[kzrdude]

Interesting map. Astounding number of repeaters needed on a cable (you can show this in a map layer).

They must deliver some power with the cable to handle the repeaters? I wonder how much power it requires and if it's hard to ensure it doesn't break.

[iptrans]

The cable landing stations provide DC power for the repeaters from both directions. The power requirements are substantial and use thousands of volts.

All the components of the subsea cable system are engineered with reliability in mind. None of the components are to require maintenance over the lifetime of the system. This means components are expected to operate 20 to 25 years at a minimum.

[jsjohnst]

> The power requirements are substantial and use thousands of volts.

While 100% correct statement, the wording here could potentially lead someone to make an invalid assumption.

The core reason why it’s “thousands of volts” isn’t because a lot of power is needed specifically (although that is the case), it’s because of the nature of electrical conductors. Power loss over long distances is much more heavily influenced by current (current is squared in fact in the equation) rather than voltage. To say another way, you’ll have a lot less power loss with 50k volts at 100 amps than you would with 250V at 2,000A, despite both having comparable wattage (this is in part why high voltage power lines exist on land). Another reason is that electrical conductors (especially with copper, but also with aluminum and others) are heavy and the higher the amperage, the larger the conductor needs to be and thus the more weight.