Develop a new-generation large-capacity crystallization furnace for silicon used in PV cells to produce larger ingots at better yields and at a competitive cost.
The furnaces used to crystallize silicon for PV cells constitute a crucial link in the PV cell manufacturing chain. And the electronic and mechanical properties of silicon ingots produced play a particularly important role in both PV and material yields. The Silvie 2.0 project brought together partners with complementary know-how to take a unique, integrated approach encompassing the furnace, crucible, and carbon graphite insulator.
- ECM Technologies, the project lead, manufactures
crystallization furnaces for PV silicon
- Vesuvius brings expertise in the single-use mold, or
crucible, used to melt chunks of silicon into ingots;
the crucible is crucial to ensuring that the ingots are
- Mersen produces the graphite heating elements
used in the ECM Technologies furnaces
- The partners used CEA-INES testing labs to improve
the silicon ingot crystallization recipes and gain
a substantial technological advance on a fiercely
This new, high-capacity furnace will make producing high-quality silicon at higher production yields a reality. The extremely competitive furnaces developed during the project positioned the project partners to address international markets.
This innovative project had to overcome several technological hurdles. First, making larger silicon ingots requires excellent control of the temperature gradients via the integration of new heating elements. Furthermore, increasing the crucible diameter raises the need to rethink the traditional furnace configuration to ensure proper crystal growth. Finally, adjustments must be made to accommodate the ingot-cooling phase, which is also affected by the larger-volume production. Early in the project, the partners obtained very encouraging results on 650-kg ingots (traditional furnaces produce 450-kg ingots). Since then they have developed an even more competitive process capable of producing 800-kg ingots. This breakthrough technological advance is currently translating into commercial success for all of the project partners. The project gave them a unique opportunity to showcase their know-how while raising France’s profile as a center for silicon-ingot production technology.
From the start of the project, ECM Technologies invested in R&D and implemented a strategy to diversify its business. These efforts paid off, bringing ECM Technologies its first order for five furnaces to be delivered to China in 2010. Next came an order from Kazakhstan, where the company is addressing the turnkeyplant market, for ten additional furnaces. These major wins doubled the company’s revenue and spurred the expansion of its Grenoble manufacturing plant, where a 2,000 sq. m furnace-production facility was built for an additional capacity of 200 furnaces per year.
ECM Technologies has included high-volume sales of turnkey production lines into its sales forecasts based on projects at various stages of advancement in Brazil, Algeria, and Saudi Arabia—to name but three. In 2013 the company founded a France-based subsidiary, ECM Greentech, entirely dedicated to this business line. The company is also a member of the PV800 Export consortium funded by the French National Energy Agency (ADEME). The consortium aims to develop an ecosystem in France to produce quasi-monocrystalline (solargrade) silicon by purifying metallurgical silicon.