Best Available Technology (BAT) for Data Centers That Bring Their Own Power (Behind-the-Meter / On-Site Generation)

June 17th, 2026

By Rep. Shane Klakken, HD 37

For hyperscale AI data centers generating their own power (“Bring Your Own Power” or behind-the-meter/BTM setups), the industry is rapidly shifting away from sole grid reliance due to interconnection delays. The best available technologies in 2026 combine reliable baseload generation with high-efficiency integration to the facility.20

Top BAT Options (Ranked by Current Deployment & Maturity)

1. Natural Gas Turbines / Reciprocating Engines (Dominant Near-Term BAT)Aeroderivative gas turbines (e.g., adapted jet engines like Boom Supersonic’s Superpower 42 MW units) and advanced supercritical CO₂ turbines.
   Fast deployment (months vs. years for grid), high reliability, and dispatchable power.
   Often paired with battery storage for peak shaving and backup.20
   Widely used by Meta, xAI (Colossus), and others for full or hybrid on-site power.
   

2. Fuel Cells (Strong Clean Alternative)

• Solid oxide fuel cells (e.g., Bloom Energy) provide quiet, efficient (near combined-cycle levels), low-emission baseload power.

• Modular, quick to install (as little as 90 days), and scalable.

• Can run on natural gas now, with future transition to green hydrogen.3

1. Small Modular Reactors (SMRs) & Advanced Nuclear (Emerging Gold Standard)

• Best long-term BAT for carbon-free, 24/7 baseload power with very high capacity factors.

• Companies like Microsoft (Three Mile Island restart + SMRs), Amazon, and Google are heavily investing.

• High upfront cost and longer timelines, but excellent for reliability and low operating costs once online.0

Key Supporting Technologies

• Advanced Liquid Cooling (Direct-to-chip or immersion) — Essential to pair with any on-site generation to minimize waste heat and overall power demand (lowers PUE to 1.10–1.20 range).

• Battery Energy Storage Systems (BESS) — For grid-interactive flexibility, backup, and smoothing variable loads or renewables.

• Microgrid Controls — Sophisticated software for managing hybrid setups (gas + solar + batteries + nuclear).

Why This Matters for Montana

Data centers bringing their own power reduce strain on NorthWestern Energy’s grid but still require strong local oversight on emissions, water (for any cooling), and fuel supply. The BAT today favors modular gas turbines or fuel cells for speed, with SMR nuclear as the clean, firm-power goal for larger projects.

Communities should demand:

• Closed-loop dry cooling

• Clear efficiency targets (PUE < 1.2)

• Emissions controls

• Transparency on fuel sources

This approach allows faster deployment while aiming for lower long-term environmental impact compared to older grid-dependent models. The technology exists to balance AI growth with rural resource protection.