The efficiency of a solar panel is a measure of the amount of incident sunlight that is converted into electricity. A solar panel module rated 22% will only convert 22% of the total sunlight that falls on its surface into usable electricity. Since solar panels are made primarily for the generation of electricity, their efficiencies, that is, how well they generate electricity, are the most significant thing about them. Yet, efficiency is not the only significant thing about solar panels. Though not more significant than efficiency, the appearance of solar panels is a very important secondary consideration. Solar panels are made to look attractive. The best manufacturers are those that offer the highest efficiencies with the best looks.
With the increasing growth of thin-film solar cell technology, flexibility has become a significant design consideration. Flexibility means that solar panels can be easily integrated into spaces that are inaccessible to rigid solar panels. The solar industry trend is towards thin-film and flexible solar panels.
How Flexible Solar Panels Differ From the Norm
After manufacture, solar cells are placed inside a polymer encapsulant and sealed. Afterwards, another layer of glass is added on the front side of the panel that faces the sun. A flexible solar panel dispenses the extra glass layer and replaces it with a more flexible material that serves the same purpose. This gives them a flexibility that makes the 'bendable' or 'foldable' and able to be installed on surfaces not accessible to rigid a solar panel, like curved surfaces.
Conventional solar cells are roughly the size of a human hair in thickness. Flexible solar cells are even made less thinner.
They weigh less, sometimes up to 80% less than a rigid glass panels. This quality makes them very easy to handle, lightweight and portable.
Their flexibility means they can be installed in locations unavailable to rigid solar, for instance on curved areas. This also makes them able to fit better to surfaces than rigid glass panels.
Conventional solar panel modules require a special way of attaching them to surfaces and holding them in place. They are not weldered, soldered or hammered as they contain delicate parts that would be destroyed in the process. Contrariwise, flexible solar panels are usually mounted with an adhesive instead of mounting systems. Some even come with an adhesive backing that hold them against surfaces like a big sticker. Also, many flexible panels have grommets and can be mounted with rope temporarily. This makes them an attractive option for canopies and tents.
They can also be removed easily, transported and mounted to another location without the hassles that accompany the relocation of rigid glass solar panels.
They cost almost as twice as traditional rigid glass solar panels. The optimization for flexibility in their design adds to manufacturing costs.
They are not easily mounted in a suspended fashion and require a solid surface. This makes them susceptible to heat. Typically, beyond a certain temperature, the productivity of solar cells reduces drastically. Rigid solar panels are built to allow for the circulation of air around the cells. This makes them rather unsuitable for rooftop mounts because there they can get higher amount of heat.
In comparison to conventional solar panels, flexible panels have lower efficiency rates than standard solar panels. Though high-end brands offer flexible panels that can be just as efficient.
Generally, flexible panels have shorter life expectancies than rigid glass panels. Their polymer surface makes them susceptible to degradation by atmospheric elements and conditions. In comparison to the 25-30 years life expectancy for rigid glass panels, flexible panels are built to last for just 5 years. Sunpower offers its flexible solar panels with a 5 year warranty.
More recently, however, advanced technologies have allowed brands offering flexible solar panels to improve on their product warranties and, in some cases, even beat the warranties of rigid glass solar panels. By adding a fine wire mesh over the cells, or integrating glass fibres into the solar panel polymers or sealing the edges of the panels--manufacturers are able to offer longer warranties.
The solar industry is moving towards thin-film solar technology. All new applications of solar technology, depend almost entirely on the optimization of thin-film solar technology. Though they have a niche to themselves in the solar market and are viable alternatives to rigid glass solar panels, it is expected that flexible solar panels will grow with the industry. In the mean time, the biggest name in solar panel, Sunpower offers flexible solar panels as does many other brands. But Solarkobo does not recommend it to its clients at this time.