US: 80% import reliance of power transformers delays hydropower infra upgrades

The United States is facing nine major supply chain challenges that could delay the rehabilitation of its hydropower infrastructure, according to a new report from the National Laboratory of the Rockies (NLR). The report has examined the difficulties hydropower operators encounter when upgrading or replacing large power transformers (LPTs). These custom-built devices raise the voltage of electricity generated by hydropower turbines, allowing it to travel efficiently across long-distance transmission networks. Their importance extends beyond hydropower, as more than 90% of the electricity consumed in the United States passes through high-voltage transformers at some stage. Transformer deliveries can take five years One of the most serious challenges identified in the report is the time required to procure new transformers. A typical LPT rated at 100 megavolt-amperes takes approximately 2.5 to three years to acquire. Lead times for extra-high-voltage units can extend to five years because only a limited number of facilities worldwide can manufacture them. Transformer prices sharply increased by approximately 80% in 2025 compared with 2021 levels, according to the report. A single unit can now cost as much as $10 million. These pressures come as demand rises across the power sector. Although domestic manufacturing and assembly capacity has expanded in recent years, the report found that it has not grown quickly enough to meet current requirements. US manufacturers also depend heavily on international suppliers. Approximately 80% of the raw materials used in domestic LPT production, including grain-oriented electrical steel and refined copper, are imported. Changing trade conditions could further increase the baseline costs of copper and steel, adding uncertainty to transformer procurement. Remote dams create transportation problems Delivering an LPT to a hydropower facility presents another layer of difficulty. Many dams are located in isolated regions surrounded by rugged terrain, making them considerably harder to reach than conventional power facilities. Transformers require specialized vehicles and heavy-duty trailers capable of carrying oversized loads. However, the United States has a limited domestic fleet of such equipment. Transportation routes must also be planned carefully and require special permits. Permitting and regulatory procedures can produce additional delays, particularly when an operator must remove an existing transformer before installing its replacement. Federal contracting rules and domestic-content requirements could also create near-term bottlenecks while US production capacity remains limited. Report could guide domestic investment The NLR study builds on the US Department of Energy’s broader Hydropower Supply Chain Gap Analysis, which previously identified five gaps affecting the domestic industry. DOE’s Hydropower and Hydrokinetic Office funded the follow-on study to provide a closer examination of the LPT supply chain. Researchers used feedback from hydropower industry participants to define the nine challenges. The findings could help shape federal policies, incentives, lending programs, workforce initiatives and investments intended to expand US transformer production. Strengthening the domestic supply chain will be important for new construction as well as upgrades, refurbishments and relicensing work at existing facilities. Hydropower currently provides more than 6% of total US electricity generation, making the availability of critical transformers essential to its continued contribution to the grid. The report is titled as Large Power Transformer Supply Chain Gap Analysis and Domestic Content Strategies for Hydropower Rehabilitation. Recommended ArticlesGet the latest in engineering, tech, space & science - delivered daily to your inbox.Atharva is a full-time content writer with a post-graduate degree in media & amp; entertainment and a graduate degree in electronics & telecommunications. He has written in the sports and technology domains respectively. In his leisure time, Atharva loves learning about digital marketing and watching soccer matches. His main goal behind joining Interesting Engineering is to learn more about how the recent technological advancements are helping human beings on both societal and individual levels in their daily lives.