Part Right, Part Wrong
Reconductoring is a good thing, but not enough to solve all (or even many) of the grid issues. As we know it substitutes larger wire for the existing wire.
Traditionally it does not replace substation transformers, protection equipment, or other items on the grid. If the constraint is the conductor (wire) then it works great, but in many cases it is the limits of the service transformers (green boxes in your yard) or the substation transformers. Both right now are on 150+ week lead times (Thank you Jennifer Granholm).
If it is switches and other protective equipment, lead times might be 2 years or more.
Then there is the shortage of Linemen who do the reconductoring.
To do the job right, it starts with rebuilding the substation (and may require rebuilding the sub-transmission and/or transmission) to provide the nameplate capacity to support reconductoring. It may require replacement of poles or conduit to handle the larger/heavier conductor.
Many existing lines are built with 4/0 (four aught) and will handle 400 amps, reconductoring the the largest common size of conductor 1590 increases capacity by a factor of 3 (1200 amps) and increases the weight of the line by a factor of 8. It also is a much harder line to handle when installing and needs more splices (it is bigger so less fits on a spool).
Many utilities are already moving away from 4/0 to 477 and 795, which limits the future improvement without upgrading voltage - a complex process that does not need new rights of way, but can increase the capacity by a factor of 7 (5 kV to 35 kV) and can be combined with reconductoring.
Reconductoring is a no regrets step in the transition of the grid, but it is one tool in the tool box.
Doug Houseman
Expert Member
Top Contributor