Working with a quote from Squires e-mail to DMcD5-
You need to be able to produce at least 100 Kg per day to support a 1GW/annum production plant and you cannot accomplish this using a beaker line.
He also made a supposition that Solterra sells the solar cells at $1/watt:
Playing around w/ these numbers makes me believe that there will be tremendously more profit by investing w/ Quantum than w/ Solterra just on the solar end.