3 ms·
Can’t tell if trolling or not. The cables have water barriers so the conductors + insulation remain quite dry.
by gehsty 8y ago
Can’t tell if trolling or not.
The cables have water barriers so the conductors + insulation remain quite dry.
- Analemma_ 8y agoI believe the parent meant that the alternating current creates an electric field which is then absorbed by the water, leading to energy loss. This happens to some extent to all AC transmission, but I don't know enough to say if seawater+AC is a particularly bad combination. It would make sense though, because it's more conductive. EDIT: brandmeyer's comment explains it well: https://news.ycombinator.com/item?id=16903431 https://news.ycombinator.com/item?id=16903431
- TeMPOraL 8y agoYes, that's precisely the thing I was referring to. Wasn't sure about the correct terminology (not an EE) so I didn't try to make the comment sciency-souding :).
- gehsty 8y agoI work installing these cables and never heard this discussed, maybe at the voltages / transmission subsea cables work at (220kV, 1000s of amps) makes this effect negligible?
- TeMPOraL 8y agoI honestly don't know. I'm not an EE, I only reported on what I've heard reported on the topic (and that passed my "basic physics sniff test").
- rsynnott 8y agoAre they AC? My impression was that practically all vaguely modern undersea cables are high voltage DC.
- gehsty 8y agoIt depends, when talking about interconnecting cables between countries, yes the majority are DC, both to minimise transmission losses and also to tie together grids working at different frequencies.... In terms of km installed I think it will be HVAC just from the sheer number of offshore windfarms built over the last 10yrs in Europe. These things can be huge - 60km in length, 220kV ~1500A....
- cesarb 8y agoSalt water is a conductor. Two conductors separated by insulation make a capacitor. This extra capacitance makes AC less efficient.