A Survey of the Research, Development and Demonstration (RD&D) Activities in the utility vegetation management industry was conducted in February 2009. The membership of the Utility Arborist Association (UAA) was invited to respond to a variety of questions related to their level of involvement in, their interest in and the usefulness of the current body of utility vegetation management (UVM) RD&D work. The survey also asked respondents to identify unaddressed needs for additional RD&D.

While the need for more RD&D was identified, it can be a hard sell in today's difficult economic environment. That said, utilities are recognizing they cannot “save” their way to prosperity by focusing exclusively on cost-cutting measures. RD&D represents an investment in the industry's future success.

RESEARCH, DEVELOPMENT AND DEMONSTRATION

The U.S. National Science Foundation (NSF) conducts an annual survey of industrial R&D. The scope of that survey includes work “undertaken on a systematic basis to increase the stock of knowledge and the use of this stock of knowledge to devise new applications.” The NSF survey subdivides R&D into specific categories:

  • Basic research

    Gain comprehensive knowledge or understanding of the subject under study without specific applications in mind, using formal protocols.

  • Applied research

    Gain knowledge or understanding to meet a specific, recognized need, using quantitative and qualitative methods.

  • Development

    Apply knowledge and understanding gained from research to the development of useful materials, methods and processes.

INVESTMENT IN RD&D

Although not included in the NSF definitions of R&D, the following two categories are useful to the industry:

  • Informal studies

    Gain understanding of a specific need using less-rigorous qualitative methods.

  • Demonstration

    Apply lessons from R&D under operational conditions to demonstrate usefulness and gain acceptance.

EPRI (Palo Alto, California) estimates that the total investment in T&D infrastructure in the U.S. is more than $350 billion. Transmission accounts for approximately 30% (less than $100 billion) of this investment. The remaining portion, the distribution system (approximately $250 billion), includes both overhead and underground lines.

Excluding underground lines, which typically are not included in UVM programs, these rough calculations suggest that the industry's capital investment in overhead T&D lines is between $200 billion and $250 billion. The current estimate of the annual cost of vegetation management activities is $2.5 billion. Put another way, the annual cost of maintaining vegetation is about 1% of the capital investment.

That's the cost of maintenance, but what about the UVM industry's RD&D spending?

COMMITMENT TO RD&D

As previously noted, the NSF collects financial data related to R&D activities from companies performing R&D in the U.S. The most useful metric in comparing RD&D spending across industries is an expression of R&D as a percentage of annual sales. The average R&D outlay across all industries peaked at 4.2% in 2001. Since then, it has been in decline and has varied to as low as 3.5%.

In contrast, R&D spent by the utility industry is less than 1% per year. The consulting firm Accenture (Hamilton, Bermuda) has reported that while utilities represent 5.23% of U.S. capital spending, the industry only represents 0.067% of U.S. R&D spending (see “How to Achieve High Performance,” Public Utilities Fortnightly, September 2007).

Using these indices as a guidepost, it would seem reasonable to expect that the investment in RD&D within the UVM industry should be on the order of 0.50% to 0.75% of the annual cost of vegetation maintenance. This would mean an individual utility might spend between $5,000 and $7,500 per year in RD&D for every $1 million of a vegetation management budget. At a composite level, these ratios would justify an industrywide investment in UVM-related RD&D on the order of $15 million each year.

MAIN RD&D DRIVERS

In the recent UAA survey, members were asked, “Does your company conduct UVM RD&D in its many forms, either in-house or through the use of third-party consultants?” A full 67% of respondents confirmed their organization's involvement in RD&D. Perhaps more revealing are the reasons given by the 30% of respondents who indicated their organization had no involvement in RD&D:

  • No interest in RD&D
  • Unlikely to yield benefits
  • Work being done by others
  • No need identified
  • No time for RD&D
  • No budget for RD&D.

Clearly, the dominant theme for lack of participation comes down to resources — the lack of time and money — rather than interest in RD&D in and of itself.

There are several reasons for establishing an investment in RD&D. First, and most obvious, is the opportunity to identify and capture benefits in improvements to processes and methods. The power-of-large-numbers effect creates a powerful argument for an investment in RD&D. Small incremental changes can result in significant benefits when carried across a large utility's vegetation maintenance budget, even more so when the industry's annual cost of UVM is at $2.5 billion per year.

SIGNIFICANT PAST EFFORTS

Second, RD&D investments also can be justified on an avoided-cost basis when the direct, and potentially indirect, cost of tree-caused interruptions and other adverse events such as public safety and wildfires are considered, not to mention the possibility of adverse regulatory attention.

Third, there is the matter of management intent. RD&D has the potential to support a utility's effort to achieve a stated goal of top quartile or decile performance, or even to strive for best-in-class performance. RD&D can be one of the cornerstones in achieving industry thought-leader standing.

The UVM industry has a history of involvement in RD&D. Respondents to the recent survey were asked to identify the RD&D project that has had the greatest impact on the industry. Not surprisingly, efforts related to the use of herbicides in selective vegetation management ranked highly. This is likely due to at least two factors.

First, the development of selective herbicide formulations and applications dramatically altered the manner in which vegetation maintenance is conducted, from manual and mechanical clearing to truly managing vegetative cover types in favor of the establishment of stable plant communities.

Second, the manner in which new ideas are introduced intuitively lends itself to the establishment of test plots. It was natural for the industry to be involved in RD&D for herbicide use and with tree growth regulators (TGRs), as well.

RD&D in its various forms also has changed the way in which utilities approach line clearance. Work on tree response to pruning, decay and structural integrity has increased utility arborists' understanding of how risk is created and mitigated. The frame of reference of utility arborists has moved from thinking in terms of simple control to a realization that they are managing biological systems and organisms that respond to management.

Contemporary line-clearance pruning specifications incorporate proper arboricultural techniques and practices that are rooted in sound science supported by RD&D. These practices recognize that when a tree is pruned, there will be a wound response and re-growth response. In this way, utilities are able to reduce the cost of future maintenance and the risk of tree and branch failure, thus reducing subsequent outages.

AGENDA FOR THE FUTURE

RD&D work characterizing tree-initiated electrical faults has led to a new understanding of risk to system reliability and safety. The impact of this work on the UVM industry is evident in distribution-system vegetation management plans that recognize that tree-related risks vary within a circuit and are much lower on single-phase lateral lines.

It is also worth noting that UVM RD&D is not exclusively focused on understanding tree-conductor conflicts in their various forms. A good example of this is an oft-cited study of the economic impacts of deferring vegetation maintenance (see “The Economic Impacts of Deferring Electric Utility Tree Maintenance,” Journal of Arboriculture, May 1997).

The need for RD&D has not diminished. In fact, an argument can be made that the future need will increase.

Consider the nature of the problem. The basic maintenance requirement relative to vegetation of all in-service overhead T&D infrastructure is simply to preserve insulating characteristics. The T&D plant is extensive and not likely to change in this regard anytime soon, and the manner in which vegetation presents risk has not changed appreciably.

This suggests that the future of UVM will more likely be one of incremental rather than step change. In this environment, RD&D efforts will be a valuable tool for identifying opportunities for incremental improvement. As pointed out previously, even small gains result in substantial benefit when the magnitude of vegetation maintenance expenditures is considered.

Survey respondents ranked “reliability” and its close-cousin “risk identification and mitigation” as the most important areas of focus for future research.

FUND ALLOCATION

Workforce-related issues of safety, training and development also were high on the RD&D agenda. Other broad areas of interest such as technology, environmental considerations and the impact of regulations reflect the utility industry's place in contemporary society. Interestingly, while still in the top 10, herbicide-related RD&D is no longer the dominant area of interest it has been in the past.

Any discussion of the future portfolio of RD&D begs the question as to who is going to fund and complete the work. The ratios presented earlier can be applied to either cost or revenue, but not to both. The vast majority of utility vegetation maintenance budgets are allocated to contract service providers. Both utility owners and service providers have a legitimate business interest in RD&D. It should be noted that involvement does not necessarily mean funding sources.

Applying a conservative ratio of the overall utility industry's commitment to R&D to the UVM industry suggests that an investment of approximately $15 million per year should be allocated to RD&D. There is no direct means of determining the UVM industry's actual commitment. Clearly, some well-publicized projects are funded each year by individual utilities and various consortia. However, they rarely would account for even 10% of the suggested level of commitment.

Another means of assessing the amount spent is to express it in terms of a hypothetical staff of approximately 200 full-time equivalents committed to RD&D. This represents 10% of the UAA membership. It's unlikely that one in 10 UAA members works full time on RD&D, nor do all UAA members spend 10% of their time on RD&D.

The Tree Research and Education Endowment (TREE) Fund has funded approximately $400,000 in UVM RD&D and an additional $370,000 in projects with some relevance to the UVM industry over the past 10 years. This would equate to an annual commitment of $77,000. EPRI has spent about $100,000 per year on UVM-related research since inception of this program area in 1995.

UVM-related RD&D is significantly underfunded. This gap will be closed when leadership within the industry recognizes the untapped potential value and are willing to make an investment. Industry thought leaders from within the ranks of utilities and their service providers should be congratulated for their vision. Building from this base, work must begin to raise the level of awareness and sense of opportunity with senior utility managers and, potentially, regulators.

RD&D projects represent an opportunity to create value and drive incremental improvement in vegetation management practices, system reliability and safety, with the added potential of lowering costs. An increase in the industry's commitment to UVM RD&D represents a strategic investment.


EPRI RESEARCHES AIR GAP SPARK-OVER BETWEEN CONDUCTORS AND TREES

John W. Goodfellow (jwgoodfellow@msn.com) is a principal consultant for BioCompliance Consulting Inc. and a vegetation management researcher with more than 25 years experience in the electric utility industry. He has held positions of responsibility for vegetation management, engineering and field services at three large investor-owned electric and gas utilities. He also has been responsible for managing T&D services for a major contracting organization. He has bachelor's degrees in forestry and natural resources management from Syracuse University and the SUNY College of Environmental Science and Forestry.

The wide-scale Aug. 14, 2003, U.S.-Canada blackout was initiated by tree contacts on the bulk power system. As a result FERC, and subsequently NERC, have been keenly focused on tree-related risks to the high-voltage transmission grid. A critical, preventable risk to reliability of the transmission system involves conductor contact with trees within the maintained right-of way corridor. Trees growing into contact with conductors and/or conductors sagging into contact with trees during the summer growing season create this risk.

NERC Standard FAC-003 “Reliability Standard Vegetation Management Program” establishes minimum tree-conductor clearances for transmission lines. These distances are based on the dielectric properties of the air gap, and the position of an energized conductor and low impedance electrode. Recent research involving high-voltage tree contacts resulted in the development of an electrical circuit model for living trees. This work found that the impedance of the fault pathway provided by a tree initially is quite high (300 kÙ to 800 kÙ).

In May 2009, 50 hybrid poplar test trees were planted at EPRI's Lenox High Voltage Test Lab. These trees, as well as some native stems already occurring within and adjacent to one of the transmission test line corridors, will be used in an investigation of the influence of the high impedance of the fault pathway through trees on air gap spark-over distances to conductors energized at transmission voltages.

High-voltage testing of air gap spark-over distances to naturally occurring edge trees adjacent to the cleared corridor are planned for in 2010. The newly planted hybrid poplar and naturally occurring test trees within the test corridor should achieve suitable size in their third growing season (2011) for additional high-voltage air gap spark-over tests. EPRI is seeking funding partners for this important project. For more information, contact John Goodrich-Mahoney at 202-293-7516, or JMAHONEY@epri.com.