Thin is in. Heliatek, a German-based solar firm, has developed ultra-lightweight solar panels that can adapt to almost any urban landscape. Eventually, this organic solar cell technology could be used to create solar-coated cars and homes. But for now, Heliatek hopes to retrofit solar panels on windows, skyscrapers, and large-area building exteriors to make cities remarkably more energy efficient.
What Are Organic Solar Cells?
All solar panels use photovoltaic (PV) cells to convert light into electricity. While inorganic silicon PV cells dominate the current market, organic PV (OPV) cells are part of an emerging technology aimed to create solar panels that are flexible, cost-effective, and potentially disposable.
OPV solar cells combine multiple layers of organic molecules to convert a wide range of light. The result: ultra-thin, lightweight layers of multicolored or transparent PV cells that absorb more sunlight than their inorganic competitors.
What Is HeliaFilm?
HeliaFilm is produced from a roll of polymer-based plastic. Layers of organic material are added to this base layer to create lightweight, flexible solar panels that can be easily manufactured and transported for use in large-scale projects.
Heliatek's organic HeliaFilm cells have four distinct advantages over competing solar panel technologies:
HeliaFilm consists of three layers of organic molecules. This "stack architecture" allows each layer to absorb and convert green, red, or near-infrared light to electricity. (Silicon-based panels only absorb visible light, not infrared light.)
HeliaFilm can convert sunlight in low light conditions and high temperatures — which makes it better suited for areas with indirect sunlight, excessive heat, or less frequent sun exposure.
HeliaFilm solar cells can connect to a wide range of building applications, from windows to concrete to buildings with irregular shapes or exteriors.
Thin-film OPV cells are less expensive to produce than silicon-based cells, which means manufacturers can produce HeliaFilm at a higher volume.
By modifying its absorber molecules and changing the thickness of its layers, manufacturers can adjust HeliaFilm's color and transparency so that it can be used on multiple building materials and colors.
Flexible, transparent, and inexpensive PV cells are crucial factors for incorporating solar technology into large-scale urban projects.
Where Has HeliaFilm Been Used?
HeliaFilm is produced by Heliatek, a joint venture by the Technical University of Dresden and the University of Ulm (both in Germany). Heliatek the first company to begin commercialization of OPV solar films for large-scale buildings.
In May 2015, the facade of RECKLI's headquarter in Herne, Germany was fitted with Heliatek's solar film. It's the first solar concrete wall in Europe, and it's expected to yield about 25% more energy than traditional silicon technology.
Image Source Image Page Source In September 2015, Phase I of Heliatek's pilot program was successfully installed in Singapore. HeliaFilm has also been used for building installations in Japan, Germany, Italy, China, and the US.
The Future Of HeliaFilm
Right now, the biggest drawbacks of OPV technology are efficiency and operational lifetime. In ideal conditions, silicon panels are 25% efficient at converting sunlight into electricity. As of February, HeliaFilm's solar conversion efficiency record is 13.2% — a long way off from the silicon PV alternative. To be commercially competitive, HeliaFilm's OPV cells have to last longer and produce more power than current rates.
Despite their inefficiencies, Heliafilm's organic cells are the future. As long as their conversion efficiency and operational lifetime continue to improve, they will be a cheaper, more adaptable technology for cities that want to reduce their energy waste.