NEW TRIPOLI, USA: Solar cell manufacturers must differentiate themselves during the slowdown in the solar cell market, according to a report Opportunities in The Solar Market For Crystalline and Thin Film Solar Cells, recently published by The Information Network.
The solar cell manufacturing industry has become a “me too” business. Solar companies manufacturing polycrystalline panels buy the same polysilicon and wafers from less than a dozen material suppliers. Companies buying an amorphous silicon thin film process line from Applied Materials or Oerlikon are making the same films as other customers from these equipment vendors.
Certainly there are new avenues of manufacturing, such as CdTe from First Solar, CIGS from half a dozen manufacturers, multi-junction cells from companies such as Uni-Solar, and building integrated photovoltaics (BIPV) from an increasing number of manufacturers. These technologies differentiate these companies’ products, but the proportion of wattage manufactured, while growing, is small compared to the majority of solar panels sold using traditional methods of production, i.e., a thin film on a glass substrate.
How can the majority of solar manufacturers differentiate their products, particularly during the economic slowdown that has dropped capacity utilization to below 50 percent, and most importantly, how can they do it cheaply? Aside from the traditional lingo such as reduce costs or economies of scale, there are better ways -– increase efficiency and improve reliability.
Amorphous silicon thin film manufacturers are working on a micromorph structure in which a second layer of silicon is deposited. Applied Materials and Oerlikon are spending vast amounts of R&D to get the solar cells made on their equipment from an efficiency of less than 8 percent to above 10 percent to be competitive with CdTe and CIGS, but they are a few years away. Even so, the added cost of the vacuum equipment to deposit the additional layer can cost upwards of $50 million for a 60MW plant.
“A local company (contact me for details) has developed a coating for amorphous and polycrystalline cells that can improve efficiency between 8 and 12 percent using non-vacuum techniques so that the cost is in the cents per watt range,” noted Dr. Robert N. Castellano, President of The Information Network.
“Tunable refractive indices make these materials excellent candidates for improving both thermal conductivity and absorption bandwidths. When these unique, novel coatings are coupled with nano-enhanced polymeric coatings, significantly improved durability and extended product life can be anticipated. UV resistance, resistance to optical crazing, and the effect of adverse weather and temperature conditions is also predicted. Films can be coated on any surface,” he added.
Research was performed at an acclaimed university in Eastern PA, and the company is now looking for additional funding to optimize deposition parameters and coating properties with the intent of licensing the IP to all solar manufacturers.
Increasing the efficiency by 10 percent will increase a 50MW production line to 60MW. At a selling price of $3 per watt, that comes to added revenues of $30 million at an added cost of $1-2 per panel, that’s per panel of 100-200W, or 50,000-$100,000 per year for the 50MW facility. Imagine the possibility if this coating was put on all 7GW of power we estimate will be installed this year as indicated in a release in late November 2008.
The high costs of solar panels and their installation keep them out of the “throwaway” mentality. Long life and low cost of ownership are paramount, particularly in space applications. Manufacturing can introduce defects in solar cells that can result in low electron mobility (EM), electron traps and photo-degradation from UV light.
Part 2 of this article will discuss how these issues affect efficiency and lifetime of solar cells and the importance of measuring electron mobility at the wafer and cell stage, and how these results can increase market share for the manufacturer.