Report on the Proposed

SE Metro Transmission Project

Red Rock – Wilson Double Circuit

115 kV Transmission Line

 

Prepared by David Schoengold

MSB Energy Associates

March 15, 2001

 

 

Introduction

 

MSB Energy Associates has been asked by the Power Line Task Force to review the proposal by Xcel Energy to add a second circuit to the existing Red Rock-Wilson 115 kV transmission line.  MSB Energy Associates is a consulting firm based in Middleton, Wisconsin with a great deal of experience analyzing and reviewing utility power plans – both for power generation and transmission.  We have attached an appendix which sets forth our experience in this area.

 

We have focused our review on the report prepared by Commonwealth Associates, Inc. titled “Independent Review of Double Circuiting Xcel Energy Red Rock-Wilson 115 kV Transmission Line,” (January 3, 2001).   The characterization of the report as “independent” comes from Commonwealth Associates (CAI).  There have been serious concerns raised as to the true independence of CAI.  CAI was Xcel’s choice for this review, and CAI also apparently has a contract with Xcel to work on the design of the proposed double circuiting.  While we do not necessarily believe that these ties between CAI and Xcel render the report automatically biased, we would have preferred that the independent review be performed by someone who did not have what appears to be an interest in having the review support Xcel’s position.  Nevertheless, the report stands on its own, and it must be reviewed based on what is in it and not on who prepared it.

 

Our report has six sections, focusing on what we believe are the key elements of the CAI Report.  These sections are as follows:

 

·        The need for the line

·        The analytical methods used by CAI to evaluate alternate proposals

·        Alternative routes

·        Proposed design of the double circuit line

·        EMF field considerations

·        Miscellaneous issues

 

 

 

 

 

 

Need for the Line

 

Single versus Double Contingency Planning

 

According to the CAI Report, planning for the proposed line is based on double contingency transmission planning.  Under double contingency planning, the transmission system is required to be able to avoid emergency conditions with two key facilities out of service.  It is important to note that this is not the typical transmission planning standard.  The Mid-Continent Area Power Pool (MAPP) to which Xcel belongs uses a transmission planning standard of single contingency planning – that is, the system should be able to avoid emergency conditions with one key facility out of service.  The CAI Report states that Xcel believes the conditions in the Minneapolis-St. Paul metropolitan area support the use of double contingency planning.  However, no justification is provided for the use of this more stringent requirement.  The choice of the planning standard to be used has a significant impact on the system choices made.  It may well be the case that, under traditional single contingency planning, the proposed project might not be needed at all.  The choice of double contingency planning as a target needs more justification than simply the statement that it is being used.

 

Load Forecasts

 

The need for any type of electric utility facility is based on the forecast of the need for power.  This proposal is no different.  Table 2.1 of the CAI Report sets forth the forecasts used in the CAI analysis.  Below we have excerpted the key elements of Table 2.1.  This table shows the forecasted loads for 2004 as prepared by NSP (now Xcel), MAPP, and CAI, on the substations affected by the Red Rock-Wilson line.  The values shown in the table are in MVA (mega-volt amperes – a unit similar to megawatts but used more commonly in transmission planning).

 

 

Substation                  NSP-2004                  MAPP-2004              CAI-2004      

Stockyards                 66.9                            56.6                            66.9

Rogers Lake              66.4                            51.5                            66.4

Lone Oak                   76.2                            52.8                            80.0

Airport                        64.8                            38.6                            64.8   

Bloomington              84.3                            83.2                            110.7

 

Total                            358.6                          282.7                          408.8

 

 

According to the CAI Report, the NSP forecast is from February 2000, while the MAPP forecast is from April 2000.  CAI has taken NSP’s earlier forecast and increased it to come up with a forecast which is 44% higher than the MAPP forecast for 2004 and 13% higher than the NSP forecast for 2004.  It appears that a large part of the perceived need for this transmission facility is driven by these dramatically increased forecasts.  CAI states in the Report that the forecasted loads were adjusted for an additional 25 MW load at Lone Oak and load increases at Bloomington.  However, the differences between the CAI 2004 forecast at Lone Oak and any of the other forecasts do not equal 25 MW.  Also, a 26 MVA increase in the forecast at Bloomington should be identified by more than just the statement that there is increased load.

 

 

What is the Real System Problem?

 

A serious difficulty with the CAI Report is that it never sets forth clearly what the problems are with the existing transmission system.  As a result, it becomes very difficult to review whether the proposed double circuiting of the Red Rock-Wilson line is the appropriate solution or not.  Our best take on what is going on is that in the general South East Metro area there are strong sources at Red Rock (the 345 kV system), High Bridge (a large power plant), and Black Dog (also a large power plant).  Black Dog is strongly tied to Wilson, and less strongly tied to Bloomington and Airport.  High Bridge appears to be only weakly tied to these substations.  Red Rock is tied strongly to the eastern side of the area, but not the western side.  Xcel seems to want to increase the strength of supply to the Bloomington and Airport areas.  Based on a review of the system maps and interconnections, it seems that there would be things that could be done which would more directly address the apparent problems.  Rather than bring in a stringer source from the east (Red Rock), it appears to make more sense to use the strong sources in the western area (High Bridge and Black Dog) and strengthen the ties between those sources and the Bloomington and Airport areas. 

 

It does not appear that CAI seriously considered alternatives of this nature.

 

Competitive Considerations

 

The CAI Report brings in an interesting statement from the Xcel Planning Summary Report of April 2000.  CAI lists as one of the issues in Xcel’s planning (this may be a direct quote from the Xcel Report – it is not clear)

 

Independence from Generation Supply – Providing a delivery system that is independent of the generation supply location is important because of the dynamic energy sourcing market and the vertical restructuring occurring in the electric utility industry.  Load flow cases were studied without the local generation resources to assess the adequacy of the delivery system.

 

We find this statement to be very revealing.  Essentially, CAI is saying that the transmission system is being designed so as to support competition and restructuring of the electric utilities.  This suggests that the electrical reasons for transmission system development may be less important than the competitive reasons.  It is perfectly reasonable to design and build transmission facilities to support competition.  However, this is a different purpose than the traditional basis for building transmission.  Traditionally, transmission was designed and built for the general public good of providing a network capable of providing reliable electric service to everyone.  Transmission designed and built for the purpose of bolstering competition is not necessarily transmission for a public benefit.  Instead, it bolsters a private good – the competitive positioning of the various players in the electric power industry.  If transmission is being built as a private good rather than as a public good, we do not see why the public should be forced to accept the placement of those facilities on their property.

 

Analytical Basis of the CAI Report

 

The CAI Report does not provide a long-term look at the best way of meeting the transmission needs in the South East Metro area.  Proper transmission planning would look at the projected needs over a period of time into the future, develop alternative approaches to solving problems which occur over that time period, and select the overall approach which solves the problems over the planning period at the lowest cost (including environmental and other non-dollar costs).  If such an approach is followed, the utility can be reasonably sure that it has a good set of solutions to the transmission system needs. 

 

None of this was done in the CAI Report.  The report looks at a single small problem area in a single year.  All we have are CAI’s selection of several alternatives which meet the single problem they focused on.  We cannot tell from the CAI Report whether the proposed line will solve the perceived problem for a short time or a long time.  We also can’t tell whether any of the alternatives considered by CAI might do a better job of solving the perceived problem than the proposal.  For example, it may well be that, having double circuited the Red Rock-Wilson line, Xcel may have to come back in a few years and do one or more of the other proposed alternatives.  In contrast, it might be that if Xcel chose one of the other alternatives, it might well turn out to be a longer lived solution.  We can’t tell, and we suspect that CAI and Xcel also do not know, because the work was not done.

 

Alternative Routes

 

In its review of alternative routes, CAI determined that only routes generally in the Red Rock-Wilson area would be considered.  This placed a severe limitation on their route review.  The net result is that the review of alternative routes provides little or no useful information for the planning process.  With limited resources we have not been able to do the development and review of alternative routes which should have been done by Xcel and CAI.

 

Line Design Considerations

 

According to the CAI Report, the proposed double circuiting will use 795 kcmil conductors.  This is a large conductor size.  It is unusually large for a 115 kV transmission line.  The current carrying capability of these conductors is about twice that of the more typical conductors used for a line of its voltage.  We agree that there are some advantages from using a large conductor size.  The increased current carrying capability is one of them.  Another advantage is that losses are reduced. 

 

There are, however, disadvantages of using large conductors.  One is that the larger conductors are heavier and thus require stronger transmission poles.  These stronger poles will be of necessity more intrusive on the neighborhoods they are placed in.  Another disadvantage is that the higher currents which the larger lines will be able to carry will lead to higher electrical and magnetic fields in the neighborhood of the line. 

 

There is also a potential disadvantage of larger conductors to the area the line passes through.  If the line is built to the same standards as a higher voltage line except for the transformers which determine the line’s voltage, it becomes easier to upgrade the line to a higher voltage at some future time.  Rather than have to add new conductors, the utility only needs to change transformers.  This means that a line which has been built with larger conductors has a higher probability of being increased to a higher voltage than a line which has been built with smaller conductors.

 

 

Electric and Magnetic Fields

 

Current Levels

 

Neighbors of the existing Red Rock-Wilson transmission line are concerned with the health impacts of electric and magnetic fields (EMF).  The CAI Report does nothing to assuage that concern.  Rather, it suggests that the lines neighbors have reason to be concerned.

 

The EMF field levels calculated by CAI for the existing line are extraordinarily high for a transmission line.  And the calculations underestimate the fields affecting many of the line’s neighbors. 

 

·        The CAI calculations use the average height of the line above ground.  A transmission line sags from tower to low point and then goes back up to the next tower.  Residences at the low point of the sag will have greater EMF impacts than are calculated for the average height.

·        A number of residences are closer to the line that the values used by CAI.  These residences will receive higher levels of EMF.

·        The CAI calculations focus on a height of three  feet above the ground.  Residences close to the line will have heights much greater than three feet.  The three foot calculations are of limited value.

 

The CAI Report shows magnetic fields 20 feet from the line at a height of 12 feet of 166 milliGauss (mG).  This is a very high level.

 

 

 

 

Impacts of High Levels of EMF

 

The science of the impacts of EMF fields had been uncertain in recent years.  Earlier studies seemed to show serious impacts from EMF fields.  Then, for a while, studies seemed to be showing that modest levels of EMF did not seem to have serious impacts.  We emphasize the word modest, because we want to make clear that in the case of the existing line we are not talking about modest levels of EMF.  Now, more recent studies seem to be indicating that there are more impacts of EMF than we believed to be the case a few years ago.  Currently the science is not completely definitive on the impact of modest levels of EMF fields.  We note, however, that Public Service Commissions like the Wisconsin PSC have ordered utilities to design facilities to minimize EMF levels so as to minimize the possibility of people being harmed.

 

Again, however, we must reiterate that none of the science has suggested that the high levels of EMF from the existing line are harmless.

 

What is the Relevance of the Level of EMF from the Current Line?

 

The question might be raised as to the relevance of the EMF from the existing lines.  For example, the double circuited line may have EMF fields lower than the current line.  It is often possible to design a double circuit line so that the EMF fields from the two circuits counter each other.  However, we cannot tell from the CAI Report just what the EMF fields may be from the double circuited line, since the report does not calculate the fields for the case where a residence is close to the line (for example, 20 feet), at a height of 12-15 feet, with high currents flowing through the line (for example, 800 amps on each circuit).  While the EMF under those circumstances may be somewhat lower than current levels, we cannot tell how much lower. 

 

An alternative which should have been analyzed by CAI would have included the removal of the current line.   We have been told that part of CAI’s instructions were to consider the case of removal.  There was no analysis of a removal option.

 

Miscellaneous Issues

 

There are several miscellaneous issues to be addressed.  These are in the nature of comments on the CAI Report.

 

Photo Simulations

 

While we cannot make a judgement as to the accuracy of the photo simulations which CAI prepared to show how the proposed double circuiting would look, we can comment on the photos they have prepared.  It seems to us that the photo simulations show a great deal of visual impact form the proposed double circuiting.  The larger, taller towers with the larger lines are much more noticeable than the current facilities.

 

 

Minnesota Department of Transportation

 

We believe that the statements made in the body of the report which purport to summarize the position set forth by the Minnesota Department of Transportation, based on meetings held with the DOT, are misleading.  It seemed to us, reading the meeting minutes, that the Minnesota DOT was more open to the idea of corridor sharing than CAI suggests in its summary.

 

Property Values

 

CAI states that the surveys do not support the idea that the presence of transmission facilities has a negative impact on property values.  While the whole question of property values is being addressed by others, we feel it is necessary to state that, contrary to CAI’s summary position, the data provided by CAI in the report suggests that there is, in fact, a negative impact on property values.

 

Conclusions

 

For the most part the CAI Report is too limited in what it looks at and what alternatives were considered to be very useful as an analytical tool.  However, there is enough in the report to raise serious concerns over the need for and impacts of the proposed project.


Appendix – Background of David Schoengold and MSB Energy Associates

 

MSB Energy Associates has a great deal of experience analyzing and evaluating electric utility proposals, both generation and transmission.  MSB has reviewed utility transmission proposals in South Carolina, Pennsylvania, Michigan, New Jersey, Ohio, Illinois, Arkansas, Wisconsin, and Minnesota.  Recent transmission reviews have included taking part in the Wisconsin Transmission Planning Collaborative, reviewing the Chisago-Apple River proposed line in Minnesota and Wisconsin, and reviewing the Arrowhead-Weston proposed line in Wisconsin.  MSB was founded in 1988, and transmission review has been part of our work from the beginning.

 

David Schoengold is a Principal and a Co-Founder of MSB Energy Associates.  He has worked in the area of utility planning and regulation for over 25 years, including 14 years with the Wisconsin Public Service Commission where he was the Director of System Planning and 11 years with MSB Energy Associates.   A copy of his Vita is attached.