The photo on the left is of traditional solar panels consisting of polycrystaline cells, while the one on the right shows thin film technology. The most obvious difference in the two technologies is the aesthetics. Panels are typically set on stands, however, there are a few panels such as Eagle Tile’s Solar Save panel which can be incorporated into the roof itself. Thin film technology is a flexible almost fabric like substance that is being turned into shingles like Certainteed’s EnerGen shingle which is designed to work with traditional asphalt shingles or more often it is adhered to a metal roof such as the one above by Sheffield Metals.

The question is which is better?

I am no solar expert, but in doing my research and speaking with experts the answer seems to be….. “Depends on your situation” 

In the labratory the traditional panels are more efficient, but they are linked in a series and if any one cell is compromised by dirt or shading the efficiency of the entire panel or series is compromised dramatically. In contrast thin film technology is less efficient in the labratory but is much less suceptible to shading issues so it can be more efficient in a real world setting. 

According to an article I found at  Thin-film modules “can outperform monocrystalline in areas prone to hazy, overcast conditions or in industries that generate dust or high degrees of air particulates,”  The reason, he says, is the sensitivity of the thin-film cells to a broader span of the solar spectrum, including infrared and ultraviolet regions. 

Thin film technology does require more area to produce the same amount of energy as traditional panels. However since they can be incorporated into the roof design itself the visual impact should be less. Traditional panels, being mounted on racks can be turned to utilize the best angle and direction more easily than thin film, but if you are building a new building and can take these factors into consideration you can easily plan ahead to optimize your exposure, or you might get lucky and your existing building could be at just the right angle and orientation to use thin film.

As demand grows for renewable and sustainable energy resources and with the sun being an abundant source of energy, and with every building having a roof, it stands to reason that building integrated PV will be the wave of the future and it seems to me that thin film technology will be the vehicle most capable of riding that wave.

I would always recommend that if you plan on incorporating solar into your roof, you ensure that your existing roof is relatively new and in great shape. You don’t want to have to move your solar panels to reroof because you can no longer get the old t-locks that were on it.