Alternative energy was a hot topic coming into 2009, but like most things this year, it has been doused with a wave of economic reality, as elusive funding and lower oil prices conspired to cool the flame. On the bright side, the temporary ebb in demand has exerted additional pressure on the photovoltaic industry to improve PV cell and module efficiencies, in order to get the cost-per-watt in line with what the consumer is willing to pay for this promising green power alternative.
The average price for a module that is capable of producing an output of 125 W or more is $4.70 per watt, according to Solarbuzz LLC, down 15 cents per watt since the beginning of 2009. There is still a long way to go. The industry needs to drive module costs down to the $1.50- to $2.00-per-watt range to be competitive against existing large grid electricity costs.
A fair number of companies in the PCB supply chain have announced solar projects over the past few years. The majority of these companies have been diversified suppliers to PCB fabricators or OEMs, not the PCB fabricators themselves. There are a few exceptions, mainly in Taiwan, where large, vertically integrated PCB fabricators have further diversified into solar cell manufacturing, but the adventurous are limited to a handful of companies that include Unitech and Unimicron (in partnership with UMC). Certainly one of the reasons for this is the capitalization costs.
Silicon PV cells account for over 90% of all cells manufactured. Investments in silicon PV cell production facilities are measured in the tens (and often hundreds) of millions of dollars. A good example would be Mitsubishi Electric’s plant expansion. Mitsubishi has been making silicon PV cells since 1998, before solar energy was on many radar screens. Late last year, the company announced it would invest some 50 billion yen and bring on another plant to quadruple its annual PV production capability by 2012, from the current 150 MW output to 600 MW. That’s about a $500 million investment for the additional 450 MW output per year, or roughly $1 million per megawatt.
What is the connection between PV cell and module production and the printed circuit industry? Suppliers to the PCB (and semiconductor) industry on the materials and equipment sides have found great synergies for their products and technical expertise. Many chemical companies, including Cookson, Dow Electronic Materials, DuPont, MacDermid and Technic, have committed resources to support advances needed in PV cell manufacturing, addressing, among other things, PV cell efficiency.
By applying well-known semiconductor and PCB processing methods, like plated metal to replace conventional PV silver paste processes, companies have demonstrated higher efficiency that translates into significant increases in energy capture. Silver and copper plating have been found to increase efficiencies by about 0.6% (the current efficiency range for silver paste is 15% to 20%), and while that sounds like a small number, it translates into a 5% increase in energy capture. Techniques that plate copper directly onto the bare silicon have been reported to increase efficiencies by 1% to 2% and come with the added benefit of a substantially lower processing cost.
You may be thinking that many of these PV cell fabrication methods sound intriguingly familiar, but the fact is that most PCB fabricators are unlikely to get into PV cell manufacturing. The cost of entry is simply too high. Frank Medina, CEO of Technica, U.S.A, a distributor to the electronics and photovoltaic/solar industries, asserts that the $80 million-plus needed to set up a PV cell manufacturing facility is out of reach for most US-based fabricators, without the support of VC or other investment vehicles. But PV module assembly capital costs are much lower, in the range of $8 million, which makes it more reasonable for larger EMS companies to seriously consider module assembly as a way to expand and diversify their products and customer base. Celestica and Jabil are doing just that, having recently entered PV module assembly and crossed over to the sunny side of the street.
To date, the solar industry has borrowed materials, equipment and processes from the electronics industry to fuel its skyrocketing growth. Grid-parity, however, will require a blending of semiconductor, PCB and nano technologies that creates a new model unique to the needs of solar manufacturing.
