With supply exceeding demand, producing the silicon panels for photovoltaic (PV) power generation has been an intensely competitive business for several years. There are however reports that a turnaround is underway. Solar industry observers like Greentech Media (GTM) state that with capacity growing only slowly, manufacturers are beginning to see signs of better margins ahead.
Quality is Key
As in other industries, one way manufacturers can differentiate their products is through superior quality. That’s one reason the National Renewable Energy Laboratory NREL is pushing for new PV quality standards. The other is that higher quality reduces waste and lowers cost.
Wet Stations for Cleaning
In solar panel production, (and in the closely related semiconductor wafer processing industry,) scrupulously high levels of cleanliness are essential to avoid defective product. One factor in this is maintaining wafer cleanliness throughout the manufacturing process, and here wet stations play an important role.
A wet station, which can be manual, fully automated, or somewhere in between, is used for cleaning wafers in de-ionized water and can form part of an RCA cleaning operation. Details vary between manufacturers, but the underlying principle is that wafers are immersed in and rinsed by clean water. Maintaining adequate water flow through the station is essential for thorough cleaning, and that's where it pays to use a quality flow monitor.
A flow monitor is a compact device that detects abnormal flow of fluid through piping. In the case of those made by ChemTec, such as the 125 Series or 125 Bypass models, a reed switch detects movement of a magnetically-suspended piston in response to changes in flow. If low or excess flow is detected the monitor sends a signal to trigger an alert or even shut down the system if necessary to prevent damage.
The 125 Series and 125 Bypass models of flow monitor were designed to help lower total cost of ownership by providing reliable, trouble-free service. Intended for lower flow applications, models are available to work with rates up to 7.9 GPH and have a broad range of adjustability. These monitors are available in 316 grade stainless, brass, and Teflon®.
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To learn more about projections for the PV industry, read this report from Greentech Media.
For information on the NREL’s efforts to implement improved quality in PV manufacturing, read their press release.
Information on the RCA cleaning process is provided in this paper prepared by the inventor, Werner Kern.