Light Weight & Climbable: Two Idaho Utilities Use Cedar Poles

Using 50 ft. full-length penta treated cedar poles, this Fall River Electric substation between Ashton and Yellowstone Park was bult in 1966.

Fall River Electric has used Western Red Cedar poles for many years with 99% of their system built on cedar.  Climbability and light weight are the principal features which Fall River Electric finds important in the use of cedar.  Laminated wood poles are sometimes used for corners to minimize guying. 

There are about 20,000 cedar poles in their system.  Some 120 miles of transmission lines carry either 115kV or 46kV lines.  The utility also has 2,000 miles of 12.5kV distribution lines.  Fall River’s oldest cedar poles still in service were installed in 1940.

This line, built in 1999 with 75 ft. cedar poles, delivers power to customers near Yellowstone National Park.

Single family homes account for 53% of Fall River’s power consumption. Commercial is 13%, industrial is 28%. and 6% is miscellaneous.  Most industrial use is irrigation pump power.  Industrial uses include golf course irrigation, and power for ski areas.

Fall River’s peak loads used to occur for irrigation.  Today, peak loads come from residential use that has seen a steady 6% yearly growth.

Much of the power used in Fall River’s system comes from Bonneville Power Authority with 10% from Fall River’s Island Park Hydro and Buffalo River Hydro.  Power sources are 85% hydro electric generation and 15% nuclear generation.

Fall River Electric is so close to Yellowstone Park and participate in sponsoring an annual dog sled race to Yellowstone Park each year.  Participants have a choice of five different races, including 100, 80, 60, 40 and 20 mile races plus a Junior race and a snowshoe race.  There was an ample amount of snow for the race this year.

A 600 foot crossing of the Snake River, this line is scheduled to be rebuilt this year with cedar poles.

Continuing growth has necessitated additional lines to serve new developments.  The utility, which has consistently used cedar for years, has 386 miles of distribution lines, 70% of which are overhead supported by about 14,000 cedar poles.  Approximately 37 miles of transmission lines also use cedar poles.

New lines continue to be built and extended in various areas of the city, plus a number were re-conductored and upgraded from 4.6kV to 12.5kV in recent years. 

Idaho Falls Power consumption is 42% residential, 38% commercial, 14% industrial and 6% other.  Annual utility energy use is 716,000 megawatt hours

Most of the power supplied to Idaho Falls comes from Bonneville Power Authority.  However, Idaho Falls has several generating stations of their own with another project under study.  The Bulb Turbine station generates 143,000 megawatt hours with three low-impact bulb turbines.  The single turbine Gem State station generates 122,000 megawatts.

This line was built along the Snake River uses 85-ft. H-1 cedar poles to raise the height of the wires so the office building to the west would have an unobstructed view.

Idaho Falls Power offers several pro-grams to help the community conserve energy.  Through their Residential Weatherization program, the utility conducts free energy audits for making homes more energy efficient.  Commercial customers can conserve power and reduce costs by having their lighting, HVAC systems and controls evaluated through the Commercial Energy Efficiency program.   Additionally, their Appliance Efficiency Program helps replace inefficient equipment such as heat pumps, water heaters, freezers and refrigerators. 

Customers are kept informed on utility issues including electric safety and energy efficiency through their website, news-letters, brochures, newspaper, radio and television.  Periodically customers are surveyed to find out what can be done better, and what other services they would like to see offered.    

Idaho Falls has a long working relationship with Bonneville Power that includes participating the last six years in a wholesale power agreement with BPA known as Slice -- a Slice of the System.  Under the Slice agreement, Idaho Falls Power receives a percentage of the generation from the Federal Columbia River Power System.    After evaluating the results, Idaho Falls believes this program has been a successful one for the utility.

Additionally, Idaho Falls Power is one of the original founders of Idaho Energy Authority (IDEA).  Through IDEA, Idaho Falls Power and 13 other members have contracted for a 30-year network transmission service with the BPA. 

The Hardening of Utility Lines -- Implications for Utility Poles Design and Use - Part 1

A reprint of the first portion of the North American Wood Pole Council Technical Bulletin VII, this publication was prepared by Martin Rollins, PE.  For the entire technical bulletin, and more information about wood poles the reader can access www.woodpoles.org.  

ABSTRACT

The hurricanes of 2005 caused unprecedented damage to critical infrastructure on the Gulf Coast, including electric utility distribution and transmission systems.  Significant damage has also been caused recently by ice storms and extreme wind events in other parts of the country.  The Public Service Commissions of several states questioned the performance of the power delivery systems in these storms, and initiated work to investigate the potential need and effectiveness of “hardening” the system to improve performance in future storms.  This paper provides a qualitative evaluation of the expected and actual response of the electrical distribution system in these storms.  In general, the system performed as expected and potential actions to “harden” the system could be very expensive and the potential benefits are unquantifiable.

INTRODUCTION

The devastation of Hurricane Katrina in 2005 made all prior storms look tame in comparison.  Hurricane Katrina caused over 80 billion dollars in damage and easily became the most expensive natural disaster in history.  The 2005 hurricane season was possibly the most active Atlantic hurricane season on record, with a total of 28 storms, 15 hurricanes and 7 major hurricanes.  Four of the major storms, Dennis, Katrina, Rita and Wilma, struck the Gulf Coast with total damages exceeding 120 billion dollars and more than 2,200 fatalities.

In December of 2006, the Pacific Northwest experienced an extreme wind event that caused more than 1.5 million customers to lose power.  Also in December of 2006, a severe winter storm resulted in heavy icing in portions of the Midwest.  More than 500,000 public utility customers lost power in Missouri and Illinois alone.

These extreme weather events have caused the public to question whether more can be done to prevent these outages or reduce time to restore power, and this has resulted in the Public Service Commissions (PSCs) of several states starting formal inquiries into the need to harden the systems.

DISCUSSION

The investigations by the various state PSCs have not focused only on hardening the system as a means to improve extreme weather performance.  Vegetation management, line inspection and maintenance, line relocation, and undergrounding are among the other opportunities identified for improved storm performance.

The basis for reaching decisions concerning system improvement must be founded in an accurate forensic analysis of actual failure mechanisms.  The various states have found that this information is very difficult to determine with a reasonable degree of certainty.  In some cases, it has been possible to develop qualitative data to confirm or deny some early hypotheses.  In the Gulf Coast region, initially the performance of wood poles was questioned.  Both the States of Texas and Florida considered eliminating the use of wood transmission poles.

This bulletin will be continued in the next issue of Cedar Pole News.