In 1916, the Polish chemist Jan Czochralski (cho-krahl-ski) was writing notes in his laboratory. Modern legend has it that while lost in thought, he mistook a vessel of molten tin for his inkwell. After absentmindedly dipping the point of his pen into the molten metal, he removed it and found strings of crystals forming one after the other. This eureka moment was documented and published in 1918 in a German journal of Physical Chemistry, under the title “Ein neues Verfahren zur Messung der Kristallisationsgeschwindigkeit der Metalle” [A new method for the measurement of the crystallization rate of metals], Zeitschrift für Physikalische Chemie [Journal for Physical Chemistry.]
The Czochralski (CZ) method of crystal seeding and growth has been adpoted by the solar industry and stood the test of time. It is a reliable and efficient way to produce high-quality silicon stock for solar photovoltaic cells. Many of the global leaders in the solar PV industry, including Q-cells, Suniva, Sunpower, REC Solar, and Canadian Solar Inc. still employ this process in their manufacturing plants. Today, roughly 1/3 of the solar capacity worldwide is produced using the Czochralski process.
Crystalline solar cells were developed in the U.S. in the 1950s, and were soon providing power to NASA satellites. In 1970’s, the OPEC oil embargo added an impetus for cheaper, local, and sustainable energy sources. Most of the major fossil- fuel companies, including Exxon, Arco, Mobil, BP, and Shell had solar divisions, which conducted research, development and manufacturing of this exciting alternative technology. Oddly, this is no longer the case.
Fast forward to 2016. The solar PV market has evolved through four decades. Advancing technology, improving efficiency, declining prices, and global supply chains have brought PV prices down from $100 / watt in 1971 to less than $1 today. Humans are making solar cells that are more efficient than plants’ photosynthetic pathways. What was once a fringe market, is now a lucrative alternative to paying the grid for fossil-based electricity. Today in the northeastern U.S., in non-subsidized terms, every 1,000 kilowatts of solar electricity installed will save about $5 million dollars, and avoid about 2,300 tons of heat-trapping CO2 emissions over the lifetime of the solar panel. Where have we to go, but up?