Wafer or silicone solar cells represent the building blocks of solar panels. Traditionally, solar cell manufacturing involves a four-step process -- ingot casting, blocking, squaring, and sawing. However, these production methods waste 50 percent of the silicone material.
A few years ago, 1366 Technologies CEO Frank van Mierlo, said in an interview, “inventing disruptive manufacturing innovations is every bit as hard as inventing new materials.” According to van Mierlo, for solar power plants to reach grid-parity with coal “requires both.”
Mierlo believes his company meets the necessary requirements with its Direct Wafer manufacturing process. Direct Wafer refers to a proprietary process that produces a 156-millimeter multi-crystalline wafer from molten silicone.
What makes the technology unique?
The process creates a solar cell in a single step. Direct Wafer reduces the solar cell production costs by 80 percent. Wafers account for roughly half of the cost of solar panel manufacturing.
What formerly required up three days, 1366 Technologies performs in 25 seconds. The single-step process consumes 90 percent less energy. The managing director of venture capital for GE Energy Financial Services, Kevin Skillern said the direct wafer “can be easily fed into existing solar PV cell manufacturing lines.” GE is one of 1366 Technologies investors.
The Process
Emanuel Sach, a professor of mechanical engineering at the Massachusetts Institute of Technology (MIT), invented the direct wafer process in 2009. Sach serves as chief technological officer of 1366 Technologies. The World Economic Forum named the company one of 25 Technology Pioneer award winners. “These companies represent the latest generation of innovation and are poised to have a critical impact on how business and society work.”
With the typical silicone solar cell, electrons work their way out of the semiconductor material. These electrons generate electrical currents. The currents travel from the first layer to the top layer of the silicone. The current moves along this layer to narrow lines of silver - called fingers.
Fingers conduct electrons to busbars - the silver bands identifiable on most silicone chips. These bands cause a reduction in the quantity of sun light absorbed by the cells. 1366 Technologies has developed three proprietary processes, which solves this dilemma:
Grooved bus bars
Improve electron-conducting fingers
Decrease light reflection
The Direct Wafer fabricates the wafer directly from the molten liquid, which collects at the bottom of the furnace. A thin piece of silicone freezes in the molten liquid. It is withdrawn and trimmed to the proper dimension with a laser.
The surface of traditional wafers reflects light out of the solar module. Etching grooves in the wafer causes the reflection of the light redirected to the glass that covers the panel. The unshaded portions of the solar cell absorb the redirected light.
Numerous silver lines on the silicone shade a large area on the wafer. The 1366 manufacturing process makes the line much narrower without reducing the silicone's conductivity. It etches troughs into the wafer's surface and injects silver particles into the openings.
The next step adds metal to the particles by an electroplating that construct the fingers. According to 1366 Technologies, the process reduces the area shaded from nine percent to two percent. The cost of this approach significantly undercuts other technology on the market.
The third innovate process texture the silicone surface. This step reduces the amount of light reflected off the conventional sell surface. Other companies generally employ this method. However, the drawback has been the remaining surface area, which traps electrons. The firm's method produces a smaller service area than the other methods. The company claims this result in a one percent efficiency gain
The company claims the process easily assimilates into current manufacturing processes -“quickly and inexpensively,” according to Sach. The company continues to make inroads into reducing the width of silver fingers and fine-tuning the texturing process to increase efficiency.
DOE Loan Guarantee
The company received initial funding -- $4 million, from the Advanced Research Project Agency - Energy (ARPA-E). As a division of the DOE, ARPA-E consists of a high-risk energy technology fund that brings scientific breakthroughs and state-of-the-art invention into leading innovation. The idea is to foster the development of technologies deemed too risky for most firms to independently.
Earlier this year, the firm closed on $26.4 million in Series B funding, which is the second round of financing. The company has secured a total of $46 million from private investors. The Department of Energy recently awarded 1366 Technologies a $150 million loan guarantee just ahead of the cutoff. The program, which also approved the more than $500 million loan guarantee to the bankruptcy Solyndra expired on September 30, 2011.
Jonathan Silver describes the direct wafer technology process as “a process innovation, not a product innovation. They can produce silicon wafers with much less material and many fewer steps.” Silver serves as director of the Department of Energy's Loan Programs Office.
The company plans to use the funding to complete its first manufacturing plant (20MW) by 2013. The Lexington-Massachusetts based company plans to break ground on a one-gigawatt manufacturing facility.
Conclusion
This company has bucked the trend by focusing on developing an industry standard manufacturing process. The proprietary processes easily assimilate into existing solar panel manufacturing infrastructures. Unlike the bankrupt companies of SpectraWatt, Evergreen Solar or Solyndra, 1399 Technologies base its business model, and hence its competitive advantage, on intellectual property. The nature of the advantage makes it difficult for rivals to copy the technology.
Secretary Chu, of the U.S. Department of Energy, views 1366 Technologies Direct Wafer manufacturing process as a game-changing advance. Chu said, “As global demand for solar cells increases, this kind of technology will help the U.S. increase its market share and be more competitive with other countries such as China, which currently accounts for 60 percent of the world supply of multi-crystalline wafers.”