material from which solar panel frames can be constructed. Coated solar panel frames are much more likely to sustain scratches or damage but are more expensive too.
Anodizing of solar Panel Frames (Source: http://hentecindustry.com/)
Solar panel frames which have closed in cavities are ones to avoid. These could collect water, which once frozen, may expand and cause deformation of the solar panel frame or even cause it to break.
A flat tapered edge where the solar panel frame meets the glass/cells will reduce shading and will allow water to run off, and frost is unable to build up in the winter. Frost can cause damage such as the separation of the frame from the solar PV panel.
Tapered edges will also prevent the accumulation of dust, pollen or other soils which can facilitate the growth of moss. If moss or lichen covers part of the solar PV panels, it can affect the efficiency of the solar output.
It important to insure that the solar panel frame does not have any sharp edges and should be screwed together with special screws designed for this particular job. This guarantees that the solar panel frame is electrically and mechanically conductive and earthed throughout.
Solar panel frame parts should be stuck firmly to the laminate. This can be done mechanically on the inside edges of the backside of the solar panel frame.
The materials used to join the aluminum and glass together are important to avoid stress build up because the expansion and contraction ratio of the two parts of the solar panel are different.
The manufacturers tend to cut costs when finding the right compromise between the design and weight of aluminum to ensure reliable mechanical properties.
Is solar panel frames important?
As mentioned above, solar panel frames offer many advantages. However, a good frameless solar module can be robust enough to withstand any heavy weather or other impacts. This relates to the strength and thickness of the glass.
However, it is usual that the manufacturers decrease costs by using slightly thinner glass. The average thickness of the glass of a framed solar PV panels is around 3 to 3.5mm. For frameless PV modules, it is around 4mm.
Frameless solar PV panels weigh less and are therefore lighter to handle for the solar installer.
Frameless solar panel (Source: http://www.trinasolar.com)
Some tips for choosing a high-quality solar panel frame
- Anodized Aluminum with clear coating increases the corrosion-resistance.
- High tensile strength to enhance snow load resistance, wind impact, (Solar panel certifications: UL1703, IEC61215, and IEC61730)
- Matching frame color with that of the racks and clips (Black solar panel frames are more expensive than the silver).
- The solar panel frame should be able to combine with many PV mounting systems.
- Look very closely and observe the type and integrity of the materials used to bond the frame to the glass laminate
- Thinner anodized Aluminum frames are good for roof statics as well as being slightly lighter to handle for the installer.