National Grid launched a public consultation in October 2009 on four possible route corridors for a new overhead power line, between Bramford substation in Suffolk and Twinstead Tee in Essex, to connect a number of new power generation sites to the national electricity transmission system.
For more detailed information please see the various documents available here and to submit your views please visit our Bramford to Twinstead 400kV overhead line project web site.
Route corridor options
Following initial environmental and technical studies, we identified four broad route corridors within which an overhead line could be located.
Corridor 1
Option 1 is to build a new overhead line running south-west from Bramford, largely in parallel to the existing 400,000 volt National Grid electricity transmission line and the 132,000 volt electricity distribution line owned by the distribution network operator EDF Energy Networks. This would result in three lines following roughly the same route: the existing 400,000 volt line, the new 400,000 volt line and the existing 132,000 volt line owned by EDF.
Corridor 2
Option 2 is to take down the existing 132,000 volt distribution line, currently owned by EDF Energy Networks, and build the new 400,000 volt National Grid transmission line in its place. This would run largely in line with National Grid's existing 400,000 volt overhead line to Twinstead. This would mean that there would still be two lines running along roughly the same route, but both would be the larger size of pylons.
Under option 2, to secure supplies for local electricity customers, replacement infrastructure will be required. National Grid has been working with EDF Energy Networks to develop a solution.
Work to date has indicated that for option two, a new electricity substation would be needed in the vicinity of the overhead line, between a point west of the power junction at Twinstead Tee and a point east of Castle Hedingham. Our substation siting studies have identified three areas where it may be possible to site a substation.
Corridor 3
Option 3 is to route the new 400,000 volt overhead line north of Hadleigh and Boxford before continuing south-west towards Twinstead.
Corridor 4
Option 4 is to route the new 400,000 volt overhead line in a north-western arc, heading north of Elmsett and Lindsey Tye and Edwardstone before heading south towards Twinstead.
The story so far
We completed our first series of public consultation events in February 2010. Following this we carefully considered all the feedback received.
The feedback from local authorities and local interest groups asked us to provide more information about HVDC technology, overhead power lines and underground cables.
In response to this feedback we published more information about the technical issues involved in building overhead lines and underground cables and explained the background to our proposals in more detail.
We also held a further five public information events where residents were able to view our proposals again and talk to project team representatives.
If you would like to provide feedback on the additional technical information provided, this will be considered alongside the feedback already received.