Solar Tracker Problem

Well i did a bit of research and found this Arduino Solar Tracker - YouTube
I am now wondering how strong are small stepper motors like this?

http://www.ebay.com.au/itm/Gear-Stepper-Motor-DC-5V-4-Phase-Step-Motor-Reduction-Step-Motor-for-Arduino-TR-/400546090138?pt=AU_B_I_Electrical_Test_Equipment&hash=item5d42684c9a&_uhb=1

The solar panel i am using is about the size of the one in the video and i can probably make my own base

is there any chance i could turn the solar panel with those motors?
thanks