Just read this fascinating overview of the advancing solar pv collection materials coming to the forefront...it was published by the folks at Clean Edge. It will give you a really good, comprehensive...though quick...overview of the top five (5) competing technologies that are sure to give silicon based collectors a run for their money.
Amorphous Silicon is the most developed of the thin film technologies. However, it
is less energy efficient (11 percent versus around 15 to 22 percent for polysilicon), so
therefore requires more area to generate the same amount of energy. Efficiency is a
concern when space is constrained (on residential rooftops, for example). However, in a
solar farm or solar park where space is not at a premium, lower overall expense can be
CIGS (Copper indium gallium selenide) solar cells do not require silicon, but are
similarly less efficient than polysilicon. CIGS cells’ manufacturing costs promise to be
lower than PV as they can be printed directly onto glass sheets and other substrates.
Nanosolar, Miasolé, Heliovolt are among the leading CIGS companies working on
Cadmium Telluride (CdTe) cells are less expensive than silicon but not as energy
efficient. Several companies including First Solar and Q-Cells are developing the technology.
NREL currently holds the world-record conversion efficiency for CdTe of 16.5%. CdTe
and CIGS, compared to silicon, have some additional concerns in terms of the availability
and toxicity of some of these rare earth metals.
Nanotechnologies include inorganic semiconductor nanocrystals, self-assembling
nanostructures, and dye-sensitized nanometer-scale crystals. Not yet in production today,
nanotechnologies that can be printed through a roll-to-roll manufacturing processes have
the potential to substantially reduce the cost of PV.
Concentrating PV basically concentrates the light of the sun onto silicon and other cell
materials, at ratios of 2X all the way up to around 1000X. In effect, these companies can
reduce the amount of silicon or other materials required for solar power, by the amount
of concentration achieved. Companies such as SolFocus, Solaria, Soliant Energy, Energy
Innovations and others are working to bring the technology to commercialization.