@salal

Dear what ever work is done is needs energy.
needs energy implies to theexpenditure of energy
so prototype air craft or any other scientific inventions what so ever works expend the energy.
the machine you are reffering to i charges its solar cell means it gains energy and works using and expending that energy it keeps on charging and expending energy for doing some work.

do dear it is quite imposible to work without expenditure of the energy


regards