This Spring MEA began a siting and routing study to identify locations for two new substations and a route for constructing a 115 kilovolt (kV) transmission line between the existing McRae Substation to the existing O’Neill Tap to support population centers between and above the Palmer and Wasilla core areas. Based on recent system planning studies, the load growth in MEA’s service area from Palmer-Fishhook to Pittman requires MEA to install additional transmission and substation facilities to meet current and future power loads. Due to the increased population in the area coupled with an aging power-delivery system, MEA has developed a long-range plan to construct and upgrade infrastructure that will increase capacity and provide alternate, redundant transmission routing to its substations. Having these alternatives and redundancies in place will increase power reliability for our members and prevent future power load issues which could be costly and timely to fix.
Over the past 10 years, the Mat-Su population has increased by more than 20,000. The Alaska Department of Labor and Workforce Development projects an additional 65,000 people in the Mat-Su by year 2045. It is anticipated that growth will be primarily residential, with some commercial growth as well. MEA has identified the current power improvement study area based on results of our system studies indicating where power and infrastructure is most needed to bring reliable power to our members.
Currently, the McRae Substation is fed from a radial transmission line, which means there is only one power source for a group of customers—a power failure on that line would interrupt service to customers. Providing an additional transmission line into the McRae Substation would loop in the transmission and increase reliability. The new transmission line will also provide a parallel path for power to flow from MEA’s Eklutna Generation Station into the Wasilla area to increase capacity and provide redundancy in the event of an outage that affects the entire system.
Similar transmission lines can be seen along the Palmer-Wasilla Highway.
The transmission line MEA is considering to build and operate would be a 115-kV overhead, transmission line on wood single-pole structures. The pictures shown above are examples of the transmission lines MEA is considering including a single circuit transmission structure with distribution underbuild and/or a wood pole transmission line with double circuit. The standard width of the transmission line right-of-way is typically 100 feet of clearance around the lines and structures; part of the right-of-way could include existing roadways that already have land cleared around them.
MEA has built similar 115-kv transmission lines to serve residential customers including along the Palmer-Wasilla Highway.
The transmission line routing criteria includes:
• Use existing compatible rights-of-way such as paralleling other transmission lines, railroads, and other utility corridors.
• Parallel property lines, section lines, or natural or cultural features rather crossing through properties.
• Minimize effects on private property owners. MEA will remain cognizant of effects that facilities may have on communities, including social and economic effects.
• MEA will maximize the use of existing access and minimize construction of new access roads where feasible.
• MEA will look at sites for the substations (within the siting areas) and alternative routes for the transmission line that are technically feasible from the standpoint of design, engineering, and constructability.
• The route alternatives need to facilitate locating new substation sites. As mentioned, identifying preliminary substation sites will occur simultaneously with identifying route alternatives for the transmission line.
• MEA will need to consider the costs associated with the substation sites and alternative transmission line routes, including the initial capital costs of constructing the facilities as well as the long-term operational costs.
In addition to the transmission line route, MEA is also studying two sites to build and construct residential substations. This image above shows the preliminary siting areas for the two proposed substations in the Meadow Lakes and Palmer-Fishhook areas.
Why have these areas specifically been identified for substations? MEA’s transmission and distribution system planners conducted an electrical load analysis to determine the geographic areas where the new substations are most needed to support the existing power load and found the following results:
• The Meadow Lakes area to the northwest of Wasilla is experiencing massive power load growth with several large subdivisions being built.
• Additionally, the Palmer-Fishhook area has grown considerably in recent years as well increasing load growth.
• MEA’s distribution system requires reinforcement with additional substations that are closer to the load in order to support the nominal voltage in these areas. These substations will reinforce the system to be more reliable now and in the long-term.
MEA has some important considerations when looking at potential placement of a residential substation. The substation siting criteria includes:
· The substation sites are located where the need/power load is (for example a substation that is meant to serve residential customers in Meadow Lakes cannot be placed in Willow).
· To accommodate the facilities and equipment required for a substation, available land should be a minimum of 2 acres.
· The preference is to locate on undeveloped land such as vacant, industrial, or commercial lands. The potential sites should be near a road for year-round access to the site and 100-year floodplains should be avoided.
This diagram shows the sequence of steps in the substation siting and transmission line routing process. The bulk of the preliminary siting and routing was conducted in the Spring. MEA has identified the general study area based on results of system studies indicating where the power is most needed. Within this study area, we are collecting existing and planned land use data and environmental resource data, and working with different agencies such as the Alaska Department of Transportation to get important information. We are also starting our public and member outreach process now because we are a member built-and-led electric co-op; our members’ feedback and ideas are important to us as we plan for our future power generation.
Additional timeline events include:
• The comparison of alternative substation sites and transmission line routes will occur from April through June 2021.
• Based on comments received from the agencies and public, final siting and routing will be July through October 2021.
Members can contact us and provide their feedback about the siting and routing study by emailing us at: firstname.lastname@example.org
MEA hosted its first public Open House for this study on Wednesday, May 19th, 2021 at the Government Peak Chalet from 6:00 p.m. to 8:30 p.m. The Open House included stations where members can learn about various phases and aspects of the project, ask additional questions, and provide feedback. A second Open House will be held in the Fall to share with members the final siting and routing options.
MEA has conducted two sessions with its project community Focus Group to put together some preliminary route links for a transmission line and substation sites. Additionally, we have worked with local agencies and tribal governments to identify a variety of factors including wetlands, parks, private airstrips, residences, and other valuable information to create maps for project development.
Focus Group members were asked to evaluate a variety of factors (such as residences, airstrips, trails, etc.) and assign a sensitivity level from low to very high. Sensitivity is defined as the measure of probable adverse response of each resource to potential direct or indirect effects associated with construction, operation, and maintenance of a transmission line or a substation site. Areas highlighted in orange show a higher sensitivity level compared to areas shown in blue which have a moderate/low sensitivity level. Based on the sensitivity levels, opportunity routes were developed (in the blue lines) to show areas with the greatest amount of probability to construct and build a transmission line with the lowest amount of impact. To view a higher resolution of these maps, please click here (.pdf).
Following the opportunity areas, preliminary route links were developed (mostly on top of the opportunity areas). Notice that multiple route links have been identified but ultimately one single route will be created to connect from the existing O’Neill Tap to McRae Substation and the two residential substations that are sited in the large round circles on the map. Each route link has been assigned a number and we ask for feedback from members on their preferred route links to connect the transmission line from east to west on the preliminary route map. For example a member could write: “I prefer the “10” route over the “5” route in the Fishhook area because it does not appear to be near any highly sensitive areas and landing strips.” To view a higher resolution of these maps, please click here (.pdf).
We have been getting a lot of great questions from members about different aspects of the project. To review the commonly asked questions and answers, please click here (.pdf).