We are frequently asked for advice on the best way to fit small photovoltaic solar panels, so in this article we will look at some basic solutions to what can sometimes by a difficult problem.
Many small solar panels (<30 Watts) are supplied with no fittings and often do not even have any holes in their frames (if fitted with a frame) which can be used. There are however many ways of attaching these panels safely and securely without damaging the solar panel or the surface to which it is attached.
Where a solar panel is supplied without fixing holes, it is typically quite difficult to add them at a later date (full details are supplied at the end of this article if you are interested). You do not want to be drilling through the panel itself, and even if the panel is fitted with an aluminium frame through which you could drill holes, you may not want to do risk damaging the frame permitting water ingress etc. The alternative is to use strong adhesives to stick panels in place, but this makes it more difficult to move/remove them at a later date.
One thing that should be remembered is that an air gap of at least 10mm should be left underneath the solar panel when fitted so that air can circulate free to help prevent overheating. As we showed in our article Effect of Temperature of Solar Panels a hot solar panel generates far less power than a cool solar panel.
Velcro Mounting Solar Panels
One of the best ways of economically fitting small solar panels is with velcro. Velcro strips of all shapes and sizes are available very cheaply – for example here: velcro strips. These strips are available in self-adhesive form, or without adhesive, but to ensure a strong bond a good weatherproof glue should be used in either case. Wooden battens can be fitted (screwed or glued) to the solar panel mounting location (e.g. shed/garage roof), velcro strips glued to them, and then the solar panels can be safely fixed in place.
Solar Panel Bonding Kits
For larger panels, or for panels to be fitted to moving vehicles (camper vans, boats etc) it is necessary to ensure that the solar panels are more securely and permanently affixed. Solar panel bonding kits – basically consisting of a very strong adhesive – are sold to enable panels to be glued (permanently) in place. These products are typically sold with a warning to glue the panel to rails or other raised fixtures rather than flush to the surface to prevent overheating.
Solar Panel Mounting Kits
A better solution than bonding kits is to use a universal solar panel mounting set. These are typically made up of four robust corners mounts which can be screwed or glued to the mounting location. The aluminium frame of the solar panel can then either be glued or screwed to the corner mounts. Such corner mounts raise the solar panel off the surface ensuring good air flow under it.
Drilling the Aluminium Frame of a Solar Panel
As pictured above, there are a wide range of alternative mountings which can be screwed into the aluminium frames typically supplied with 5+ Watt solar panels. In order to use these excellent mountings (some of the most secure and economical fittings) you may need to drill into the solar panel frame.
Drilling metals is not very easy so care should be taken. Ideally a variable speed drill should be used, but a standard drill can be used in short bursts of 5-10 seconds. Any longer and the drill bit will overheat (however this is not typically an issue with the thin aluminium of a solar panel frame). If using a hammer drill, turn off the hammer action or the vibrations could damage the frame, solar panel, and drill bit.
Mark the location of each hole to be drilled carefully, and then scribe two perpendicular lines which meet at the centre of the desired hole. Make an indentation with a centre-punch carefully at the crossing point of the two lines – this will stop the drill bit from sliding around when you start drilling. Using a good quality HSS drill bit – a Titanium Aluminium Nitride TiAIN coated bit is well worth the investment as it will last a long time and do a much better job than a standard HSS bit – drill out the hole. If you need a large hole due to the size of the fittings to be used, first drill out a small hole and then use a larger drill bit to make the desired size of hole. Use a file to remove any sharp edges from the drilled area as they can be very sharp.