Why PJM Is Wrong About PATH

We now have clear testimony on record in East Virginia by nationally recognized, independent electrical engineers about PJM Interconnection’s claims that the PATH line is needed.  That independent testimony has clearly demonstrated that PJM is wrong.  The experts also show that even if PJM were right about the problems they identify, all of those problems could be solved more quickly and at much lower cost than building a huge new transmission line.

Here is what these independent experts said in their testimony to the VA SCC.

Electrical engineer Hyde Merrill’s opening summary:

PJM’s planning studies do not justify the PATH line. The vast majority of alleged reliability issues that are presented in support of the PATH line are not based on any modeling or contingency analyses as NERC requires. None of the alleged violations is based on reasonable assumptions regarding the need for power transfer from western to eastern PJM — i.e. reasonable Capacity Emergency Transfer Objective (“CETO”) values. And even if the alleged violations were based on credible analysis — which they are not — none of them creates a present need to build the proposed PATH line.  Rejecting PATH now will allow time to develop far better alternatives for the evolution of the power system within PJM’s boundaries.

In contrast, approving this line will lead to increasing reliance by the East Coast on remote coal-fired power plants with continuing or increasing transmission congestion, transmission losses, and a greater risk of cascading blackouts.

Merrill directly addresses all of the problems that PJM claims will develop if PATH is not built.  These problems include:

  1. Voltage collapse and instability on current lines.
  2. Overheating (thermal violations) of equipment on smaller transmission lines that violates standards set by the North American Electrical Reliability Council (NERC)
  3. Overheating of equipment on larger 500 kV transmission lines that violates NERC standards.

Voltage instability is eliminated by adding large capacitors to the grid to regulate voltage levels and control reactive power needed to stabilize the voltages of current flowing through the system.  Mvars, or mega vars, are units of reactive power called “volt amps reactive.”  These are distinct from watts that are used to measure normal current.  Because these capacitors regulate reactive power, their output is measured in Mvars.

Merrill states that all of PJM’s claimed problems can be solved by adding capacitors without a new power line.

PJM’s claimed vulnerability to widespread voltage collapse was identified for the first time in April 2009, long after the line had been approved based on alleged 500-kV thermal violations. Now, PJM maintains that PATH is required to prevent alleged voltage collapse. However, PJM has admitted that installing 2,000 Mvars of capacitors would eliminate these voltage issues. And Company witnesses have admitted that the PATH project itself entails installation of 1,750 Mvars worth of new capacitors. In other words, PJM has identified a need to install new capacitors with or without the PATH line in service. So why not install PJM’s 2,000 Mvars of capacitors, costing $40 million, instead of the planned-for 1,750 Mvar and the $1.8 billion PATH project?

And later:

In any case, voltage issues on the scale of the alleged violations presented by PJM can and should be resolved by installing new capacitors, not by building a new 765-kv power line.  PJM claims that a conventional remedy, compensation with capacitors, is impractical due to the “sheer number” and cost of about 2,000 Mvar of capacitors that PJM says would solve the alleged voltage problems. PJM also claims that capacitive compensation will make the system harder to operate. These objections are invalid. Again, PJM proposes to install 1,750 Mvar of capacitors as part of the PATH project.  Building the PATH line will not avoid installing the
capacitors that PJM claims are an “infeasible” alternative.

Merrill points out that any reference to voltage instability as a reason for building PATH appeared for the first time in PJM’s 2009 transmission plan.  Merrill can only guess that this new surprise problem appeared because PJM had changed its planning assumptions.  However, PJM did not reveal either its planning assumptions or any changes in them, so PJM has given no reason why voltage stability was never mentioned in 2007 and 2008 reports but appeared for the first time in 2009.

Here is how Merrill assesses the thermal violations that PJM identified on lower voltage transmission lines.  I have left the attorney’s questions in this extended quote to provide a point of reference.  Mr. McGlynn is a PJM engineer who provided testimony in support of the PATH line.

A: The alleged thermal issues relating to lower voltage line are identified for the first time in the April 2009 Retool Study, and they appear in the first six rows of Exhibit PFM-2 to Mr. McGlynn’s testimony. These are the only thermal violations that are alleged to appear in 2014, the last year in which PJM performed contingency and other formal analyses to evaluate reliability, as will be shown in Section IV below discussing alleged 500-kV thermal issues.
A: No. These alleged problems are associated with the lower-voltage system. PJM resolves many such problems every year without building 765-kV lines. It is not reasonable to build a 765-kV line to resolve issues that can be addressed with routine fixes that are far less costly, far less intrusive, and in some cases, more effective than the proposed PATH line. PATH is overkill as a solution for four of these six purported issues. According to PJM, PATH is only a temporary fix for the other two.

Merrill goes on to point out that these alleged thermal violations are the only problems that PJM claims will happen in 2014, the earliest date they claim PATH will be needed.  All of the other “problems” PJM uses to justify PATH are not based on computer simulations, but on “extrapolations” of calculations done for the years up to 2014.  In other words, all of the problems in 2014 are minor problems on low level transmission lines that can be resolved easily as local problems.

All of PJM’s other “problems” are not even based on the dubious computer simulations that PJM uses.  Those other thermal violations and voltage instability are predicted only by “extrapolations” from the pre-2014 models.  As Merrill points out later in his testimony, these extrapolations are little more that guesses:

Extrapolation rather than detailed model[ing] is notoriously inaccurate. A $1.8 billion line should not be based on such a flimsy foundation.  Here, all extrapolated results are based on an inaccurate 2014 power flow base case.  After 2014, PJM does not alter the base case to reflect new generation projects or DSM [demand side management] resources in the mid-Atlantic [area.]

The “power flow base case” refers to the estimated flows of electricity under peak load conditions through the circuits that PJM was studying under current conditions without PATH or any other alternative.  Here is what expert George Loehr said about PJM’s power flow estimates in his VA testimony:

• In my view, the Load Deliverability procedure used by PJM comes up with Capacity Emergency Transfer Objective (CETO) values that are unnecessarily high, and seems out of synch with what the rest of the industry is doing. There are better, more systematic and technically consistent ways to determine the import capabilities required by Load Deliverability Areas (LDAs) to maintain reliability.
• Without PATH, the capability of the Mid-Atlantic LDA to import power would still be in excess of 6,000 MW. In other words, with a 6,000 MW transfer into the Mid-Atlantic area, there would be no reliability violations. Not one.
• In my opinion, NERC violations have not been established since the base case assumptions are too conservative. So, too, are the CETO/Load Deliverability procedures.
• PJM’s procedure for establishing CETO values is far more conservative than other eastern ISO/RTOs. It’s ultra-conservative when compared to New York and New England.
• In general, the PJM process for assessing reliability and determining “need” seems to favor extreme solutions – solutions far more massive than necessary.  This overkill approach violates an important engineering principle: “Don’t use a pile driver to hammer tacks.

Merrill’s analysis of PJM’s predicted thermal violations on larger existing 500 kV lines is completely dependent on PJM’s extreme power flow estimates and the fact that they all occur after 2014 when PJM is just using guess work as the basis for its predictions.

Merrill concludes that if proper power flow estimates are used, all the higher voltage violations disappear or are pushed so far into the future that as to be meaningless for current planning purposes.

Finally, Merrill and Loehr both point to the fact that after 2014, when PJM’s engineers rely on “extrapolation,” the PJM projections do not take into account any reductions in power flows as a result of demand management and efficiency improvements.  None of PJM’s projections after 2014 take into account any new power generation on the east coast that would reduce these power flows even further.

Merrill and Loehr conclude that just using the proper power flow estimates, as used by all the other regional transmission organizations in the US, all of PJM’s claimed problems in the next 15 years would disappear.

Here is Loehr’s conclusion:

A. Not at all. Whether or not violations will occur ultimately depends on the value selected for the CETO. This applies to voltage as well as line loading violations. There would be no violations of NERC Standards if realistic CETO values were used. The only reason that “violations” were identified in PJM’s studies is that PJM was trying to cram too much power from outside (essentially western PJM) into the eastern LDAs by using unnecessarily high CETO values. It’s sort of like a mouse trying to swallow a lion. For the Mid-Atlantic LDA, without PATH, a 6,000 MW CETO would result in zero violations. Zero. And the Mid-Atlantic area would still be capable of importing over 6,000 MW.