I have been doing my testing with the  harbor freight 45 watt solar panel system.  You can get the price down a bit with a coupon but even then its still   $3.25/watt.  Panels have dropped dramticly in the last couple of years.  I was able to get 2 100 watt panels for just under $1.40/watt. 2 panels ordered. With Amazon prime free shipping. Should be here in a couple of days. Now need to get a hole dug for the mounting pole. more to come.