ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades All in the name of Electrical Supply

There's a HVDC interconnector connecting Northern Ireland to Scotland. Until relatively recently, Northern Ireland's grid must have been one of the smallest non-interconnected systems in Europe as even the interconnections with the Republic of Ireland had been out of service since the mid 1970s as they'd been targeted by NI paramilitary groups during the height of the "Troubles".

Eirgrid / ESB in the Republic of Ireland are starting their HVDC "East-West interconnector" project which will connect The Republic of Ireland into the UK grid at a point in Wales.

They're putting in 2 X 500MW HVDC circuits crossing the Irish sea.

Giving access to the UK and European networks.

So, looking into our collective crystal balls, do we see any possibility of dc being feasibly used for distribution, as well as for transmission, in the future?
Alan

Trumpy- there's a 1040MW HVDC cable between N and S islands New Zealand too.
Alan

Yes Alan,
I don't think there is a South Islander that doesn't know that's here.
BTW, for those that are interested, you can download maps of our National Grid from the Transpower Page .
A rather strange fact about that HVDC link, that I never knew before is that while we can send 1040MW to the North Island as normal.
If we have a fault down here, they can only send 600MW back this way.
There's also some good pictures of the HVDC gear used at Benmore and Haywards switching yard on that site too.

[This message has been edited by Trumpy (edited 05-05-2005).]

Interesting point Trumpy about the HVDC Link. I think the "Big Islands" power deficit is due to their puny rivers and the fact that they can't play rugby.

Do I sense un soupcon de mecontente between the N & S Islands?, or is it just my imagination. Do North Islanders take the small end off the top their boiled-eggs by any chance?
(Johnathan Swift; Gulivers Travels)

Alan

Yes Alan, I suppose you could say there is a "soup-can of malcontent" between the N & S islands. More for laugh-value than any real malice though, I assure you.

Alan,
I have to agree with kiwi on this one,
there is no malice behind it.
I think what this "attitude" stems from is a statement that is used in the media here from time to time, that "if the Auckland economy ever ground to a halt, the rest of New Zealand would do the same or would suffer".
This was proved wrong when the "Blackout" occured up there, in fact things seemed to run smoother, apart from all the whinging on the evening news every night.
Naturally it was everyone elses fault that Auckland lost power and how were "we" going to fix it?.

Alan, on the use of HVDC for distribution:

HVDC is finding its way into smaller and smaller transmission lines. For example, wind power farms at sea use this technology.

Underwater power lines have to use DC for technical reasons. The longest underwater AC line is about 100 km and goes to the Isle of Man. All islands that are farther from the grid than this are connected using HVDC, if connected at all. The Swedish island of Gotland is one example. A HVDC line was built in the 50's, one of the first.

An odd example is (old) Zealand in Denmark which is connected to the rest of the country with HVDC but with AC to Sweden. Thus, the power grid in Zealand is in sync with Norway/Sweden/Finland while that in Jutland is in sync with Germany/France/etc.

quote
----------------------
HVDC is finding its way into smaller and smaller transmission lines.
----------------------

My original train of thought was, how far could dc be distributed through to local levels before conversion to ac for the consumer. Would conversion losses/capital costs of stepping down be worse than transformers, as we slowly adopt more eco friendly energy sources?

Alan