Re: Double Tracking and Underground Utilities
Author: mook
Date: 06-03-2014 - 22:38
Tesla WAS right - for his time, which was prototype "steampunk" and did not have high-power solid-state electronics available. At lower voltages, AC is still the way to go, since transformers and connections are relatively simple. They do waste power, though, and at very high voltages AC gets really squirrely. DC very possibly is the way to go for that.
At least when they were built some of those very-high-voltage lines from the Columbia River to SoCal were DC for the same reasons it's being promoted now. They had much lower loss. Of course, the converter stations were subject to severe damage from earthquakes (replacements were reengineered), as are for that matter the big substations used to terminate or otherwise connect to very high voltage AC lines. IIRC there was also a problem with high ground return currents that forced some changes in how the wiring was done. Sounds like that under-the-bay line mentioned above benefitted from that experience.
And none of this is directly relevant to what EPA is doing - attempting to reduce carbon emissions from combustion-powered electric generators. Indirectly perhaps - reduced loss would mean less power needs to be generated in the first place, meaning less fuel (of any type) burned. But if you work out the numbers, I suspect it would be a marginal benefit though it would still be useful (especially for hooking up utility-scale solar as a partial combustion alternative).