There has been a lot of buzz lately about solar film, also called flexible or foldable, solar panels. This is an emerging technology and could completely revolutionize renewable energy. Thin film solar most often uses CIGS (copper indium gallium (di)selenide) technology or amorphous silicon, which are much cheaper and easier to manufacture than the standard solar crystalline panels we're used to seeing. Let's break down the different advantages and disadvantages of this new and exciting technology.
Advantages:
Cost. Flexible solar is leading the way to cheap energy from the sun. Costs for this technology are dropping quickly and with the investment in research and development, these costs will continue to fall.
Application. The biggest advantages currently with thin film solar is its numerous application options. Unlike traditional panels, flexible panels can be applied to a wide variety of surfaces. In addition to the traditional roof mounted design, these cells are being molded to cars, backpacks, clothing, and even windows. Some companies are even integrating the cells into things like roof tiles and siding, so your house will have solar in it, not just on it.
Technology Advancements. Many large companies such as Shell, Honda, and Nanosolar are throwing all their research muscle behind thin film solar. This means that the technology will improve greatly over time, and some of the advancements are already coming to market.
Fewer Defects. Because the manufacturing process is simpler, there are often fewer defects. The highly technical method of building traditional solar panels, sometimes compared to computer chip manufacturing, involves a lot of detailed soldering. This has been historically a place where the traditional panels experienced a lot of warranty issues. Not so with solar film. The process is closer to printing and therefore is subject to fewer defect issues.
Less Voltage Drop. Electricity in most applications flows better when its cool. When thin film solar cells heat up they tend to loose less voltage than traditional panels.
Performance in Low-light. Many thin solar panels have better energy production in low-light and shading situations.
Durability. Since the technology is fairly new, there are some questions about how long these cells will last. But many early-adopters have reported their cells lasting 15 years and more. These cells do not require the glass and aluminum casings of traditional cells because the materials within them are flexible and malleable, not brittle like crystalline silicon. This means they will likely take more abuse and last longer.
Disadvantages:
Efficiency Questions. Efficiency of these cells has lagged anywhere from 50%-70% behind that of traditional crystalline cells. This is changing quickly however. In 2005, the National Renewable Energy Lab achieved a world record 19.9% efficiency for a CIGS cell. This means that 19.9% of the total energy that fell on the cell was converted to electricity. This is approaching the world record for a common solar panel of 24.7%.
Space Needed. With the efficiencies currently available, you would need approximately 50% more room with thin film solar to produce the same electricity as a traditional solar setup.
Heat Retention. Because thin film solar is usually applied directly to a surface, they can retain more hear. Traditional panels are generally installed with a standoff, meaning there is space between the panel and the supporting surface, allowing for air to cool the panels. Thin film solar may retain more heat, creating a balance act between this and its benefit of better performance at higher temperatures.