It’s sleek, it’s sexy, it’s new; Tesla’s Elon Musk is at it again introducing a bold new technology into a booming industry. But is it really all that new? Will it really be the next best thing in solar?
No.
If you haven’t already seen it there is no doubt they will impress you. An integrated solar PV system right into your roof that is aesthetically pleasing for less than the price of a new roof, Musk says.
The thing is… Haven’t we seen a similarly integrated roof tile or shingle around town? This technology already exists with offerings from Certainteed and Dow Powerhouse. The later recently went out of business in fact.
The truth of the matter is that these companies may have paved the road but that road seemingly leads nowhere. Integrated solar roofing products were a great idea with aesthetics in mind for those customers with an optimal solar roof that happens to be on the front of their home.
Unfortunately these integrated products simply aren’t as efficient as a traditional panels that continue to advance. This isn’t the only roadblock that this technology has hit.
Wouldn’t most people revert to a fundamentalist approach that a roof is designed to wick water so why would I add an electrical element to rely on for the same function. There are reasons why traditional solar is mounted above the roof surface. For one, this leaves the roof unobstructed to perform its duty. The other is the fact that electrical wiring doesn’t work as well when in extremely hot conditions such as being on the roof. Being mounted above the roof allows air flow to reduce the production loss by heat.
Another problem with an integrated roof is the fire marshal. Or should I say the fire marshal WILL have an issue with your all solar roof. In San Diego County the fire marshal requires three foot access clearances on the sides and top of solar arrays. When you have a house fire, one of the first things a firefighter will do is pull the meter at your electrical panel. In doing so there is no electricity being fed to the house to reduce damage and spread of the fire. The second thing firefighters will do is get on the roof and hack a hole with an axe at the top ridge where the fire is located.
So now imagine an all solar roof. For safety reasons it simply won’t work. Fire codes, National Electric Codes, and California Electric Codes will still be enforced. These fire access paths will still have to be upheld and I would assume there would have to be some sort of differentiating factor between the normal tiles and solar tiles. These tiles will be run off of DC electricity so during daylight hours current will be running through these solar tiles and can not be turned off. These are unlike your home that is run on AC power. Can you imagine how unsafe it would be for a firefighter to cut into a live solar tile trying to save your home from a fire.
Code enforcement is on the rise and we hear every year that the fire marshal is trying to expand the fire access pathways to further ensure the safety of his firefighters. With a traditional solar PV system it is easy for the firefighters to distinguish the difference between solar panels and the roof surface.
The last problem I see with this 100% building-integrated PV solar roof is the way DC electricity works. With DC solar panels they have to be wired together in series as these tiles would be. Direct current (DC) is very finicky though, if one part is shaded then that string of panels or tiles will only produce to the lowest common denominator. If you were to look at your roof you would see all kinds of peaks and valley with opportunities to shade one another. On your roof you will also see plumbing, exhaust, and other vents that create minimal amounts of shade that will severely hurt the production of a roof tile system. Your house also has four sides, why would you place solar PV on a north facing roof? We don’t, it doesn’t make sense any way you look at it.
Sure it might look good but it’s already failed with companies with like products going out of business. Traditional roof mounted solar as you see on your neighbors house works. Solar panel technology is getting better every year with the ability to produce more power per square foot allowing solar contractors to use less and less of your roof.
Get the most out of what you are paying for by choosing the technology that works and keeps on working. Efficiency is the highest its ever been, financial incentives are still available, and the return on your investment to become energy independent makes the decision to go solar a no-brainer.
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