Tactical eagle eyes look back at an employee gazing out the window of Alaska Electric Light & Power Company (Juneau, Alaska, U.S.). Scanning the environment for its next bite of food. Unaware of the shadow its majestic silhouette casts down on Lemon Creek Substation and the electrical hazards within. Every year one eagle takes its last bite when it contacts energized electrical equipment. The employee counts 1, 2, 3…12 bald eagles today. However, today is different than the prior two decades thanks to wildlife protection improvements. AEL&P has implemented a new green approach. And the fear once associated with the consequences of eagles flying above the substation has been transformed. Today, the bald eagles seen through the office window are being admired for their resemblance to the beautiful snowcapped mountain backdrop found in Juneau, Alaska.
Wildlife Matters
Juneau is in the Tongass National Rainforest and 93 miles from Glacier Bay National Park. No wonder its natural beauty is stunning. It is also the perfect place to find an abundance of wildlife, which increases the challenge for AEL&P to provide reliable and responsible electric service. A challenge shared with all electric utilities. Nationally, about 20-percent of all power outages are attributed to wildlife (https://www.nytimes.com/2013/09/01/opinion/sunday/squirrel-power.html). It is a little higher in Juneau, closer to 30-percent. Wildlife is a broad reference to many types of animals and birds; however, the bald eagle is AEL&P’s big concern. At least one eagle-related outage occurs every year at the Lemon Creek Substation. This annual event interrupts power to 58-percent of AEL&P’s 17,023 customers and accounts for about 20-percent of customer-outage hours each year (SAIDI: 21 minutes).
Wildlife safety matters to electric utilities. Outage response, damaged equipment, interruption of service, wildlife fatalities, and potential for regulatory fines all add up and are all detrimental to the mission of utilities. AEL&P has been updating and implementing wildlife protection plans for over 20 years and has made great strides in improvements. Countless pieces of wildlife protection products have been used system wide to improve existing infrastructure. New infrastructure takes wildlife into consideration in the design phase prior to construction. The Avian Protection Plan Guidelines by the Avian Powerline Interaction Committee (APLIC) and U.S. Fish and Wildlife Services (USFWS) serves as a resourceful basis for utility standards and planning. Wildlife protection has social, environmental, and economic benefits to utilities that support being able to provide safe, reliable, low-cost, and responsible electric service. It pays to protect.
Alaska Sized Challenge
Substations are more susceptive to wildlife interactions due to the increased amount of electrical equipment. The Lemon Creek Substation is one of AEL&P’s largest facilities integrating 69 kV transmission lines, 12.5 kV distribution feeders, and a large back-up generator power plant. There are 10 back-up generators, 5 power transformers, voltage regulators, interrupting devices, overhead buss, support structures, instrument transformers, and switches that all are potential points of interaction with birds. Across the fence from the substation is Juneau’s local landfill, which creates a vast food attractant for birds. Droves of birds, reminiscent of Alfred Hitchcock’s movie “The Birds”, can be found here including bald eagles.
Wildlife protection products typically target distribution voltage class equipment because this is where more interactions occur with commonly found birds like crows. Most “off of the shelf” type products are designed to conveniently fit a range of commonly sized equipment like insulator bushings. A quick scan across the Lemon Creek Substation would reveal many of these products installed. Although they are having a positive impact, some birds still manage to come into contact with energized equipment. Especially at sites with high volumes of birds like the Lemon Creek Substation.
Birds are very good at finding vulnerabilities in the best of wildlife protection plans. This is because generic products can be loose fitting, leaving gaps into which birds can poke their beaks or other body parts. It is also hard to find products for less common equipment like air break disconnect switches or support structures. The 69 kV transmission line enters and exits Lemon Creek Substation through two Turner Electric 3-way ganged operated switches mounted on steel poles. Bald eagles are big birds with wing spans up to 60-inches. Unlike gulls or crows, the eagle’s wingspan can make it susceptible to hazardous situations from these high voltage pieces of equipment. Transmission line outages are almost certain to be fatal to the bird and have a greater impact on system reliability.
The New Green Approach
Wildlife mitigation often is a reactive approach to incidences, especially on existing electrical equipment. However, utility responses to wildlife incidences are not limited to “off the shelf” options. As Aaron Watson said at the Grizzly Rose concert in Denver this spring, “…it’s time to turn the volume up a notch; no, let’s turn it up eleven notches!” He turned the intensity way up, and AEL&P has followed suit with our wildlife protection by partnering with Greenjacket Incorporated and engineering custom site-specific solutions.
The process started with an initial review of Lemon Creek Substation drawings to identify perch locations and hazardous contact points for birds. Combining this information with an understanding of motivating attractants, behaviors, and physiology helped build a preliminary project scope. Lemon Creek Substation’s general configuration was built before AutoCAD’s first release in December 1982. A site survey was needed to collect photogrammetric data for building a three-dimensional computer aided model. Engineers then use the model to design custom-fit polymer molded pieces to cover every contact point identified. It might not be a surprise that the number of pieces added up quickly along with the initial budget proposal.
Correlating the preliminary design with AEL&P’s incident tracking records helped refine the scope and budget to about $143,900 for manufacturing. A future planned solution was also engineered for another substation named West Juneau. It is a more typical substation layout, since there is no power generation plant located at this site. A 69 kV transmission line is connected through an interrupting device to a 25 MVA GE power transformer. The voltage is stepped down to 12.5 kV to serve four distribution feeders. Project costs are expected to be about $65,000. If the Lemon Creek Substation project, the highest priority, is successful, then we anticipate implementing future sites like West Juneau Substation.
This really is “eleven notches” more than past practices, in a good way. Utilities will successfully capitalize on demonstrated value to their customers. The potential 20-percent increase in reliability along with improved wildlife conservation resulted in a “turn the volume up” return-on-investment for AEL&P with a 25-year life expectancy. The decision was easy when compared with other alternatives like recurring transmission outages or a structure redesign project many magnitudes more.
Orders to proceed with the manufacturer were placed.
A short time later, linemen where uncrating the hundreds of green polymer pieces in Lemon Creek Substation. Comparing detailed packaging labels with depicted photograph design sheets made it easy to determine where individual pieces go. Each piece has two halves hinged together on one end. They can be installed or removed on energized equipment by qualified linemen, but AEL&P elected to de-energize Lemon Creek Substation for improved safety and reduced time.
Once in place, the pieces are held together with pushpins like the ones holding up molded interior panels in automobiles. The line crew repositions the Altec bucket truck to install another piece. Existing wildlife protection products sometimes held on with vinyl tape or zip ties were removed in places to prepare for the new green approach. The crew commented on the noticeable difference in desired fit and appreciated the detailed instructions. Pieces covering buss connectors extended down and around the support bushing’s first insulator skirt. A 69 kV USCO air break switch now has a new cover over its metal base and linkage arms, yet still allows for the necessary movement to operate. No gaps allowing curious beaks to poke into were found on the Cooper voltage regulator bushings. During three workdays, 444 pieces of wildlife protection products were installed.
Conclusion “Go Green”
Forest green complements drab grey electrical equipment as an employee gazes out the office window at the Lemon Creek Substation. They ask, “why green?” It turns out a green color provides better protection against ultraviolet light for a longer service life. A curious, customer passing by stopped to inquire about what the project activity and green pieces were for. The enlightened expressions on their face and happy tone said it all, “thank you!” They appreciated knowing their electric utility was working hard for them and protecting wildlife.
The most important question remains, “does it work?”
It is easy to conclude by counting the dotted bald heads of eagles perched about or hundreds if not thousands of crows and gulls that have been seen, that mother nature will be testing our new green product every day. To date, the new protection equipment is passing these daily tests. Since installation almost a year ago, there have been two incidences where protective cover was not installed. This helped validate the product, and steps have been taken to add installations at these two points. Now after one winter, the pieces have been shown to hold up against harsh windy winter weather in Alaska. The metric for evaluating success is whether Lemon Creek Substation goes one year without an eagle-related incident. This has never happened before. Continued observations are boosting confidence. A year at Lemon Creek Substation without an eagle related transmission outage is expected to be the new norm for years to come.
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