manual_tranny OP t1_ixcww54 wrote
Vibrant Clean Energy (VCE) has proposed a ~210 line underground high-voltage DC transmission line network, with underwater lines along coastlines, which would improve the efficiency of electricity distribution across the US.
In the lowest cost scenario, solar capacity is expected to exceed 830 GW and wind capacity is expected to exceed 1130 GW, by 2050.
The colossal transmission system would cost only $400B if financed over 30 years at 3%, which would result in a cost of $7.5 per MWh, enabling extremely low electricity costs of $25/MWh. (That's $0.025/KWh)
gerkletoss t1_ixd2pph wrote
Why underwater along coastlines though? Isn't that just harder to service?
EDIT: Perhaps my favorite thing about the r/futurology mods is the opaque childish behavior.
AcaiPalm t1_ixd5fg1 wrote
Cheaper to bury the cables to safe depth at sea compared to routing through overcrowded coastal area. Think of crossing roads, railways and rivers and dealing with topography and the cost of purchasing land for the cables. You can repair cables offshore but it is expensive and a bit risky as repair joints in marine cables are more likely to fail.
gerkletoss t1_ixd6jet wrote
But then why not just put it further inland and run branch lines off to the few places where this connects to local grids?
AcaiPalm t1_ixdee9d wrote
This game isn’t to improve grid connectivity at that resolution, you would need to convert the DC to AC in order to feed it into the main distribution (overhead lines etc). This would be costly and require more substations and infrastructure to meet a relatively small demand. It’s more a method of transmitting large amounts of electricity to the primary electrical hubs, usually locations where it is generated or consumed in large quantities (Power stations, industrial areas).
As you move into a more diversified energy mix which contains renewable sources you need to be able to rapidly and efficiently move the energy away from where it’s produced to where it’s not. This allows you to deal with the impact of varied meteorological controls on energy production, i.e. it only being windy or sunny in one state.
gerkletoss t1_ixdguka wrote
Yes. Those hubs are the few places it connects to local grids that I mentioned.
grinningbearit t1_ixd3pdu wrote
Just a shot in the dark, but maybe less maintenance and interruptions to service?
But I agree, I'm curious about the feasibility of that.
I'm also curious how shifting coastlines could potentially impact it.
gerkletoss t1_ixd5wvd wrote
It's certainly a thing that can be done. I just don't see the reason for it.
grinningbearit t1_ixd774g wrote
I agree. By feasibility, I more meant is it worth compared to the alternatives rather than is it possible. It might not have been the best word choice
chickenderp t1_ixd4lcj wrote
I'd be more worried about leaking insulating oil into the ocean, to be honest.
danielv123 t1_ixdx3z2 wrote
Long undersea cables isn't a new thing. New windmills are built at sea every day. There are a dozen undersea high power cables in northern Europe. There is a planned cable from Egypt to Greece and one from Algerie to the UK.
chickenderp t1_ixfwbmq wrote
don't get me wrong I'm not poo-pooing HVDC transmission, I just personally think I'd rather have it on top of transmission towers than underwater.
mweint18 t1_ixdx44c wrote
Modern Subsea DC cables are not insulated with oil anymore.
chickenderp t1_ixfw2x3 wrote
Someone needs to tell the utility I work for to get with the times then :p
Splenda t1_ixe9t46 wrote
Subsea lines avoid the politics of overland routing. When you're running a line 2,000 km on land, every local government enroute wants a piece of the revenue.
Hence, the 3,800 km Xlinks line that will soon power much of the UK from Morocco skirts the coasts of Portugal, Spain and France.
gerkletoss t1_ixea5iz wrote
That one has to go along the seabed though, and involving mote countries is a whole extra level of headache compared to this proposal if the coastal lines were moved inland.
I'm not saying it's wrong, but I'd really like to see the trade study.
planko13 t1_ixdcm23 wrote
No NIMBYs to whine about it
BoomZhakaLaka t1_ixex70k wrote
This is an inverter manufacturer's wet dream. Someone benefits tremendously by building a new bulk interconnected DC system. As someone in operations & planning with an understanding of the underlying technology (DC/DC converters) I understand the benefits but I'm still skeptical.
Even at 1000kvdc the losses for transmitting power from Nevada to new York would be pretty substantial, and I have doubts that the benefits outweigh the cost. Though I do understand the energy potential in the southwest, this must be weighed against the trade-off of keeping generation regional.
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