FERC: US Data Centers Hit 50 GW as MISO Grows 43% Per Year
- Analysis Data Centers Grid Capacity Grid Connection & Reliability
Marin Holt
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- 5 minutes read
- 50 GW of US data center capacity was operating at the end of 2025.
- US data center capacity has grown at a 24% compound annual rate since 2020.
- The Midcontinent Independent System Operator (MISO) region experienced 43% annual growth in data center capacity.
- The average size of new data centers commissioned in 2025 was nearly 80 MW, a 3.2x increase from 2020.
50 GW of Data Center capacity was operating in the United States at the end of 2025 — 24% compound annual growth since 2020 — according to [FERC](/?p=4386) 2025 State of the Markets report released March 19, 2026. The Midcontinent Independent System Operator saw the fastest regional growth at 43% per year, more than any other US grid region.
The Data
FERC 2025 State of the Markets, released March 19, 2026, is the first FERC publication to tally data center capacity across all US grid regions. The 50 GW total covers all Data Centers interconnected to US grids. The 24% compound annual growth rate since 2020 compares to 2-3% annual demand growth for all other load categories combined, per Utility Dive March 26, 2026. Average facility size at commissioning grew from [25 MW](/?p=7494) in 2020 to nearly 80 MW in 2025.
MISO 43% annual growth stands out because the Midcontinent region was historically a secondary data center market behind Northern Virginia (PJM), Silicon Valley (CAISO), and Dallas (ERCOT). Lower land and energy costs, combined with available transmission capacity, are pulling hyperscale development away from more congested markets. MISO 2025 capacity auction cleared at a summer price of 66.50 per MW-day — 22x higher than the prior year — per Enel North America auction summary, reflecting demand pressure from new large loads.
What It Means
50 GW is roughly 6.5% of total US installed generating capacity. At 24% annual growth, data centers alone could reach 80-90 GW by 2028. The shift from 25 MW to 80 MW average facility size changes the interconnection calculus: each new data center now requires transmission studies and substation upgrades previously reserved for large industrial plants. Power quality implications scale proportionally — an 80 MW facility produces more than 3x the harmonic injection and reactive power demand of a 25 MW facility on the same distribution circuit.
The Gap
FERC 50 GW counts interconnected capacity, not operational load. Many facilities operate well below nameplate. The report does not separate AI GPU cluster capacity from traditional colocation or cloud compute, making it difficult to isolate how much harmonic distortion, reactive power burden, and subharmonic generation comes from AI workloads versus conventional IT loads.
Critical Perspective
FERC report describes what happened; it does not prescribe what should happen. MISO 43% growth is a market fact, not a policy outcome. State commissions in MISO footprint — Illinois, Indiana, Michigan, Minnesota, Wisconsin among others — have not updated interconnection or cost-allocation rules to reflect data center load characteristics, which differ materially from residential and commercial growth those rules were written for. Whether the capacity price spike to 66.50 per MW-day is sufficient to drive the infrastructure response needed is a question the report does not address.
