Methanolic Corrosion of Aluminum

Inquiry

I understand that there was some issue with CableCURE^®/XL fluid when deployed in Germany in aluminum stranded cables. How do Novinium’s Ultrinium 732 or 733 fluids interact with aluminum stranded cables?

Response

It is true that about 1% of cables treated in Germany in 2002 with CableCURE/XL fluid failed because of the methanolic corrosion of aluminum. Even though the incidence of failures was quite low, the failure mode was dramatic as illustrated nearby. See the image labeled “German Cable Failure” taken from Bertini, “Failures in Silicone-treated German Cables Due to an unusual Aluminum-Methanol Reaction,” (ICC October 29, 2002). In the illustration the grey material between the strands is aluminum methoxylate, the profuse formation of which caused the insulation to bulge. The bulge is described as similar to when a snake eats a rat. An analgous phenomenon occurs in low voltage cables in the presence of water. In both cases, the bulging occurs because the aluminum hydroxide or aluminum methoxylate has a very low density, or put another way, takes up a great deal of volume. Because rejuvenation is utilized to improve the reliability of power distribution cables, even a 1% induced failure rate is unacceptable.

Novinium was founded in 2003, so we enjoyed the benefit of hindsight into the methanolic corrosion of aluminum and hence we addressed this issue in all of our Ultrinium and Perficio technologies. Novinium has not had a single incident of methanolic aluminum corrosion.

To demonstrate why Novinium technology avoids methanolic corrosion, it is useful to understand the mechanism of methanolic corrosion. One compound and one element are required for methanolic corrosion to occur … the compound is methanol; the element is aluminum.

Compound

CableCURE/XL fluid, Perficio 011 fluid, and Ultrinium 732 fluid all include methoxy silanes, which react with encountered water and produce methanol as a by-product. Ultrinium 733 fluid and CableCURE/DMDB do not produce methanol as by-products, instead these fluids produce larger, less chemically reactive higher boiling point alcohols, namely 2-ethylhexanol and n-butanol.

The reaction of methanol with native aluminum (methoxylation) proceeds at a rate proportional to the concentration of the methanol. The concentration of methanol in the strands of a treated cable is influenced by four factors:

1. The amount of water that is present in the strands and the strand-shield. Less water means less methanol; more water yields more methanol.

2. The stoichiometry of the silane water reaction. Stoichiometry is chemist-speak for the ratios at which materials react. For the CableCURE/XL fluid and Perficio 011 fluids, which utilize the same monomeric silane, the maximum possible methanol concentration is about 25% by weight. For Ultrinium 732 fluid the maximum is about 20% by weight. All other things being equal, Ultrinium would enjoy about a 20% lower methoxylation rate because of the superior stoichiometry.

3. The rate at which methanol diffuses from the strand area out of the cable. The diffusion of methanol is quite fast, so the risk of methoxylation decreases rapidly for all technologies. Higher temperature accelerates the diffusion and dissipation of methanol.

4. The use of non-methanol-based alkoxysilanes reduces methanol concentration beyond the 20% stoichiometric advantage described in factor 2 above. In a patented process (U.S. patent 7,611,748 and its foreign equivalents) Novinium adjusts the formulation with more and more non-methanol-based Ultrinium 733 fluid as the anticipated temperature of the treated cable rises.

Element

Except for copper stranded cables that are immune to methanolic corrosion, at first blush it appears obvious that elemental aluminum is available in an aluminum stranded cable, but it is not. As soon as aluminum strands are drawn and laid into a strand bundle on the factory floor, the outside layer of aluminum reacts with oxygen to form aluminum oxide (Al₂O₃). Aluminum oxide forms a dense barrier that protects the underlying native aluminum metal. This aluminum oxide layer is called a patina and it protects the underlying aluminum from further corrosion.

Patina

If you take a piece of aluminum and scrape off the patina with a knife, you will see bright and shiny native aluminum underneath. In the presence of oxygen, the patina begins to reform immediately. The shiny surface will soon return to its dull grey appearance. Of course, in a power cable there are no knives scraping off the protective patina, so how did the CableCURE/XL fluid penetrate the patina? One problem with CableCURE/XL fluid and CableCURE/DMDB is the use of a condensation catalyst called titanium (IV) isopropoxide.  Also known as tetraisopropyltitanate, we will call it TIP. Over the course of Novinium’s research we learned that TIP facilitates the degradation of the patina. Novinium does not use TIP in its Perficio or Ultrinium formulations. Novinium uses a patented catalyst (U.S. Patent 7,700,871 and its foreign equivalents) that does not suffer the same problem.

A second way that the patina can be damaged is bubble nucleation or boiling. Bubbles form in microscopic cracks in the patina and their rapid expansion and sudden disappearance mechanically perturb the patina. In the discussion above we learned that Ultrinium 732 fluids enjoy about 20% less stoichiometric methanol and hence the boiling point of the mixture is higher. Put another way, it takes a greater temperature escalation for Ultrinium to produce bubble nucleation than for CableCURE/XL and Perficio fluids. The patented silanes (U.S. Patents 7,658,808 and 8,101,034 and their foreign equivalents) included in Ultrinium fluids by Novinium and our partners enjoy improved stoichiometry, mitigating methanolic corrosion. CableCURE/XL fluid is particularly egregious in this dimension, because it includes an ingredient called trimethylmethoxysilane (TMMS) that has a boiling point even lower than methanol. To mitigate the aggressive bubble nucleation of 2002 vintage CableCURE/XL fluid UTILX Corporation reduced the concentration of TMMS in CableCURE/XL by a factor of between 3 and 6. This problem with TMMS is well documented by U.S. Patent Application 2009/0114882 and its international equivalent WO 2006/119196. Besides attacking the patina the TMMS creates a fire and explosion hazard. Novinium does not use TMMS in Ultrinium or Perficio fluids.

In addition to mitigating the causes of patina damage, Novinium utilizes a patina stabilizer from BASF^®, called Tinuvin^® 123 hindered amine light stabilizer. In experiments undertaken at Novinium, Tinuvin 123 outperformed all other patina stabilizers by at least a factor of two. Tinuvin 123 has other beneficial performance attributes to extend cable life and is included in Ultrinium and Perficio fluids and its use is protected by U.S. Patents 7,658,808 and 8,101,034 and their foreign equivalents.  In a patented process (U.S. patent 7,611,748 and its foreign equivalents) Novinium increases the supply of Tinuvin 123 by increasing Ultrinium 212 fluid as the anticipated temperature of the treated cable rises.

Summary 

Novinium substantially reduces the methanol concentration using proprietary silanes, does not use low boiling and highly flammable TMMS demonstrated to cause bubble nucleation even at moderate temperatures, eliminates a patina attacking catalyst utilized in the offending formulations, and adds a patina stabilizing compound to all but prevent methanolic corrosion of aluminum in its Ultrinium formulations. Perficio technology includes the improved catalyst and patina stabilization, and does not use low boiling TMMS. Perficio suffers from a higher methanol concentration than Ultrinium technology. Perficio technology should not be utilized in high temperature aluminum-conductor applications.

Third Party

Dear Alert Amphibian-

Can you provide third party data demonstrating that cable injection will extend the life cycle of underground cables? My colleagues and I are preparing for a rate filing with the OEB and we are looking for some firepower, facts and figures to bolster our case for additional cable injection monies for 2014 and beyond.

Seeking help,

Organizing in Ontario

Dear Organized-

I can think of four “flavors” of third-party data.

Flavor 1

Flavor 1 includes data gathered by third parties at the behest of a firm engaged in rejuvenation. The third party is independent, and is generally working for the technology supplier. There is an ample supply of this type of data, spanning over two-and-a-half decades. As an example of this type of data, consider Figure 3 of the paper published by my colleagues at the IEEE International Symposium on Electrical Insulation in September 2004…

New Developments in Solid Dielectric Life Extension Technology 

Figure 3 shows the substantial improvement in AC break-down performance seven days after injection at Cable Technology Laboratories. There is an abundance similar Flavor 1 third-party data. A compilation of that data can be found in the bibliography presented at the NETA Powertest Electrical Conference on March 17, 2008.

History and Status of Silicone Injection Technology with Bibliography

This paper provides 50 references including flavors 1, 2, and 3 of third-party data.

Flavor 2

The second flavor of third-party data are results reported by end-users. There have been several North American utilities that have reported their post-rejuvenation reliability over multiyear periods. The IEEE’s Insulated Conductor’s Committee (ICC) Discussion Group C30 is compiling several of these case studies as part of its efforts to craft a Guide entitled, “Extending the Life of Power Cables in the Field.” One exemplary data set was published by Northeast Utilities at the spring 2008 ICC. I have attached an excerpt of the ICC meeting minutes below. Over a nine year period from 1999 to 2007, the failure rate of the post-rejuvenated cable was 0.7% and the failure rate of the non-rejuvenated cable was 12%. Novinium’s failure rate is about half of the failure rate enjoyed with this older technology – see flavor 3.

R.Vencus. Cable Injection Program CL-P 2008.pdf (8.13 kb)

Flavor 3

The third flavor of third-party data is the overall failure rate of rejuvenated cables. Circuit owners have an incentive to report their post-injection reliability issues as they get cash for doing so! Novinium transparently publishes these statistics at …

http://www.novinium.com/Lessons.aspx

Novinium’s post rejuvenation failure rate is less than that of new cable! Check out my March 23, 2012 post, “Better Than New” to learn more.

Flavor 4

The fourth flavor of third-party data would be a Coke vs. Pepsi, side-by-side “taste test” of different rejuvenation technologies funded by electrical circuit owners and conducted by a third-party laboratory. There is good news, there is bad news, and some new that falls between good and bad. The good news is such a test was arranged by NEETRAC (National Electric Energy Testing, Research & Applications Center) sponsoring firms including: AEP, BG&E, ConEd, Oncor, FPL, Exelon, Southern Company, PEPCO, Southwire, and Snohomish Public Utility District. The bad news is that only Coke showed up for the taste test! The other technology supplier participated in the experimental design, but withdrew just as the testing was to commence citing, “Business and commercial reasons.” I will leave it for your contemplation why the other guys would not want to participate in a side-by-side test. The test proceeded with Novinium only. The news that is not bad, but not ideal is that even though the test was completed about two years ago, NEETRAC has not yet published the results in anything other than draft form. An excerpt of the draft NEETRAC report provides the bottom line of the testing:

“ … the stress at which the rejuvenated cables fail is higher than for the non rejuvenated cables: 26 kV/mm and 16 kV/mm, respectively. These stresses are taken at the 50^th percentile (median). Moreover, it would appear that the [Novinium] rejuvenated cables have a threshold for failure at 4.5 kV/mm whereas there is no threshold for the Non Rejuvenated cables."

The reported performance advantage was measured after about 18 months of accelerated aging – well beyond the originally planned twelve-month experimental plan. The electrical stress of a typical 175 mil insulated URD cable energized at about 8kV to ground is 1.8kV/mm. The treated failure threshold is 2.5-times typical operating voltages even after extended thermal and electrical accelerated aging.

Ready for any party,

Thermonuclear Frog

Wet, Wetter and Wettest

Dear Soggy Froggy,

I have two areas under consideration for rejuvenation next year.

• The first is a sub-division with 40 year-old cable that is in relatively dry sandy soil.
• The second sub-division has 15-20 year-old cable that is in very wet, swampy soil.

All other things being equal, which area would enjoy the greatest benefit from rejuvenation? Is there any data to support the recommendation? I hypothesize that the cables in the swampy soils should be injected first, since those cables are constantly in water and injecting them might yield the greatest benefit.

Wet, Wetter and Wettest

Dear Wettest-

It’s true that I have a personal preference for the swamp, but I won’t let that predilection alter my advice. This is a really great question because the wetness of the soil at one meter depth is not often discussed and often misunderstood. Fortunately one of my colleagues wrote a paper cited below that unearths the truth of the matter.

Bertini, “Molecular Thermodynamics of Water in Direct-Buried Power Cables,” IEEE Electrical Insulation Magazine, Nov/Dec 2006.

I would encourage my readers to review that paper in its entirety as it dispels many common myths. However, I asked the author to summarize the portion of the paper that relates specifically to your query and he has done so in a YouTube video. Watch this video and learn why both populations of cable are equally wet.

In your inquiry you say, “All other things being equal.” But are they really equal? I would suggest that the first criteria should be: Which of the two areas has had the greatest reliability issues per foot of installed cable? If reliability is equal, I would use age as the next best predictor of future performance.

Forever wet,

Thermo B. Frog

Honesty – Best Policy

Dear ample amphibian-

A gentleman from UTILX says that while he worked for Dow Corning Corporation in the early 1990’s he and his colleagues tested the materials that Novinium uses today and that Dow Corning rejected their use because these materials were second-rate, that is they did not work as well as the PMDMS (or phenylmethyldimethoxysilane), the main ingredient of CableCURE^®/XL fluid.

What say you?

California Dreamer

Dear Dreamer-

There are three assertions being made by an Individual From Competition (IFC) who knows better:

Assertion 1: Dow Corning tested the materials that Novinium uses today,

Assertion 2: The performance of those materials was second-rate in comparison to the main component of CableCURE/XL, namely PMDMS, and

Assertion 3: Even with all the other process and catalyst improvements Novinium has made, Novinium’s fluid remains second-rate.

pieces of eight

by t. b. frog

you are not the first person, to whom this dream has been spun,

i was not even a glimmer in my father’s eye when this work was done;

somebody is indeed dreaming, but it is easy to set the record straight,

consider these pieces, there are eight.

Piece One: Assertion without proof

Let’s say that you had data which demonstrated your competitor’s product was inferior to your own. Wouldn’t you publish it? IFC, come clean … show us the data you purport to possess!

Piece Two: Testimony

To get the straight scoop I went to my colleague, Glen Bertini. Mr. Bertini directed the early work at Dow Corning (circa 1992). He is the guy who conceived of CableCURE/XL fluid, and he is a co-inventor of the materials that Novinium uses today. Mr. Bertini knows that all three of IFC’s assertions are not entirely forthright. The silane materials that Novinium uses today are listed unambiguously on the Ultrinium™ 732 and Ultrinium™ 733 material safety data sheets (MSDS). These materials are …

• tolylethylmethyldimethoxysilane (+ isomer of same & 8-carbon alkoxy analog)

• cyanobutylmethyldimethoxysilane (and 8-carbon alkoxy analog)

Mr. Bertini provides a sworn and notarized declaration (link is nearby) asserting that neither of these materials were tested by Dow Corning or UTILX during the 22-year period from July 1980 to December 2001.

80-20120627_GJB_Declaration.pdf (281.40 kb)

Piece Three: Challenge

Mr. Bertini hereby challenges IFC to a public debate exploring the merits of these assertions. The debate will be recorded in its entirety and provided, unedited on YouTube for the entire world to see and hear. Novinium will bear all of the production costs and will travel to meet IFC at a venue of his choice – any time, anywhere.

Piece Four: Side-by-side taste test – Round I

IFC's employer had an opportunity to demonstrate the superiority of its technology when NEETRAC, NEETRAC’s sponsoring circuit owners, and other NEETRAC-affiliated industry leaders invited UtilX to participate in a side-by-side laboratory experiment together with Novinium. UtilX helped craft an experimental protocol, but withdrew its participation when the experiment was to actually begin. That experiment is complete and included the only rejuvenation firm willing to share their post-injection results in a truly independent experiment – that would be Novinium. UtilX demurred, citing “business and commercial reasons.”

Piece Five: Side-by-side taste test – Round II

If UTILX now regrets that it did not participate in the NEETRAC side-by-side test, Novinium will grant it a Mulligan. Novinium will eagerly participate in a new experiment, which directly compares the post-injection performance of UTILX’s products against Novinium products. It’s not too late to end the debate, but you have to promise not to withdraw at the eleventh hour this time! Novinium will fund the experiment, which will be executed by an independent laboratory with a substantially similar protocol as was previously agreed by UTILX.

Piece Six:  Analogous materials are not second-rate

It should be clear to the critical reader that Novinium’s modern fluids were never tested by Dow Corning or UTILX, but what about the second claim – the claim that the untested materials were second rate? If the materials were never tested, the assertion seems a little silly, but there is another less-than-honest dimension to this second assertion. IFC is suggesting that phenylmethyldimethoxysilane (PMDMS) utilized in CableCURE/XL fluid and Novinium’s own Perficio™ 011 fluid is first-rate or has no peers. Let’s test that assertion against the following statement proffered by UTILX in its paper, “Failures in Silicone-treated German Cables Due to an Unusual Aluminum-Methanol Reaction,” published at the IEEE, PES, ICC in October 2001. To wit …

“In those experiments there was not a statistically significant difference between the performance of methoxy silanes and their ethoxy equivalents. For example, the screening experiments included phenylmethyldimethoxysilane, tolylmethyldimethoxysilane, dimethyldimethoxysilane, and vinylmethyldiethoxysilane, which all had very similar performance profiles. The ultimate choice of the alkoxy group was not driven by performance, but was rather driven by commercial availability.”

PMDMS was chosen because it was cheap and easy to come by! UTILX names several materials for which “there was not a statistically significant difference between the [dielectric] performance” from the PMDMS that IFC now suggest is the one-and-only first-rate performer. The careful reader with some background in chemistry will note a similarity between the named tolylmethyldimethoxysilane and Novinium patented (U.S. 7,658,808 & 8,101,034) tolylethylmethyldimethoxysilane – different only in the two extra methylene units encompassed in the “ethyl.” The two materials are not identical, but they are analogous. The reported data contradict IFC’s second assertion. Novinium has done many experiments with its actual materials and these materials consistently outperform PMDMS. Check out my post of March 15, 2011 to learn how those two methylene units boost post-injection reliability of tolylethylmethyldimethoxysilane using “Chain Entanglement.” But there is more, not only are there unidentified materials in the data published by Dow Corning and reproduced in the illustration nearby, but there are materials which are not disclosed at all. Some unidentified materials performed better than PMDMS. IFC should publish all of the results – even if those results do not support his contentions.

Piece Seven:  Devil in the Details

In the illustration nearby I provide a compilation of data from the two cited sources – both are Dow Corning/UTILX documents. These data are a subset of the data to which IFC is undoubtedly referring when he makes his assertions. As you can see from Mr. Bertini’s Declaration there is even more data, which if it were made public would cast an even darker shadow on the assertions of IFC. It’s interesting data for sure, but it does not support the notion that PMDMS is particularly special. There are a variety of other materials, which show statistically similar performance. But what is the ACBD of the y-axis? It’s the AC breakdown strength (50% probability) after 6 months of immersion in ambient temperature water and 2.5X rated voltage (20 kV). Is that test protocol a good predictor of performance after 20 years? After 40? Of course, not. To suggest so would be like declaring that the horse in first place at the first turn will win the derby. The testing to which IFC refers is a short-term screening experiment and cannot discriminate long-term performance.

Piece Eight:  Overlooking the catalyst

Not only was the experiment woefully short and not thermally accelerated, all of the silanes tested were catalyzed with 0.2%_w titanium(IV) isopropoxide (TIP). Novinium does not use TIP because it suffers from an unacceptably low catalytic efficiency. It’s about 39% inefficient. Novinium’s patented catalyst technology is 98% efficient. See my previous posts on the subject of catalytic efficiency at …

Catalytic Considerations – Component I (January 3, 2011)

Catalytic Considerations – Component II (January 5, 2011)

Novinium’s master scientists have not tested every water reactive material shown in the illustration with our patented catalyst technology, but we have tested all the commercially important ones. Without exception, long-term performance, what I like to call persistence, is substantially improved by the application of Novinium’s U.S. Patent 7,700,871.

There is an old Madison Avenue adage, “If you don’t have anything to say – sing it!” Which of the following do you like the best for the IFC Corollary? (check all that apply)

ü  If you don’t have any facts – wing it!

ü  If the facts don’t support your position – obfuscate!

ü  If you won’t spend money on R&D, cite 20-year-old data out of context!

Finally, I have a selfish appeal directly to IFC, who is one of my most loyal readers. Don’t change your story one iota! The reason that so many circuit owners tell us of your tale, is that it isn’t credible. Send me your comments and I will publish them here unedited.

Credibility is transparency,

T. B. Frog

80-20120627_GJB_Declaration.pdf (281.40 kb)

LIPA

Dear Felicitous Frog-

I have read a paper from the conference record of the 2008 IEEE International Symposium on Electrical Insulation (ISEI) by some folks at Powertech Labs from my home province of British Columbia. The paper was titled: “Condition Assessment of 15 kV Rejuvenated Underground XLPE Cables.” The cables in question are operated with AC, but the testing method is with DC.  Does a DC test have validity on an AC cable? The paper shows results of before-and-after diagnostic testing on two treatment methods, referred to as “method A” and “method B.” Are these results representative of Novinium’s post injection experience?

Currently,

AC in BC

Dear AC-BC:

Other frog fans may wish to review the full text of the paper to which you refer. The paper is available for a small charge from the IEEEXplore^® digital library; click here to view the abstract and full citation. The test method utilized in the paper is the LIpATEST™ technique, proprietary to PowerTech Labs. PowerTech is primarily owned by BC Hydro. The LIPA technique measures the DC leakage current through the cable insulation as a function of applied DC voltage. The 15 kV-class cables described in the paper are subjected to a negative voltage, increased in 4 kV steps of 1-minute duration, to a maximum of 16 kV. The leakage current is recorded at each step. The purveyors purport that the magnitude of the leakage current and its rate of change with applied voltage provide an indication of the quality of the cable insulation.

You asked two questions: Is the test valid and are the results representative? I provide answers to both in four parts, entitled: DC Testing, LIPA Validation, Rejuvenation Methods Tested, and Representative or Not?

DC Testing

The 2001 version of IEEE 400™, “Guide for Field Testing and Evaluation of the Insulation of Shielded Power Cable Systems,” provides some guidance and is available from ANSI. Click here to view the abstract and complete citation. Paragraph 4.2 states in part …

“Whenever dc testing is performed, full consideration should be given to the fact that steady-state direct voltage creates within the insulation systems an electrical field determined by the geometry and conductance of the insulation, whereas under service conditions, alternating voltage creates an electric field determined chiefly by the geometry and dielectric constant (or capacitance) of the insulation. Under ideal, homogeneously uniform insulation conditions, the mathematical formulas governing the steady-state stress distribution within the cable insulation are of the same form for dc and for ac, resulting in comparable relative values; however, should the cable insulation contain defects in which either the conductivity or the dielectric constant assume values significantly different from those in the bulk of the insulation [Editor: That would be all aged cable!], the electric stress distribution obtained with direct voltage will no longer correspond to that obtained with alternating voltage. … Furthermore, the failure mechanisms triggered by insulation defects vary from one type of defect to another. These failure mechanisms respond differently to the type of test voltage utilized. For instance, if the defect is a void where the mechanism of failure under service ac conditions is most likely to be triggered by partial discharge, application of direct voltage would not produce the high partial discharge repetition rate that exists with alternating voltage. Under these conditions, dc testing would not be useful. However, if the defect triggers failure by a thermal mechanism, dc testing may prove to be effective. For example, dc can detect the presence of contaminants along a creepage interface.

In the case of joints and accessories, their dielectric properties may differ from that of the cable with regard to conductivity. This may result in a dc stress distribution at the interfaces between the cable and the accessory that is very different from the stress under ac voltage. A careful examination of the system is necessary prior to a dc test in order to avoid difficulties.

Testing of cables that have been service aged in a wet environment (specifically, XLPE) with dc at the currently recommended dc voltage levels (see IEEE P400.1) may cause the cables to fail after they are returned to service (see Fisher, et al. [B23], and Steennis, et al. [B48]). The failures would not have occurred at that point in time if the cables had remained in service and not been tested with dc (see Eager, et al. [B21], and Srinivas, et al. [B47]). Furthermore, from the work of Bach, et al. [B7], we know that even massive insulation defects in extruded dielectric insulation cannot be detected with dc at the recommended voltage levels.”

In short, …

1.    DC testing does not measure the same defects to which the subject cable is exposed in its AC environment.

2.    There is little or no relationship between DC test results and likely AC performance.

3.    DC testing damages the aged cable it seeks to diagnose.

LIPA Validation

If the purveyors of the LIPA test wish to validate their test they simply need to run an experiment with a suitable control. To wit, divide a population of, say 100, homogenously aged cables into a control group of 50 and a test group of 50. Monitor the performance of the control group for future failure history. Submit the 50 cables in the test group to LIPA, and then monitor that group for future failure history. If the purveyor’s claims are accurate, there will not be a significantly higher failure rate in the test group compared to the control group and the failure rate in the subgroup of the test group that tested “bad” should be significantly higher than those of the test subgroup that did not test bad. Since PowerTech is a subsidiary of a utility with a sizable population of appropriately aged cables, it should be a simple matter to arrange such a test. This frog is unaware of any such test. Without the simple application of the scientific method the claims of efficacy cannot be confirmed by this, or any other frog.

Rejuvenation Methods Tested

Novinium can and does utilize both method A and method B. Method A is properly called unsustained pressure rejuvenation or UPR. Novinium has made improvements to the UPR method. The improved UPR method is called iUPR. Method B is sustained pressure rejuvenation or SPR. SPR outperforms UPR and iUPR by any measure of post-injection reliability.

Representative or Not?

Not – for two reasons. First, as mentioned above, the LIPA test should not be used to judge AC reliability. Second, even if LIPA were a valid test, 13 samples for UPR and 4 samples of SPR are not statistically significant.

Novinium is the only rejuvenation vendor in the world that performed a full third-party, side-by-side controlled experiment of rejuvenation technology. The work was executed by NEETRAC and the results are extraordinary. As soon as those results become public you can read about them here. In the mean time, actual post-injection performance of better than 99.6% on millions of feet of cable can be viewed at …

www.novinium.com/Lessons.aspx

Always skeptical of claims without data,

T. B. Frog

Better Than New

Dear Learned Leaper,

Why would I use rejuvenation, when I can have new cable?

Cable Guy

Dear Cable Guy-

I suspect, Cable Guy, that you’re not a circuit owner. Do you work for one of the cable manufacturers? If you were a circuit owner, you would know that money does not grow on trees and rejuvenation is almost always considerably less capital intensive than wholesale replacement. The question would have had more merit had it been asked two decades ago when the first generation of rejuvenation technology was becoming commercially important. The anticipated life of the first generation of fluid in non-demanding applications was and remains about two decades. The generally anticipated life of post 1990-vintage cables is about four decades. The 2X difference in anticipated life complicated the economic analysis of the treat or replace question. Advanced technology from Novinium can provide the same four-decades of service life, so that issue is a relic of the 20^th Century.

How about post-injection reliability? In the January 31, 2012 issue of the Las Vegas Regional Journal, it was reported that NV Energy experiences about a 0.6% failure rate when it replaces cable. NV Energy reports that the older injection approach has about the same failure rate over a 12-year period. Utilizing Novinium’s state-of-the-art technology and the outstanding craftsmanship of our service delivery experts, our overall failure rate is less than 0.4%. That’s about 33% better than the failure rate of new cable. Novinium rejuvenation technology is better than new! But, here’s the really cool part, Novinium technology and delivery methodology continues to improve! In the graph nearby I am pointing at the beta value of our Crow-AMSAA analysis of all of the faults we have ever experienced treating millions of feet of cable on three continents. The value is 0.56. A value less than one indicates that the failure rate is decreasing – a one would mean that it is staying the same, and a value greater than one would indicate deteriorating reliability. To learn more about Crow-AMSAA, check out my August 11, 2011 post, “Crow.”

Novinium announced the passing of the “Better than new” milestone today. Click here to read the press release. We periodically post a transparent summary of our failure history at novinium.com/Lessons.aspx.

Better next year,

Thermo B. Frog

The Color of Capital

Dear Gregarious Green One,

My firm uses Ultrinium™ and Sustained Pressure Rejuvenation to treat cables after they fail. The ability to capitalize single section injection with Novinium technology means we can earn a regulated rate of return on the capital thus expended. I read your four-part blog, “The Color on Money” and was wondering if you could do a similar analysis to help us quantify the benefit of our approach.

Considering Capital in Colorado

Dear CCC-

I am pleased that you appreciated my “Color of Money” posts. Click on I, II, III, and IV to review that work. Many of the concepts in the “Color of Money” apply to the “Color of Capital.” In fact, Parts II and III are prerequisites if you need a primer on depreciation and the time value of money respectively.

The ability to capitalize single sections of injected cable is available only from Novinium. In FERCs (Federal Energy Regulatory Commission) Letter order dated January 18, 2000, John Delaware, the Chief Accountant, wrote to the petitioner, Georgia Power:

“You indicate that CableCURE is used to rehabilitate entire segments of your underground distribution system (e.g. entire residential subdivisions as opposed to individual runs of cable between two terminal points).”

The only way you can capitalize CableCURE is if the entire subdivision is rejuvenated. The letter order is attached to this post for the interested reader. Novinium’s technology has no such limitation. The Letter Order promulgated by FERC’s Chief Accountant on September 4, 2008 and associated submittal information removes that limitation and can be accessed by clicking here. All of the above discussion is also true for RUS-funded circuit owners. Click here is view the RUS order of April 3, 2009.

That takes care of the regulators; now the analysis. We will compare two cases. All of the inputs are shown on the worksheet nearby. Parenthetical references to the worksheet cell designations appear in the following text.

Case 1

The cable fails, is repaired and put back in service. In our model the user can indicate how many faults are tolerated before the cable is replaced, together with an estimate of the time between faults. For this example, we assume the cable will fault twice over a two year period before it is replaced. The capital cost to replace is a modest $33.00/ft (Cell B7) and the O&M cost of a fault is $13.72/ft (Cell D13) in today’s dollars. That’s $4,500 (Cell B11 + Cell B12) divided by as assumed segment length of 328 ft (Cell B13).

Case 2

The cable fails, is repaired and injected in a single integrated operation. In our model the bundled unit capital is $20.06/ft (Cell D23). The model user can change any of the costs inputs and an assumption of the post-treatment reliability. For this example, the post-treatment failure rate is assumed to be 2% (Cell B26), which is about twice Novinium’s actual post-failure experience of about 1%.  To put this 1% failure rate in perspective consider that it is three-times higher than Novinium’s non-post-failure experience of about 0.34%. This higher-than-typical post-treatment failure rate is inherent in post-failure treatment. The post-injection fault is assumed to occur two years (Cell B27) after injection. Again the model user can adjust any of these assumptions.

Other Assumptions

Warranty remittances of $10/ft (Cell B23) are negative capital expenditures, that is, the remittances are subtracted from the subsequent replacement capital. Upon post-injection failure, the book value is written off, terminating the ratemaking-allowed return and providing a lump sum tax benefit of the book value. Cash flows are calculated for two rehabilitation cycles, up to 100 years. This approach allows residual values to be properly ignored as de minimis. Finally, replacement is assumed to have a zero-percent failure rate. At least one major investor owned utility has reported that new installations suffer a 0.6% “infant mortality” failure rate, and hence this assumption results in a slight understatement of the incremental value of Novinium^® post-failure rejuvenation.

Bottom Line

The cumulative net present values (NPVs) for the two cases are plotted nearby. Since the revenue or sale of electricity is the same in all cases, those revenues are ignored and only capital and O&M costs are depicted. This cost-only analysis is why all of the NPV values are negative. Nonetheless, the higher the cumulative NPV value is on the graph, the more advantageous to the circuit owner.

The blue line is for Case 1, and in the short run it is the superior choice. The problem is that once a cable begins to fail, it will re-fail. Sooner or later the ratepayers will be very upset with deteriorating reliability. Capital inefficient replacement is executed after the second fault (Cell B14) and the NPV plummets.

The orange line is for Case 2, and it represents an investment in reliability. The initial cost is about twice as great, but because the investment is capital, the circuit owner begins to earn a regulated rate of return. In the end, the incremental NPV advantage of Novinium post-failure rejuvenation is $18.42/ft. If your replacement cost is higher, say $44/ft, the difference becomes $21.15/ft. If in Case 1, the cable is allowed to fault a total of three times, the difference rises to $24.56/ft. Even if the cable is replaced after a single fault, the best alternative to rejuvenation, rejuvenation still enjoys an $11.45/ft advantage.

If you would like to run this model on your specific circumstances and execute “what if” scenarios, contact us at novinium.com/Contac.aspx.

Always conserving capital,

T. B. Frog

70-20120322_FERC_Letter_of_Approval.pdf (78.87 kb)

Euro-Rejuvenation

Dear Thermo,

I heard that besides the old rejuvenation technology offered by UTILX and Novinium’s improved technologies, that there is a third competitor in Europe.  Pray tell?

Hedging my bets

Dear Hedge-

There is only one firm in the world that can provide advanced Novinium technology. Today there are a total of twelve U.S. patents and their foreign equivalents. An up-to-date list of those patents is available at …

novinium.com/patents.aspx

If you want the safest and most reliable technology in the world, Novinium and our partners are the only source. Our friends down the road at UTILX Corporation offer technology invented by Novinium founders about two decades ago. Our founders are proud of their achievements, and this frog has written extensively that the performance of that old approach is quite good for non-demanding applications. Check with your risk management folks before you use that approach, however, because Novinium technology is much safer. Heaven forbid that you find yourself justifying your choice of a less safe choice to a jury. For a thorough discussion of the risks with all of the commercially significant injection approaches, check out my June 9^th, 2010 post, “Biggest Risk is Electrical.” Within that post is a link to a comprehensive risk analysis titled …

Rejuvenation Hazard Analysis 

There is a firm in Germany that offers silicone injection of power cables.  Their website is at …

www.kabelsanierung.de

Next, click on “Kabelsanierung,” which is German for cable rehabilitation. The firm is run by Professor Rudolf Wimmershoff formally at the Technical University of Regensburg. To this frog’s knowledge, Professor Wimmershoff’s rejuvenation approach has not been used too far from Bavaria. This frog cannot recommend the good Professor’s approach. He utilizes a common siloxane oligomer, which is generally used to waterproof masonry and such. The oligomer cross-links to a thick fluid resin after injection. The problem with this chemistry is that cross-linked polymers in the strand interstices can do nothing to improve the insulation’s dielectric properties, because they are way too big to diffuse into the insulation. To this frog’s knowledge there have never been any papers written to describe the post-injection performance of the good Professor’s approach. The firm’s primary businesses are transformer diagnostics and cable diagnostics.

Auf Widersehen,

Fehischlag Frog

P1816

Dear Thermo,

What is this swanky “reliability” event that Novinium is sponsoring on the Seattle waterfront in conjunction with the ICC meeting on March 26, 2012?

News in Jersey

Dear Jersey-

First I wish to object to prejudiced policy promulgated by local health authorities. Amphibians are prohibited from attending the March 26^th event to which you refer. Not that I would have any interest in the menu, I won’t eat anything unless it is still moving. The human proclivity to eat long-dead stuff is abhorrent. Forget the food; denying me access to the content is what frustrates my flippers.

IEEE P1816™ is a soon-to-be-approved, “Guide for Preparation Techniques of Extruded Dielectric, Shielded Cable Rated 2.5 kV through 46 kV and the Installation of Mating Accessories.” P1816 starts where most accessory installation instructions end. It defines the best practices for accessory installation that will lead to the highest level of reliability. The P1816 Guide was assembled by circuit owners, component manufacturers, and reliability masters like my Novinium colleagues. On March 26^th, humans who have a stake in reliability will gather to kick-off a multi-part series of webinars that will delve into the details of high-reliability craftsmanship.

Regular attendees of the Insulated Conductors Committee (ICC) will recognize the speaker’s names as authorities on the subject of reliability. Vern Buckholz, an expert on neutral corrosion, Glenn Luzzi of Richards Manufacturing, and expert on cable accessories of all types, Harry Orton an expert on sources of reliability problems, Mike Smalley of WE Energies, a P1816 Co-chair, and Bill Taylor of 3M, an expert on splices and terminations, are just some of the proficient people who will be introducing the topic and setting the stage for a year of informative webinars designed specifically to spread the gospel of reliable craftsmanship. The webinars will be designed for the craft-folk that largely determine the post installation reliability of underground cable components. Management and engineers should plan on attending too, because there will be revelations for all.

Select attendees will also be given access to Novinium’s state-of-the-art eLearning “Cable Prep Course” based upon P1816 at knovinium.com and a companion field guide. If you have not been invited to this invitation-only event, contact your Novinium sales professional at novinium.com/Contact.aspx. To see the agenda click here.

Unable to attend myself, but there in spirit,

T. B. Frog

The Color of Money – Part IV

In my post of February 27^th, The Color of Money – Part I, I gave the big picture answer to Cap’s query. In February 28^th’s follow-up post we delved into the details of depreciation. On my Leap Day post we deliberated discounting. Today, in the fourth and last post of the series, we will tie up loose ends and cover the rest of the assumptions.

Rejuvenation Technology Inputs

In cells B12, B13 and B14, the name for “Product X”, the fully absorbed cost for product X, and the warranty length are entered respectively. Cells B16, B17 and B18, hold the same values for “Product Y.” Cell B20 is the ratio of the warranty length of Product Y divided by the warranty length of Product X.  The accounting lives are assumed to be the respective warranty lives.  The actual life multiplier in cell B21 is the ratio of the actual life of Product Y divided by the actual life of Product X. The warranty life is an approximate indicator of the actual life, as the technology suppliers use some combination of experience, accelerated life experiments, and accelerated life simulations to arrive at reliable life expectations.

For individual large and stable firms, such as most utilities, the spread or difference between the discount factor in cell B3 and the inflation rate in cell B6 is quite constant. If inflation increases, discount factors increase too. The 5.9% spread in the example is typical for the power distribution industry in North America.

Accounting Treatment of Warranty Remittance 

GAAP would suggest that warranty remittances are handled as negative capital expenditures. That is, the cost of replacement is reduced by the amount of the warranty remittance. Any remaining undepreciated value associated with rejuvenation is written off in the year of the failure on both the tax books and the rate-making books. Individual circuit owners may treat these warranty refunds differently. Write to me to tell me how your firm accounts for these warranty payments.  I’ll enhance the model to accommodate your method.

Residual Value

For any net present value analysis there has to be an assumption regarding the handling of residual values at the end of the analysis period. Where two rejuvenation technologies with different actual lives are compared, the technology with the longer life will have a greater residual value than the product with lesser life. For the purposes of this analysis a single replacement cycle is executed after the rejuvenation cycle has completed and future value is calculated to a one century horizon. Cash flows after 100 years are ignored. This assumption favors the technology with the shorter life, since the product with the longer life would have the greater residual value.

Bottom Line

This rigorous analysis confirms and quantifies what should be self evident. The longer the life – the greater the value.

Greener is better,

Thermonuclear Frog