Integrated Solar Roofing: Why Isn’t it in the Spotlight Yet?
Being part of the design team for a new integrated solar roofing product puts us in a unique position to discuss the ins-and-outs of building-integrated photovoltaic (BIPV) technology for facades and roofing applications.
Because there is great interest from home and business owners regarding these unique and intuitively valuable products, many people continue to be surprised that the challenge of integrating solar into rooftops has yet to be solved with a mainstream product.
When I saw a(nother) question related to this topic through social media, and as 3 IN 1 ROOF nears completion of its first installations, I thought this would be a great opportunity to share my views on the subject and give both that individual asker as well as the rest of our subscribers an idea of what it really takes to design, manufacture & distribute a successful BIPV solution.
The question received was along the lines of:
“I find the idea of the BIPV modules in facades and roofs interesting. But why isn’t it implemented more? Is their efficiency really that bad at the moment? What developments still need to be made with it?”
The truth is that the energy efficiency of the product really only scratches the surface of what separates an effective and worthwhile solar-integrated roofing system from the graveyard of gimmicks and failures.
A good solar-integrated roof must actually be of a higher quality and offer improved performance over any traditional roofing or solar systems individually. This has been a tough challenge to solve until recent years, and you should continue reading to get more insights into our preferred solution and learn exactly what to look for when evaluating your next solar + roofing system.
Let’s start with the fundamentals.
To put things in perspective, the exterior of a building (especially the roof) is one of the harshest environments to design for. This is why roofs, walls, and even windows are more accurately described as “systems” - multiple products designed and installed in such a way that their combination of properties yields the desired end results.
Similar to a car, aircraft, or battery pack, products and systems made for the exterior of a building need to perform several functions across many different environmental conditions as they are distributed and used across the country, or even around the world.
The function of a roofing system, with or without solar, first and foremost is to act as a barrier against air, water, vapor, and heat as each of these elements are constantly trying to move between the outside and inside of the building.
- Must not accumulate nasty and dangerous mold,
- It can’t cause leaks when impacted by hail or confronted by extreme winds,
- It must meet some very challenging fire resistance requirements, and
- It must enhance (or at least not diminish) the way your home looks from the curbside.
In other words, a roofing system must be both exceptionally functional and fashionable - it must withstand extreme weather, temperature swings, and disaster events while at the same time providing what real estate agents refer to as “curb appeal” so that homeowners and homebuyers can maintain a sense of pride in their updated homestead.
Now before we go further, the fire resistance requirement should get some special attention here because it is an especially important and challenging aspect of BIPV design.
You see, unlike an integrated solar roofing product, PV modules using traditional rack-mounted installation methods are given special fire resistance requirements - they would never pass the same requirements as a roofing system without modification or integration with novel materials, which would increase their cost and weight.
This is not to say traditional solar systems aren’t safe when installed that way, on a rack, but having the highly fire-resistant roof underneath them alleviates a lot of the fire-protection responsibility from the solar modules themselves.
The difference is that a solar-integrated roof is not given the same reduced requirements - a BIPV roof must meet or exceed the same requirements as a traditional roofing system - same testing standards, same performance requirements and same classifications, and I’m sure the other applications like windows or walls will be evaluated similarly.
For reference, 3 IN 1 ROOF's fire test results can be found on their technical site www.high-performance-roof.com where you can see they achieved a best-in-the-business Class-A fire rating with ease.
Do BIPV / Solar Roofs last longer than traditional roofing?
So once a new roofing or integrated solar roofing product is shown that it can protect a home while it is new, the next challenge is that it must also be able to offer this protection for an acceptable period of time for a given cost.
For example, less resilient roofing systems such as, let’s say, thin shingles over tar paper and plywood, can be replaced more often because they are cheap - typically 15 years is a well-accepted milestone for a shingle roofing system, which is the most common roofing used today.
Integrating PV solar into the roofing system creates an unspoken requirement that the system survives 25 years or more, as that is the typical warranty on the power production of marketable PV modules. Your return on investment (ROI) is significantly diminished, if not totally knee-capped if your solar roof needs more than routine maintenance before this 25-year milestone is reached. Even worse would be if anything inside the home is damaged at any time due to a failure on that same roof’s part.
Therefore, it is a nearly inescapable design feature that a solar-integrated roof once installed must not be as resilient, but actually must be more resilient and have enhanced performance compared to the most affordable and most common roof-plus-solar systems (plywood + tar paper + asphalt shingle + rack-mounted PV solar) right now being installed every day.
That means no air, water or vapor leaks caused by high winds, mold, dry rot or thermal expansion, and no missing tiles for at least 25 years, not 15 years, representing a minimum 67% improvement in the roofing system's expected lifetime.
You would be greatly surprised (and disappointed) to learn how many solar roofing products will fail in one or more of these areas before reaching that 25 year milestone.
Considering only the topics of fire resistance and longevity performance so far, it should be no wonder why the leading solar-integrated roofing solutions available cost more to manufacture & install than their rack-mounted predecessors right now, and why the less costly ones have failed - they are required to be of higher quality.
Wait, we haven’t talked about energy yet… isn’t a solar roof supposed to provide us with sustainable energy too?
That’s right, everything I’ve mentioned so far only describes the solar roof’s performance as an acceptable and safe building product - these are the bare minimum just to get into manufacturing, let alone past first-inspection or to actually earn industry respect. The other aspect to consider is the product or system’s ability to be installed and actually provide that ROI mentioned before.
Of course, an integrated solar roofing product should produce as much electricity as possible and be a profitable investment.
Realistically though, the design elements which greatly influence both final cost and the amount of clean, affordable energy and cost-savings provided, are basically the LAST things to be considered by a design team (once again, because performance as a long-lasting roof is so complex and important).
The design elements and features which impact solar energy production and ROI, besides basic roof performance, include:
- Heat shedding - the less heat build up the better,
- Solar cell efficiency - power output per square-foot is very important,
- Manufacturability - the solar industry is largely automated to achieve low cost-per-watt, and
- Installation process - don't forget about labor costs!
We've found that simpler is usually better - less costs, better adaptability, and less risks of mistakes.
The Bottom Line
The paradox here is that cost & energy production tend to be the most important features as considered by you, the consumer, and where the conversation is centered because everything else I mentioned above related to environmental and disaster protection is simply just “expected.”
It is a mistake to compare a BIPV Solar-Integrated Roof with a traditional roof + traditional solar installation apples-to-apples -
A High Performance Solar Roof must perform the functions of both, except better.
The bottom line is that a solar-integrated roofing product must actually be more resilient than a traditional solar system and offer better protection than a traditional roof. Then and only then can it provide a truly worthwhile "bang for your buck".
And who benefits the most from these high performance standards for solar-integrated roofing? Well, you the homeowner of course! You can be sure that the right High Performance Solar Roof is one of the most worthwhile investments you can make, and you'll enjoy a safer, more comfortable, efficient and attractive home for many years to come. It may even be the last roof you'll ever need!
A challenging feat indeed, but not impossible.
Learn more about our preferred solution & tell us your thoughts.
Obviously we find the idea of BIPV modules in facades and roofs interesting too, so much so that we’ve invested time and energy into helping to develop one.
But take it from us, the reason it hasn’t been done on a broad scale yet is simply due to the fact that it is a more difficult challenge to solve than most give it credit for - consumers and Engineers alike.
Finding the magic blend of materials, parts and design to offer not just an adequate efficiency, but superior protection, easy installation, curb appeal and affordability all at the same time has taken a long time, but we believe that now the technology for the future of roofing is finally in hand.
Let me know your views on BIPV and integrated solar roofing products. For more information, please reach out to us and check out our preferred solar roofing product, the 3 IN 1 ROOF.