Bob, I picked one up several years ago virtually identical to yours...it is pretty neat to "fire it up" with nothing but sun light.
These PM products originated in the Phoenix, Arizona area...I was there a week ago and I swear a sun driven engine would run from early morn til late in the evening...very intense sun and it isn't even summer yet. My son lives there and I was visiting...he had just gotten solar panels installed on his roof...just awaiting inspection by local power company before hopefully cutting his electric bill in half. If solar electric generation can work anywhere in the world...Arizona should be ground zero!!!
Rog