Finally, I apologise for my English. It is not my mother
languish.

No need to apologize. Your English is better than some around here
that have spoken it all their lives as their mother language - and some
of them can't read/write it at all. Most of us in the US don't have a
second language so your already one up on us.

But back to the intent of the post.

I think the idea is a good one. Unfortunatly I just don't see it
happening until the technology needed is reduced in price considerably.
The model builders have some pretty efficent and probably powerfull
enough motors to be practical but I just haven't seen anything in the
way of solar panels that have the combination of output/weight/cost to
use in such a sailplane. If they exist I'd sure like to know about
them. A practical solar/electric sustainer motor might go a long way
to making soaring, in general, more popular.

Till then small turbines running on BioDiesel may be the best way in
the near future to make enviromentally friendly motorgliders.
==============
Leon McAtee
Bablefish.com .. second language for the ignorant