Every day people ring our consultants and want to know about which panels and inverters are best. They are very concerned about cell and module efficiency, panel warranty, inverter reliability and a myriad of other technical features. Nobody ever rings us about whether the Clenergy Kliplok footings are NATA certified (they are) or what type of dc isolators we use and why. We never get asked about the UV rating of conduit or whether the cable size we use will address voltage rise (it will). It just never happens.
But it should.
The Balance of System equipment is what makes a system. Anyone can buy a good inverter and some good panels but piecing it all together safely and to the standards with gear that will outlive the panels and inverter takes experience and attention to detail. It adds to the initial purchase price of the system but ensures your investment will stand the test of time. which ultimately saves you money. The main components of the Balance of System are:
- Panel mounting Equipment
- Conduit and cable tray
- Switchboard work
If you have a quote with good panels and inverter but seems too cheap, they are cutting the cost of the BoS and the installation itself. More often than not this results in a failed system.
Panel Mounting Equipment
This includes the rails, the footings, the fasteners, end and mid clamps. This gear holds the array together and prevents it blowing off the roof or tearing a roof up. On Colourbond or tile roofs footings are screwed directly to the roof structure making a very secure attachment. On Kliplok type roofs, rails are connected via feet that clamp to the profile of the Kliplok. This is less secure and extreme care must be taken to ensure that the correct feet for the profile are used. For this reason Envirogroup choose Clenergy.
As well as providing us with the best mounting system available, Clenergy offer design consultancy and structural engineering certification if we need it. Most Clenergy products satisfy with certification the requirements of Australian structural engineers, a now mandatory component of larger commercial systems.
DC Isolators, particularly those mounted on the roof, are the most contentious part of the system. Cheap isolators can burn and destroy a system or even a building so they are not a component that should be dumbed down. Do not go cheap on these! There are enough good isolators available to not have to make this mistake. Basically, the isolator’s job is to shut down the dc component of the system which is the array. There are two, one on the roof and another near the inverter/switchboard. Inverters like SMA and Fronius have a built-in dc isolator so you don’t need to buy that one. We choose ZJ Beny because they are IP66 rated, UV protected and have an arc time less than 3ms so they are built to survive.