Hello Mr. Pascali,

Congrats on your progress to date on all fronts.  I have a question regarding the Gen1 Purevap report, and I've decided to post it here for some scientific clarification.

First, a couple of quotes from the Gen1 Report Summary, found here (http://www.hpqsilicon.com/wp-content/uploads/2017/11/HPQ-GEN-1-FINAL-REPORT-SALIENT-POINTS.pdf) :

"Theoretical calculations, assuming a 100% production yield, estimating the ultimate purity for a series of key tests were calculated based on actual impurity removal efficiency for each test. Overall the result shows that purity of the Si produced under various conditions could range from 3N (99.984 % Si) to 4N (99.996 % Si) for low purity feedstock, to purity close to 5N (99.998 % Si) when using high purity feedstock."

"The ability to operate semi-continuously may achieve a maximum production yield of 90%, as typically obtained in industrial scale reactors."

Am I reading this correctly - that in theory, with 100% yield, based on actual impurity removals, we could range from 99.984% to 99.998% Si?  In other words, even in theory with 100% yield 5N wouldnt be achievable?  And Gen2, which will hopefully operate somewhere close to 90% yield, may naturally fall short of these theoretical numbers because of the lesser yield?  Can you please clarify.

Also, is there anything to report in terms of Boron and Phosphorous removal in the final tests of Gen1?  There were less details in terms of the impurity removal breakdown, and I recall these are important elements.

In short, I would really appreciate some clarification on what you think is possible with the Gen2 mini plant and ultimately the Gen3 pilot plant, and how solar silicon will arrive.

Thanks in advance for any information you can share.

Duff