CSC: DO 217 Dissenting Opinion Ashton

DOCKET NO. 217 - Northeast Utilities Service Company application for a Certificate of Environmental Compatibility and Public Need for the construction of a 345-kV electric transmission line and reconstruction of an existing 115-kV electric transmission line between Connecticut Light and Power Company's Plumtree Substation in Bethel, through the Towns of Redding, Weston, and Wilton, and to Norwalk Substation in Norwalk, Connecticut.








18 July 2003

11 September 2003)

Dissenting Opinion

Docket 217 involves the proposal for a major reinforcement of the electric transmission system supplying southwest Connecticut and the Norwalk-Stamford sub-area. Specifically, the applicant, Northeast Utilities Service Company acting as agent for The Connecticut Light and Power Company, seeks approval for the construction of an overhead 345kV transmission line from the Plumtree Substation in Bethel south to the Norwalk Substation in Norwalk, a distance of just over 20 miles.

Late in the long and controversial history of this application, the applicant and four of the five affected towns (Bethel, Redding, Wilton and Weston, but excluding Norwalk) filed a joint settlement proposal with the Council. This, in brief, involved constructing a 345kV line consisting of a 1.6 mile underground segment in the vicinity of the Bethel education park and another underground segment, 9.6 miles long, from Archers Lane in Redding to Norwalk Junction. The balance of the line would be overhead. Each of the underground segments would be comprised of two 345kV cables in parallel to match the capacity of the overhead line. This arrangement became known as "Configuration X".

The majority of the Council accepted Configuration X, modified by extending the underground cables 0.6 miles northward from the Bethel education park to the Plumtree Substation and requiring that the 115kV Norwalk-Peaceable line be underground from Norwalk Junction to Norwalk Substation. It is my opinion that, if Configuration X is to be accepted (which I believe it should not, as will be explained), these changes are appropriate and should eliminate any reasonable objection by Norwalk for not being a part of the joint settlement.

Council member Brian J. Emerick has cast a dissenting vote and written a separate opinion to explain his rationale. I join in that opinion and herewith offer further reasoning as to why I also dissent from the majority.

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Need: While I dissent from the final vote of the majority, I strongly support the case to expand the 345kV system to Norwalk. For decades, this section of the State has seen load growth consistently above the State as a whole. That such an expansion is part of a long range plan is undeniable. The construction of the 345kV line from Long Mountain Substation in New Milford to Plumtree approved in Docket 5 in the mid-1970s was explicitly part of a plan to construct a 345kV loop down to Norwalk and then on to the center of the State.

The logic behind such a proposal is rooted in the simple fact that 345kV, the highest transmission voltage in southern New England and New York, is the most efficient way of transporting large blocks of electrical energy. In an attempt to temporize or to mollify opposition to such a high voltage line in this Docket, recommendations were made to rely variously on conservation, distributed generation, or further 115kV expansion. Conservation has already delayed the need for new transmission, but the load has continued to grow. Distributed generation is (largely) an inefficient and expensive solution not really practical at this time with its own serious difficulties. Solutions at 115kV simply will not work: they ignore the serious problems of short circuit duty, contingent overloads and voltage collapse, transient stability, and the fact that virtually all of the existing generation in the area is approaching the end of its economic life. To meet future electrical needs, this generation will eventually be retired and replaced with larger units of much higher efficiency (e.g., combined cycle generation) which is considerably less polluting. Only a strong 345kV network makes this possible. The current and growing problem of economic "congestion" in electric supply within the area would also best be eliminated by a 345kV solution.

Unless and until the State of Connecticut or the individual towns take draconian measures to halt growth in this roughly one-third of the State, we must be prepared to realistically face the need to expand its reliable and economic supply of electricity. The need for the proposed facility is amply justified, and in this I believe all members of the Council agree.

Alternative 345 kV Solutions: In the course of hearings on this Docket, the applicant offered a number of different structural configurations in addition to the vertically arranged 345/115kV structures originally proposed which created a storm of opposition because of their visibility above the tree line. These included the so-called delta and H-frame arrangements which necessitated either undergrounding or reconstructing the existing 115kV line with some widening the right-of-way. These arrangements could be further modified by the use of high-strength conductors (to reduce line sag and hence structure height) or restrained insulators (to reduce lateral clearance and right-of-way widening) Each of these alternatives would reduce visibility but would increase cost to some extent. Finally, undergrounding of 345kV was considered which would eliminate visibility, but at a much higher cost and with major technical problems requiring special consideration.

All of the overhead solutions would create a simple, high capacity line segment extending 345kV to Norwalk. I find it very regrettable that the applicant did not recognize that the proposed construction would be a major source of controversy and give much more thought to imaginative overhead options which would reduce the visual impacts, the dominant environmental effect. In stark contrast, undergrounding 345kV requires two cables in parallel to achieve the same line capacity. As the record amply demonstrates, world-wide practice is to underground high voltage transmission lines when and only where there is no practical alternative (e.g., demolition of obstructions). Such is not the case in this instance. There is sound logic behind this practice. High voltage cables are extremely expensive, typically 2 to 3 times the cost of overhead. High voltage cables also have very high charging current ("capacitive MVARs") per mile which can limit the capacity of the cable to carry load current, can require reactors to compensate for the charging effect, can cause higher than desired voltages during periods of light load, and can potentially lead to increased risk of dynamic and transient instability of generation. Once installed, underground cables are very expensive to relocate if needed, and, if a fault occurs, repairs are very complex and time consuming. All this is in sharp contrast to low voltage distribution (5-23kV) which is frequently undergrounded because the costs much more closely match that of overhead, where repair or relocation is relatively simple, and where the benefits of undergrounding (e.g., unproved reliability, lack of visibility, elimination of tree trimming, etc.) are substantial.

Undergrounding becomes even more complicated when it is done in series with an overhead line, and worse still when this pattern repeats multiple times ("porpoising"). High voltage lines experience significant overvoltages caused by both lightning and from operation of switches in the line. These overvoltages can double at points where there are discontinuities along the line, especially where there is a transition from overhead to underground, and can stress the cable insulation to the point of failure. Additionally, the electrical control and protection of a line containing both cable and overhead construction becomes very complicated. A simple overhead line is very straightforward: protective relaying on the line can readily determine the location of a fault, trip the line, and, if a transient fault exists (such as from lightning as is most common), initiate reclosing in less than a second. With an underground line, or both underground and overhead, reclosing is not an option for risk of severe damage to the cable portion. It gets worse if two cables are in parallel: which cable is faulted? If the line is terminated in a single circuit breaker (or set of breakers), the location of the fault is unknown and the line must be carefully tested, requiring a long outage, before being returned to service. The only option to minimize (not eliminate) this problem is to terminate each cable segment in a circuit breaker. This is a very expensive solution at 345kV and would make the large (about 1acre) terminal stations even larger. It would, however, make it practical to take one cable of two in parallel out of service during the 60-80 percent of time when area loads are light and cable charging current creates system voltages higher than desired. While practical, it is not desirable to deliberately reduce the capacity of the transmission system by half.

Realistically, there are two types of 345kV cable available for consideration in this country: high-pressure fluid-filled (HPFF) and cross-linked polyethylene (XLPE). HPFF has had wide use at voltages below 345kV, but relatively little at that voltage. The majority is located in a few urban centers, especially New York City, with the longest line being about 20 miles. XLPE, widely used now at 115kV and below, is a newcomer at 345kV or above. Worldwide, there are few installations and then only in the past 5 years or so. The reliability of HPFF is comparable to that of overhead but that of XLPE is much worse, especially for failure of splices. Repair to both types is very time-consuming and extremely exacting. On the other hand, the large volume of insulating fluid in HPFF poses a potential risk even though it is not toxic; XLPE contains no such fluid having a solid extruded insulating system. It is all well and good to state that we (i.e., Connecticut and CL&P) should use 345kV XLPE cable as exemplifying progress in the new 21st century, but such action places the electric supply to southwestern Connecticut at enormous risk, quite unjustifiably.

The Settlement: The joint settlement (configuration X) proposed by CL&P and the four towns presents the Council with a dilemma. The Siting Council is charged by statute with "balancing the need for adequate and reliable public utility services at the lowest reasonable cost to consumers with the need to protect the environment and ecology of the state", etc. This continuously poses the need for the wisdom of Solomon in making decisions based upon, in this case, a very extensive record with frequently conflicting points of view and numerous options. Professor Tait states in his concurring opinion: "(t)he law generally favors compromises between parties to a civil suit, but unlike private litigation -, this is not a civil case but a proceeding held before a public agency that has statutory responsibilities which cannot be ignored , and any solution must be tested by the statutory criteria. However, the fact that (configuration X) is a good faith effort to resolve complex and contentious issues should not be ignored." I certainly share this belief, but would emphasize that no "compromise" should be binding on the Council, given our statutory obligation. In fact, the majority of the Council did not accept the settlement, but modified it in the vicinity of Plumtree and the approach to Norwalk Substations. In so doing, they took a system configuration which was- a technical nightmare (if not impossibility) and created one I believe unreasonably difficult, expensive and without justification.

First, I believe the applicant, in attempting to resolve the controversy surrounding this Docket, accepted a solution in the settlement which is truly a technical nightmare. The mix of HPFF and XLPE, grudgingly acknowledged by the applicant's witness (contrary to earlier testimony) as being reliable, creates severe operating problems (supra). Further, I cannot justify the use of underground in the vicinity of the Bethel education park nor in much of the remaining route chosen for underground where options for overhead exist

without significant adverse environmental effect. Two motives may have influenced the applicant to accept this decision: the need to complete the line by 2006 to meet load growth, and the fact that the Federal Energy Regulatory Commission (FERC), which has the ultimate authority to determine how the cost of transmission facilities will be recovered, has stated that it will allow the costs of "a defined set of transmission upgrades into SWCT" to be spread among customers (i.e., "socialized") throughout New England provided that such upgrades are placed in service by December 20, 2007. Significantly, it is unclear that all costs of upgrades, including those not normally or reasonably incurred in system expansion, are covered. Thus, the disposition of the extra costs (about $68-73 million "not inlcuding the cost of necessary shunt reactors" (See Note 1)) resulting from the settlement is unclear. They may well be dumped upon Connecticut ratepayers if NEPOOL or FERC refuses to accept them. The 2006 in service date is more troubling to me, but I suspect the state of the present economy and its impact upon electric load may well make a later deadline possible, albeit not much later.

The towns, in my opinion, missed a golden chance to significantly improve the landscape as viewed by many as opposed to a relative few. They could and should have pressed CL&P for a much advanced policy on the undergrounding of distribution running on local streets. The costs here, where reconstruction is forced by load growth or for highway construction, is much closer to that of overhead. And the benefits, primarily visual and in reliability, are significant. The technology of underground distribution is excellent and this is where I strongly feel the State and CL&P should step into the 21st century. I readily acknowledge that this Council now has no jurisdiction over distribution (as defined). However, I do believe that this sort of settlement, if one is required, is in the long range interests of all the State.

Thus, I believe that the settlement fails from both perspectives and will prove to be a faustian bargain. The mix of underground and very tall overhead structures adopted by the settlement is unacceptable to me from both an environmental and technical standpoint. Two wrongs do not make a right and the unresolved issue of the extra costs may well prove to be a third wrong.

Philip T. Ashton



Note 1: In the earlier version of this dissenting opinion, these "extra costs" were stated to be "about $40-45 million". This dissent has been updated to reflect the revised Opinion adopted by the Council on 9 September 2003. No other change has been made herin. The revised data effectively doubles the "extra costs" and makes the modified settlement, and the opinion and decision of the majority of the Council endorsing it, even more unreasonable.

Content Last Modified on 9/22/2003 11:16:44 AM