Updated: Mar 24, 2020
The use of solar energy can be traced all the way back to the 7th Century B.C. However, it wasn’t until early in the 21st century that roof mounted solar panels became more common in residential and commercial construction. Today, many state governments are moving towards green energy and are requiring that solar power systems be integrated into new master plans.
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 the cost of installation has substantially decreased, helped by the government incentives and rebates. By many accounts, this could be the year home builders start paying attention.
Even in regions where solar is not a requirement, more and more builders are beginning to offer solar panels or are building “solar ready” roofs that are prepared for aftermarket installation. The reason? Solar energy is not only efficient and better for the environment, but in recent studies, builders have found that having solar panels on their homes have allowed them to sell homes faster and even for a higher premium than houses without panels.
Although there are many benefits involved in including solar panels on new homes, builders must be aware of the consequences of installing the panels if not addressed correctly. There are a number of factors to consider when making the decision to install roof mounted solar panels.
Is the roofing system compatible?
Which mounting system are you using?
How will the solar power installation effect the build process?
Will the warranty of the solar power system effect the builders warranty?
Who is installing the solar panels?
So, if you have made the decision to provide solar ready roofing systems –there are many precautions you must take in your design package.
Consider safety issues associated with solar installations:
If these questions are not addressed prior to 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 you with the information you need to address the factors involved in installing roof mounted solar panels.
CHECK THE COMPATIBILITY OF 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 install, 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 on 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 are required for its install. However, one of the draw backs of a ballast system is the roof ballasts are large and in areas subject to heavy rain or snow events, the storm water 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 a tin feet to hold the rail, therefore no new holes are required. On tile roofs the a 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 DC cables on the roof are still energised. This can create an electric shock hazard for installers, people maintain the system or in the event of a fire first responders. It is important to only use qualified persons when installing, altering or maintaining a solar power system.
It is very important the system is installed using high quality materials (i.e. DC Isolators, conduits, glands etc.) to prevent water ingress and potential fires.
The Future of Solar Panels
In terms of the next generation of solar panel systems, Leeson Group is the largest installer nationally of BIPV and also has a new solar tile in final stages of development that will be released in late 2020. These solar tiles sit like a roof tile alongside normal 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’s the Building Integrated Photovoltaic (BIPV) solar panels that can be integrated into a structures 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 the roof mounted solar power systems is cost savings by eliminating expensive façade material and replacing with then 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 increasing the sustainability of the building and lowering the operating costs by reducing the electricity bill; and an ever increasing benefit is improved aesthetic of the façade creating a new wave of architecture that many architects are including in their designs to promote sustainability and increase the the overall appearance of the structure.
Since BIPV is integrated into the structure’s overall design this eliminates the need to make penetrations into the roofing system for their install, 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, it is important that builders 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 that has a “solar ready” roof, there is a lot of planning that 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.