On wto, 22 mar 2011 12:01:14 in article news:<4d888196$1@news.home.net.pl>
Piotr Gałka wrote:
> Podobno są jeszcze na świecie instalacje energetyczne 1-przewodowe w których
> przewodem powrotnym jest Ziemia.

http://en.wikipedia.org/wiki/Single_wire_earth_retur
n

More than 200,000 kilometres have now been installed in Australia and New
Zealand. It is considered safe, reliable and low cost, provided that safety
features and earthing are correctly installed. The Australian standards are
widely used and cited.