Large loads are driving costly, transformational transmission upgrades

RMI (authors Mark Lozano, Tyler Farrell, Sarah Wang, Claire Wayner, Chaz Teplin) concludes that large load interconnection is causing a surge in material and transformational network upgrades and recommends system-wide and regional-first planning and increased regulatory oversight.

• Main finding: The article documents that the large-load interconnection process is now driving a significant share of transmission investment, with an increased frequency of material ($10M–$50M) and transformational ($50M+) upgrades; it cites a proposed American Transmission Company transformational project to serve a 1.3 GW new load with estimated costs of $1.3B, and Virginia examples of a 111 MW substation upgrade costing $28 million and a 77 MW transformational upgrade costing $140 million.
• Context and evidence: This is an analytical piece (not a new project announcement) that references existing proposals, regulatory filings, and regional data: PJM load-interconnection share rose from an average 5.7% (2005–2019) to 18% (since 2019); MISO load interconnection accounted for nearly 30% of transmission spending in 2025. The article cites linked reports and planning tools (E3, PJM TCPlanner, MISO MTEP) and recommends system-wide and regional-first planning plus greater regulatory oversight to avoid piecemeal, inefficient upgrades.