On Sun, 27 Jul 2014 22:33:37 +0100, "Nightjar \"cpb\"@" "insert my surname
here wrote:


Like the man says, although the problem is significantly greater under
water. 30km is about the limit for AC transmission under water, which is
why our links to the continent are HVDC. Even then, the cables are very
specialised and there are IIRC only three manufacturers of HVDC
underwater cables in the world. That is a limiting factor on how many
offshore wind farms can be built, as they need HVDC underwater cable,
the manufacturers have a limited capacity and well filled order books,
while increasing capacity is not something that can be done overnight.

Some, but I'm not sure exactly what proportion of UK offshore wind farms have AC
substations located offshore and an AC connection to the existing grid /
distribution network. I can see DC being of use in the truly offshore arrays
that Germany operates that are out of sight and over the horizon but for the UK
wind farms that are located much closer to shore there seems little or no point
in converting to DC.

There is mention in this article clearly implying an AC connection and
interconnection regime for the London Array the biggest of the white elephant
monstrosities to pollute our country.

http://www.theengineer.co.uk/sectors...012971.article

There is a 600kV 2.2GW mainly underwater DC connection currently under
construction between Scotland and the Wirral to carry the output from wind
generation but this is a point to point grid connection with no directly
connected generation.




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