Based upon the experiences of other industries, technology developments in solar cell efficiency and increases in manufacturing economies of scale will not be enough for photovoltaics to reach grid parity goals as fast as the world desires. The solar PV industry needs to look at meaningful cost reduction through a global, robust and well-organized supply chain.
The current learning curve for the industry is not as steep as other electronic industries, especially semiconductors, which use many of the same processes, materials and suppliers as PV. A faster learning curve for the PV industry could be accomplished through better industry collaboration, including industry standards and technology roadmaps.
The progress made by semiconductors in cost reduction is one of the technological marvels of our time. Since 1975, the cost of one transistor has been reduced by a factor of ~4 million. This achievement has often been ascribed to Moore’s Law, the prediction that the number of transistors that can be placed inexpensively on an IC would double approximately every two years. Learning curve cost reductions summarized by Moore’s Law have led to the dramatic market expansion of chips into nearly every facet of modern life, and many observers see it as a useful guide to cost reduction in the PV industry.
Although thin-film and crystalline silicon (c-Si) cells do not benefit from lithography-enabled feature-size reductions that comprise many of the cost reductions in semiconductors, much of Moore’s Law is directly related to productivity, yield and other cost reductions not related to feature-size reductions. Since PV manufacturing is based on many of the same processes and materials as IC and display manufacturing, there remain important lessons from these industries that can be applied to solar cells and modules.
For more than 20 years, keeping pace with Moore’s Law was accomplished by individual companies, working independently on common technical problems. For decades, the idea that a technology roadmap for semiconductors was necessary to sustain an acceptable rate of industry progress was simply not part of anyone’s expectation. It was not until the 1980s that the first international roadmap for technology development was produced. Today, the International Technology Roadmap for Semiconductors (ITRS) is recognized as a natural and necessary compass and integral component of the IC industry.
Many see the ITRS process as an effective way to identify and target key requirements. Some also believe that the PV industry could benefit from the experience of the ITRS. There are both similarities and differences between the critical roadmap issues in chips and PV. Both involve substrates, interconnects, absorber/efficiency, metrology, packaging and test. Both have common business drivers such as cost reduction, throughput, quality and reliability, and sustainability. PV is clearly different from chips, however, and does not have the powerful organizing paradigm of the next process node that helps ground the semiconductor roadmap.
Industry standards also have a close relationship to technology roadmaps. It has been said that roadmaps without standards don’t work. Roadmaps are the group view of the technology path over time. Standards are the tools the industry uses to identify the set of specifications that define industry requirements. Several studies have identified billions of dollars in industry costs that the semiconductor industry has eliminated with standards. Are there similar costs in the PV industry that can be reduced with a smart standards effort, getting PV closer to grid parity? Many believe there are.
The PV industry is just starting to address roadmaps and standards. Several manufacturing standards have already been adopted by the industry, and there is a growing participation by key constituents in the standards development process. Active PV standards committees are in place in North America, Europe, Japan and Taiwan under the SEMI International Standards Program, the same platform and process that supports IC manufacturing standards.
One major standard specified how different machines or processes communicate together, a fundamental requirement for the modern automated factory and huge contributor to manufacturing efficiency. The standards effort in PV appears to be well on its way to contributing to a steeper learning curve.
Roadmaps are just now being considered by the industry. A recent survey of cell and module manufacturers, equipment and material suppliers, and other key players ranked lack of an industry roadmap and effective collaboration second behind government polices as a key barrier to industry growth. However, some industry participants believe it is too early for a technology roadmap and that engaging in an open, public dialog could be harmful. Collaboration opponents object that roadmaps cannot define industry growth in such a dynamic market environment.
Technology roadmaps and industry standards are complex issues for the industry to consider, involving fundamental issues of competition and cooperation. Along with the recently formed European Crystalline Cell Technology and Manufacturing Group (CTM), discussions are underway between other key stakeholders around the world trying to identify areas where cooperation makes sense. As these discussions continue, the industry has the opportunity to learn from the semiconductor industry and find its own path, to find its own Moore’s Law that drives down costs and accelerates grid parity, enabling a great solar era unsupported by government incentives.
SEMI’s PV Group has organized a PV Industry Collaboration Workshop taking place today at 2-6 p.m. at the Intercontinental Hotel, as part of Intersolar North America. The workshop features presentations from several key industry participants, break-out sessions, and conclusions and consensus on priorities moving forward.
— Bettina Weiss, Senior Director, SEMI PV Group