Transmission, grid and interconnection

Why the concentration exists

Interconnection is the process by which generators and large loads apply to connect to a transmission system and undergo technical studies to identify required upgrades and allocate costs. Regional Transmission Organizations and Independent System Operators run these queues in the United States, with the country's bulk power network organised into three major interconnections: the Eastern Interconnection, the Western Interconnection, and ERCOT.[3][6]

Supply of transmission capacity is concentrated because new high-voltage lines take roughly eight to 12 years to build, primarily because of permitting procedures. Large power transformers and substation equipment are also in critically short supply, with lead times stretching far beyond historical norms, which locks in long completion timelines for any project that clears the queue.[2]

What the evidence shows

Who supplies it

Hitachi Energy, a wholly owned subsidiary of Hitachi, Ltd., is described as the world's largest transformer manufacturer by installed base, portfolio range, manufacturing capacity, and market coverage. The company is headquartered in Zurich, Switzerland, and its portfolio covers HVDC transmission systems, power transformers, switchgear, digital substations, grid automation platforms, and power quality solutions.[1][12][13]

Siemens Energy is another leading supplier of power transmission technology and services, and Williams develops and operates behind-the-meter power solutions for large energy customers including data centers. The US electric power transmission and distribution market reached USD 89.9 billion in 2024, with the transmission segment accounting for 70% of revenue, and incumbents American Electric Power, Duke Energy, and PPL Corporation invested in transmission modernisation and expansion in 2023.[4][14][18]

What it depends on, and what depends on it

Transmission sits between power plant output and data center input and is built from overhead lines, underground cables, substations, HVDC links, and grid management systems. The US network spans over 7,300 power plants, nearly 160,000 miles of high-voltage lines, and millions of miles of low-voltage distribution, connecting 145 million customers across the lower 48 states.[7]

Behind those high-voltage lines, transformers are the first major conversion point in a data center electrical distribution system, stepping down medium-voltage utility power to usable levels, and legacy transformer manufacturers are routinely quoting 52 weeks or more for made-to-order units. For hyperscale sites, three-phase AC is the standard at the grid interface because the overlapping waves deliver more stable voltage and more efficient power transfer.[15]

Where it sits in the stack

53 upstream · 4 downstream

What would break it

Behind-the-meter generation is emerging as the principal workaround for hyperscalers, with natural gas bridging the most common near-term deployment and operators in West Texas planning to bridge to grid power once transmission infrastructure catches up. Williams develops and operates such behind-the-meter power solutions for large energy customers including data centers, and the 20,840-Nvidia-H100 cluster described in one industry source requires about 25.9 MW of critical IT power capacity.[8][14][16]

What to watch

FERC's Order 2023, adopted in July 2023, requires interconnection reforms including a cluster first-ready, first-served approach in place of serial first-come, first-served, higher deposits and readiness requirements, and stricter timelines with penalties. SPP has moved to a new CPP process that sets GRID-C rates and Planned Interconnection Locations on a three-year cycle, after its legacy process saw 60% of proposed generation projects cancelled as cumbersome, time-consuming, and expensive.[5][9]

Several large transmission projects have specific commissioning targets, including the USD 3.2 billion North Plains Connector, where Minnkota Power Cooperative has secured 150 MW and operations are expected in 2032. Hitachi Energy and Grid United announced a collaboration in March 2024 to deliver HVDC technology for projects interconnecting the eastern and western US grids, and AI-powered tools can accelerate interconnection studies by as much as 80%.[10][11][17]

Related nodes

No other tracked node in the atlas currently shares this parent.

Sources

1. gridunited.com · 2025-08-26T16:52:26
2. energy.stanford.edu
3. sustainabilitydialogue.uchicago.edu · 2025-07-15T20:28:02
4. siemens-energy.com
5. emp.lbl.gov
6. eia.gov
7. epa.gov · 2016
8. newsletter.semianalysis.com
9. utilitydive.com
10. hitachienergy.com
11. publicpower.org · March 25, 2024
12. industrialsustainabilitymonthly.com · March 2026
13. hitachi.com · 2024
14. williams.com
15. gigaenergy.com · 4.23.2026
16. datacenterhawk.com · 2/19/2026
17. renewableenergyworld.com
18. psmarketresearch.com · 2024