Although only a handful of Australian builders offer solar energy systems, the residential solar market has boomed over the past five years. Technology has improved exponentially while installation costs have substantially decreased, helped by government incentives and rebates. By many accounts, this could be the year home builders start paying attention.
- Is the roofing system compatible?
- Which mounting system are you using?
- How will the solar power installation affect the build process?
- Will the warranty of the solar power system affect the builder's warranty?
- Who is installing the solar panels?
So, if you have decided to provide solar-ready roofing systems, you must take many precautions in your design package.
Consider safety issues associated with solar installations:
If these questions are not addressed before the installation, the probability of a roof failure and subsequent water damage is extremely high.
We aim to help builders protect their investment by providing the information you need to address the factors involved in installing roof-mounted solar panels.
CHECK THE COMPATIBILITY OF THE ROOFING SYSTEM WITH THE SOLAR
Low Slope Roofs
Water leaks; or premature failures with these types of roof systems are often caused by the following poor workmanship or using the incorrect products for the roofing system.
It's important to understand that modern low slope roof products are not designed to be penetrated after their initial installation, nor were they designed to withstand prolonged exposure to a heat source.
Most pitched roof systems are either steel or concrete/terracotta roof tile. (Solar panels require routine maintenance, and consideration should be made to the location of the solar panels to ensure easy maintenance).
What Mounting System are You Using?
There are four different types of mounting systems available: Ballast, Adhered, Penetrating and Mechanical. The proper selection will depend on the roof type.
1) Ballast System: Ballast systems use dead weight to hold the solar panel racks on the roof– so no drilling or penetrating of the roof materials is required for its installation. However, one of the drawbacks of a ballast system is that the roof ballasts are large, and in areas subject to heavy rain or snow events, the stormwater can back up behind the ballast. This will create a dam effect which may cause water damage to the structure following a rain event. When designing a ballasted solar power system, it is important to consider water flow, maintenance, photovoltaic design and static loads on the structure.
2) Adhered Panel: Adhered panels are a great option. However, their initial investment cost often makes them prohibitive for installation. One of the main advantages of adhered panels over the traditional rack-mounted system is that the solar panels are glued on to the roof. These are special frameless, flexible solar modules, and the mounting system is custom designed for the application.
3) Penetrating Fastener: As its name states, the system uses roof penetrations to secure the system. This is the most common mounting method used for solar panel installations. Existing roof screws are removed and new ones installed with tin feet to hold the rail; therefore, no new holes are required. On tile roofs, the bracket is installed to the roof truss or rafter, and the roof tile is ground out to ensure the roof tile sits level and does not cause water ingress.
This method is used for the roof sheets such as Kliplock, Longline etc. Non-penetrative feet are used to install the mounting frames on the roof. No penetration is required except the one for cable entries.
Considering Health and Safety Risks Associated with Solar Installations:
Even if the solar power system is turned off, solar panels still generate voltage; therefore, the D.C. cables on the roof are still energised. This can create an electric shock hazard for installers, people who maintain the system or, in the event of a fire, first responders. Only qualified persons must be used when installing, altering or maintaining a solar power system.
The system must be installed using high-quality materials (i.e. D.C. Isolators, conduits, glands etc.) to prevent water ingress and potential fires.
The Future of Solar Panels
Regarding the next generation of solar panel systems, Leeson Group is the largest installer nationally of BIPV. Also, it has a new solar tile in the final stages of development that will be released in 2022. These solar tiles sit like a roof tile alongside standard roof tiles to establish a clean aesthetic of style and innovation. Leeson Group offers a 10-year product warranty on this product and on all of Leeson Group's installation, an industry-leading 10-year workmanship warranty.
Then there are the Building Integrated Photovoltaic (BIPV) solar panels that can be integrated into a structure's exterior façade cladding material, therefore eliminating the need for roof-mounted systems on mid-rise and high-rise structures. Some of the advantages that BIPV have over roof-mounted solar power systems is cost savings by eliminating expensive façade material and replacing them with electricity-generating BIPV panels. Due to high-rise buildings having a small roof space, the BIPV façade can increase the solar power system size and therefore increase the sustainability of the building and lower the operating costs by reducing the electricity bill. An ever-increasing increasing benefit is the improved aesthetic of the façade, creating a new wave of architecture that many architects can include in their designs to promote sustainability.
Since BIPV is integrated into the structure's overall design, it eliminates the need to make penetrations into the roofing system for installation, thus further eliminating the possibility of a roof leak and subsequent water damage. Additionally, they don't appear as an add-on element or an afterthought to someone passing by.
With the rising popularity of roof-mounted solar panels in residential and commercial construction, builders must take the necessary precautions to ensure that they are protecting their investment and incorporating solar in their design package. Whether a builder is selling a home that already has the panels installed or a home with a "solar ready" roof, much planning must be done to avoid facing costly failures.
With so much to consider, we recommend that a builder consults with a professional Clean Energy Council accredited solar installation company to assist them in conducting a Technical Plan Review to address the systems and components used and warranty specifications for current or future installs.