US thin-film solar cells maker MiaSole announced yesterday a new world record for large area flexible photovoltaic (PV) efficiency at 17.44%. The California-based manufacturer of lightweight, flexible and shatterproof solar cells said in a statement that the Fraunhofer Institute for Solar Energy Systems (ISE) had independently confirmed a 17.44% aperture area efficiency on a commercial size flexible PV module with an aperture area of 1.08 sq m. This was recognised as a new certified record large area CIGS module in the latest Progress in Photovoltaics compendium of PV records, the announcement says.
CIGS solar cell, in full copper indium gallium selenide solar cell, a thin-film photovoltaic device that uses semiconductor layers of copper indium gallium selenide (CIGS) to absorb sunlight and convert it into electricity. Although CIGS solar cells are considered to be in the early stages of large-scale commercialization, they can be produced by using a process that has the potential to reduce the cost of producing photovoltaic devices. As the performance, uniformity, and reliability of CIGS products improve, the technology has the potential to expand its market share significantly and may eventually become a “disruptive” technology. Additionally, given the hazards of cadmium extraction and use, CIGS solar cells offer fewer health and environmental concerns than the cadmium telluride solar cells with which they compete.
A thin-film solar cell is a second-generation solar cell that is made by depositing one or more thin layers, or thin film (TF) of photovoltaic material on a substrate, such as glass, plastic or metal. Film thickness varies from a few nanometers (nm) to tens of micrometers (µm), much thinner than the conventional, first-generation crystalline silicon solar cell (c-Si). This allows thin film cells to be flexible, and lower in weight. It is used in building integrated photovoltaics and as semi-transparent photovoltaic glazing material that can be laminated onto windows.
MiaSole noted it produced the cells and record module at its facility in Santa Clara, California. The company explained that its manufacturing process deposits CIGS on a flexible substrate using high-speed physical vapor deposition (PVD).
Why this milestone record with CIGS solar cell is a big deal
Thin film solar cells have always been cheaper than traditional silicon panels but with significantly lower efficiency thereby limiting their application. With the new recorded efficiency of 17.44%, thin film solar panels using CIGS can now compete favorably with traditional silicon panels. Cadmium telluride which is the most commonly used material in thin film solar cells is also associated with pollution and raises serious concern with regard to disposal of old panels, a problem conveniently obviated with the much more environmentally friendly CIGS.
source: Solar power world