At 20:24 04/08/99 -0700, Ron Fial wrote:
>efficient than AC 3-phase transmission, but the cost of the AC/DC conversion
>only makes the DC transmission have better economics if the line is over 500
>km over land, or 20-50 km under the sea, or 40 km if all wires are
>underground.   Here are some interesting facts about this stuff.   I don't
>know why it only takes 20 km underground for DC to beat out AC.  Maybe its
>only one insulated wire required, so only one narrow trench?  Any other
>guesses?

for underground and even more so for submarine cables the capacitive
transmission losses may be higher, maybe.

ge