Thin film solar cells (TFSC) generate electricity from sunshine or bright indoor lighting. The first TFSCs were introduced in the 1990s to power hand held calculators. TFSCs are made by attaching extremely thin photovoltaic (PV) materials such as amorphous silicon. The thickness of the PV materials is measured in nanometer or micrometers. These materials are applied to a base such as glass, metal or plastic. Before the PV materials are attached, the base surface is treated with a layer of transparent conducting oxide.
At first glance, the thin film solar cells seem to be inferior to the traditional photovoltaic cells in use today. The TFSC generates 50 percent less electricity than conventional solar panels and costs about 10 percent more. The main appeal of these TFSCs is their light weight, smaller size and flexibility. These advantages allow homeowners to use thin film cell technology where regular PV systems are not practical.
TFSCs are growing in market share of the Los Angeles area market for several reasons. Thin film solar cells are much better able to withstand earthquakes and other natural disasters such as hurricanes and tornadoes. Their light weight and lack of bulky frames found in regular PV installations make them less detrimental to roofs. Their flexibility means they can be applied to surfaces that will not accept regular solar cells, such as curved surfaces. This helps offset the lower power output of the TFSC.
An example of TFSC can be found at Carl Harberger’s house in Los Angeles. It is a 6,000 square foot home with six refrigerators, five TVs, a pool and plenty of computer workstations. Mr. Harberger chose TFSC over solar panels because he has a sheet metal roof which would require drilling to install the brackets needed to support solar panels. He also liked TFSC for its safety in an earthquake. The TFSCs will generate 24 thousand kilowatts when the installation is completed and approved by the building inspectors. The panel builders, Uni-solar of Auburn Hills, Michigan and ADR Solar Solutions, a local PV installer, believe this to be the largest TFSC application in the USA.