The goal of this potential R&D effort is to support the development of technologies that fast-track the manufacturing of large power transformers (LPT) and other substation components, while increasing their modularity, performance, functionality, and power density. ARPA-E is seeking information at this time regarding transformative, scalable, and rapidly deployable technologies that could: - Reduce the cost, lead time, and size of substation components; - Reduce the requirement for critical materials in substations and the grid; - Improve the power capacity of existing infrastructure; - Improve the stability and resilience of the grid; and - Enhance protection of substation assets from cybersecurity threats. ARPA-E is requesting information about substation-related problems and the technological innovations that could address those problems. While significant and wide-ranging opportunities for improvement exist, ARPA-E programs seek to identify specific priority areas for technology development to make maximum impact. Therefore, this RFI solicits input from a wide range of disciplines and stakeholders such as power systems and power electronics experts, transformer manufacturers, substation developers, magnetic material scientists, energy storage experts, and other related communities to explore innovative and disruptive ideas related to active substations. ARPA-E is interested in input related to substation planning, design and commissioning, magnetic and copper material usage, and system resilience. ARPA-E is also interested in large power transformer-related challenges such as supply chains, manufacturing, and transport. It is expected that respondents will inform the agency of key components or system-level areas where accelerated advancements are needed. Example component areas of interest include, but are not limited to, magnetic and dielectric materials, bushings, electric field management, magnetic flux materials, thermal designs, and winding insulation. Example system-level solutions of interest include, but are not limited to, flexible (hybrid) power transformers with modular power converters, solid-state transformers for high-voltage applications, hybrid transformers with integrated energy storage, modular transformer designs with basic transformer blocks, and mobile substations for capacity and resilience management. To view the RFI in its entirety please visit https://arpa-e-foa.energy.gov.