Cold-Climate and Arctic Solid-State Transformer Performance: Why Clear Space Force Station Alaska Matters

Air Force Research Laboratory’s award to Concurrent Technologies Corporation of $18 million for resilient battery storage at Clear Space Force Station, Alaska (mgrid post 8820) is one of the most consequential cold-climate solid-state transformer (SST) and battery-storage deployments in active development. Clear is located approximately 80 miles south-southwest of Fairbanks, in central Alaska, with winter temperatures regularly dropping below minus 40 degrees Celsius. The SST and BESS equipment qualified for this deployment will produce the cold-climate operational data the broader industry currently lacks.

The cold-climate thermal-management problem for SSTs is the inverse of the tropical-deployment problem documented in the Eaton-NUS Singapore Sustainable Tropical Data Centre Testbed. In hot climates the engineering challenge is removing heat from the SiC power devices, the DC-link capacitors, and the medium-frequency transformer fast enough to keep junction temperatures within design margin. In cold climates the engineering challenges are starting cold (the dielectric fluid in the cooling system thickens at temperatures below approximately minus 30 degrees Celsius), maintaining capacitor electrolyte performance, and managing condensation cycling as equipment warms after de-energization events.

The conventional iron-core transformer fleet operates at scale across cold-climate regions (Alaska, northern Canada, Scandinavia, northern Russia, sub-Arctic mining sites) and the engineering practices for cold-climate deployment are well-developed. Specially formulated insulating oils with low pour point, oversized radiator banks to handle warm-weather thermal loads with cold-weather oil viscosity, and integrated electric heating mats for cold-start operation are standard. SST architectures inherit some of these requirements (the cooling fluid in immersion-cooled SSTs has similar low-temperature pour-point requirements) but face new requirements specific to the power-electronics modules.

The military deployment context at Clear is also informative. The Air Force Research Laboratory’s award explicitly emphasizes resilience — the ability to operate through extended utility-grid disturbances, severe weather events, and physical-security incidents. The SST’s active control capabilities and the BESS’s energy storage enable an islanded microgrid mode that conventional iron-core distribution cannot provide. Other remote military installations (Eielson Air Force Base near Fairbanks, Joint Base Elmendorf-Richardson near Anchorage, multiple Greenland sites) face similar requirements and are plausibly targets for follow-on SST procurement.

The commercial implication beyond the military sector is that the cold-climate SST operational data the Clear deployment produces will be applicable to remote-region utility distribution (rural Alaska, northern Canada), to mining-industry sub-Arctic operations (Red Dog mine in Alaska, multiple Canadian Arctic projects), and to research-station applications (US Antarctic Program McMurdo Station, multiple national programs). The cold-climate SST market is materially smaller than the temperate-climate market but is the segment where the SST’s resilience advantages over conventional iron-core architectures are most visible.

Why It Matters

For defense and cold-climate operators, the AFRL’s $18 million Clear Space Force Station award puts SST and battery hardware into an environment that routinely drops below minus 40 Celsius, qualifying equipment against thermal extremes most commercial specs never test. Hardware proven in central Alaska carries reliability evidence that lowers risk perception for any critical microgrid in a harsh climate.

Critical Perspective

Editorial correction: This post is part of MGRID’s Solid-State Transformer industry coverage. As of May 2026, that body of work systematically framed manufacturer announcements, funding rounds, and laboratory demonstrations as commercial deployments. The reality is that field-deployed commercial-class SST in revenue service globally is measured in single digits, and almost every product cited in this series is at “announced” or “funded” stage, not “operational.” Readers should treat the specific claims in this post against the standards documented in our SST Industry Reality Check (the per-claim audit table maps marketing language to verifiable deployment status). The corrective article is the canonical reference for SST industry reality; this post remains published with its original framing so the editorial drift is traceable.

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