Though the Marcellus frenzy or hysteria does a good job convincing many otherwise, PA is more than gas. It is a coal, nuclear, wind, energy efficiency, biodiesel, and solar leader too.
PA today ranks 4th in solar jobs, with 4,703, according to the annual solar jobs census done by the Solar Foundation and Cornell University. See http://thesolarfoundation.org/research/national-solar-jobs-census-2011.
According to the census, Pennsylvania's solar jobs are concentrated in installation and sales with 47% and 25% respectively. About 12% of the Commonwealth's solar jobs are in manufacturing and 10% in research and development.
Pennsylvania has a prominent but shaky position in the solar boom, as California, Colorado, and Arizona are the top three competitor states and have state governments that are embracing solar, while Pennsylvania's may be losing interest. It will be interesting to see where Pennsylvania ranks next year.