Alaska Energy Authority details transmission upgrades, Dixon Diversion and HVDC subsea cable plans

Curtis Thayer, executive director of the Alaska Energy Authority, told the Senate Resources Committee on Jan. 24 that AEA is pursuing multiple projects to improve rail‑belt reliability, reduce line loss, and add renewable and dispatchable capacity.

"Bradley Lake... supplies Alaska 550,000 Alaskans on the rail belt and about 4 and a half cents a kilowatt," Thayer said, describing Bradley as the state's largest hydro facility and a foundational asset for planned upgrades. He outlined three priority project types: increased hydropower deliverability through the Dixon Diversion, transmission upgrades (Sterling to Quartz Creek and other lines), and a high‑voltage direct‑current (HVDC) subsea cable to create a redundant link between the Kenai Peninsula and Beluga/Anchorage.

The nut graf: AEA presented a combined approach—generation, storage and transmission—to reduce rail‑belt dependence on natural gas. Key near‑term projects are (1) the Dixon Diversion to raise Bradley Lake output, (2) Sterling‑to‑Quartz Creek transmission upgrades already in construction, and (3) a proposed HVDC submarine cable (GRIP) intended to connect Nikiski to Beluga, which AEA says is on schedule for engineering and preliminary work.

Dixon Diversion: AEA is studying a directional drill (14‑foot diameter, ~5 miles) to divert receding glacier flow into Bradley Lake, raise the dam by 14 feet, and increase Bradley's capacity by roughly 50 percent. Thayer said the project could add roughly 60 megawatts and displace about 1.5 billion cubic feet of natural gas in 2030. He estimated a planning/capital cost near $342 million and reported AEA hopes to submit required materials to FERC and complete permitting steps to enable construction as soon as the late 2020s, subject to FERC timelines.

Transmission and GRIP/HVDC: AEA described a $90 million Sterling‑to‑Quartz Creek upgrade (40 miles) that is under construction and a larger HVDC submarine cable project the presentation listed at approximately $413 million. Thayer said the state and utilities have identified $62.7 million in matching funds toward a federal match of about $206 million for the offshore cable project, and preliminary engineering is underway. He said subsea cable preliminary estimates are coming in below original expectations, and AEA plans two parallel cables for redundancy with an estimated 50‑year lifespan.

Battery and ancillary services: AEA described battery energy storage systems deployed or planned in Homer, Anchorage and Fairbanks and said AEA has arranged $28 million in support over 15 years to help defray battery costs for the three utilities. Thayer said batteries provide frequency support, dampen oscillations, and reduce the need to hold gas generators spinning as reserve.

Railroad Transmission Organization and tariff work: Thayer said HB 307 created a transmission governance structure and new AEA authorities; AEA has submitted model bylaws to the Regulatory Commission and is developing an open, non‑discriminatory transmission tariff. He gave a target of July 1 to finish the tariff draft for filing; he estimated RCA review could take months and suggested a realistic window for regulatory action might extend into early next year.

Federal funding note: Committee members asked whether the presidential pause on some federal infrastructure actions would affect these projects. Thayer said the current executive review is a routine pause for incoming administrations and that projects already appropriated by Congress and signed by the president are unlikely to be de‑funded; he said applications in process could be delayed during the 90‑day review.

Ending: Thayer said the combined portfolio — hydropower (Dixon), transmission upgrades (Sterling‑Quartz and subsea HVDC), battery storage, and a regional transmission organization — would create thousands of construction jobs, lower long‑term costs and allow more renewables on the rail belt. He asked the committee for continued legislative support and offered to return with updates.