Thanks Patrick Delaney who sent this link to me.  An interesting line of
solar products:
<https://www.aircraftspruce.com/catalog/elpages/aspectsolar14.php>

An interesting product line.  Especially the high end unit with the
tracking.  One big problem I see for use in a Westy for travel/camping is
that each package is self contained, has it's own battery built in.  And I
don't see any mention of using them to charge another battery.  Like
charging the aux battery onboard.  Plus, with the units set up to have the
solar panels at the battery you only have access to the battery right at
the whole unit.  That puts it outside your camper during the day.  But
looks like a good stand alone power source for small applications.