The US electricity system is expected to see substantial demand growth through the mid-2030s, driven by commercial and industrial expansion, including advanced manufacturing, data centres and domestic industrial growth, alongside electrification. To assess the transmission investment needed to support this growth and broader economic and national security priorities, S&P Global Energy released the study “Powering Growth and Affordability: The Role of Transmission in Economic and National Security”, supported by the Electricity Customer Alliance and National Grid, with Converge Strategies responsible for national security and defence aspects. The study examines the scale, location and type of investment needed to meet future demand, improve affordability and reliability, and mitigate prolonged power disruptions. Under the base scenario, these demand drivers are projected to add 374 TWh of electricity consumption and over 45 GW of peak load by 2035, with higher growth under the high-demand scenario.

Broadly, the study identifies the following key benefits of transmission expansion:

  • Economic and affordability benefits: Reducing infrastructure costs and production costs, with potential savings for electricity customers through lower retail rates.
  • System reliability: Increasing transmission transfer capability and improving access to generation resources, thereby reducing dependence on more expensive local generation.
  • Resilience: Improving reserve sharing and reducing exposure to extreme weather-related electricity price premiums and regional power disruptions.
  • National security and defence: Strengthening electricity supply resilience for military installations, defence communities, mission-critical infrastructure and the defence industrial base.

The study concludes that proactive intraregional and interregional transmission development can deliver economic, affordability, reliability and national security benefits amid rising US electricity demand. Coordinated expansion offers greater system-wide value, particularly under high-demand conditions, by relieving grid bottlenecks, broadening access to generation resources, accommodating future load growth, reducing system costs and strengthening resilience.

Access the full report here