Photo by Antti Veijola

Researchers in Finland have developed a flexible and recyclable organic solar panel in the form of a leaf. At the VTT Technical Research Centre of Finland pilot plant, these solar panels were printed directly onto a thin sheet of film to create a solar wallpaper that can be used to produce electricity from interior lighting or sunlight. According to the Centre, this is the first time that organic solar PV panels have been produced in shapes other than stripes using this printing method.

With the current design, the active surface of a one solar leaf is 0.0144 square meters. A set of two hundred OPV leaves can collectively make one square meter of active solar panel surface. Combined, these leaves are capable of generating 3.2 amperes of electricity (10.4 watts of power), assuming they are placed in sunny Mediterranean latitudes.

In an announcement, VTT stated that their organic solar PV panels "are manufactured with printing machines based on conventional printing methods using the roll-to-roll method, which enables the rapid mass production of the products: the printing machine can produce up to 100 meters of layered film per minute." VTT is now working to take their solar wallpaper from pilot project to full commercialization while also testing a non-organic option.

Photo by Antti Veijola

Researchers have been drawn to organic PV solar panels because, unlike rigid silicon-based solar panels, organic solar cells can be both lighter and more flexible than silicon-based PV panels. These characteristics could be advantageous when attempting to mass produce solar. However, these organic PV cells typically have lower efficiencies compared to their rigid counterparts as well as shorter life spans. According to the U.S. Department of Energy:

"Current research [on organic photovoltaics] focuses on increasing device efficiency and lifetime. Substantial efficiency gains have been achieved already by improving the absorber material, and research is being done to further optimize the absorbers and develop an organic multijunction architecture. Improved encapsulation and alternative contact materials are being investigated to reduce cell degradation and push cell lifetimes to industry-relevant values."

Photo Credit: Photos by Antti Veijola, and used with permission