Bramford to Twinstead 400kV line

My Input To Grid Capacity Consultation

I understand that the grid connects generators in what were coal producing areas of the Midlands, coastal nuclear stations and gas fired generators to the major cities and industrial areas.  As we move toward greater use of renewable energy the grid must be enhanced to cope with energy sources that fluctuate wildly.  There are considerable difficulties but I believe we must connect these assets and learn to tolerate their characteristics. 

I appreciate that National Grid is responding to requests to connect new generating capacity in Suffolk by proposing that it increases the capacity of the 400kV grid connection between Bramford and Twinstead Tee in Essex.  They propose that this should take the form of an additional 400kV twin circuit line to supplement the existing line taking one of four corridors between the end points.  In addition a number of existing connections will be up-rated by replacing conductors, particularly that to Norwich, beside the A140.  The sub-station at Bramford will be upgraded.


My view is that the proposed lines will be unacceptably obtrusive in any of the corridors, with those where the line crosses high open country worse than areas where land form and vegetation form a partial screen.  However, I do not see any clear choice between routes on this basis.  All have sections that offer screening and sections that do not.  Twin pylon lines like that from Bramford to Sizewell are much more obtrusive than a single line but I do not believe that this is sufficient to warrant intrusion on an entirely new group of people, a new area of countryside and the consequent damage to our tourist industry.


Underground lines would be unobtrusive in operation but very disruptive during installation and at a cost.  Estimates of that cost vary widely from a European estimate of 7 times the cost of overhead to 17 to 25 times in estimates from the National Grid.  I believe that underground options should be explored in some detail and take into account improving technology and the cost reductions which are occurring as under-grounding for 400kV connections is forced by activist pressures.  The National Grid “Optioneering Report” points to recent technology change as a driver for significant cost reduction in the cost of Bramford substation upgrade.  Such reductions undoubtedly apply elsewhere.  Options such as in-tunnel installation of gas insulated or polyethylene (XPLE) insulated cables should be considered with realistic cost estimates taking account of the lifetime reduction in circuit loss.  Installation costs should be balanced against the full costs of long term damage to human habitat.


We should remember that although increased capacity is necessary to allow us to exploit an increase in nuclear and offshore wind generation that capacity is not required for some years.  I do not find the present proposal acceptable and do not believe that the population in the area affected believe it to consider parameters other than cost and simplicity.  I would urge National Grid to evaluate alternative technologies, particularly underground lines and gain the advantages of lower fault incidence, reduced loss, fewer planning issues and less damage to our quality of life.

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