Bloom Energy Energy Server 6.5 (ES6-3250), 325 kW

Manufacturer: Bloom Energy

Bloom's current 325 kW solid oxide server, the unit physically going into the Oracle and Nebius deployments

This model is part of SecondWatt’s fuel cell research catalogue. Specifications and price observations are included where supported by sources. Equipment availability and commercial terms require confirmation.

Bloom Energy Server 6.5 dossier: 325 kW solid oxide, 65 to 53% efficiency across stack life, 55-day delivery, emissions certification and inspection guidance.

Why it matters

This is the fastest path to firm on-site power currently available in the United States, and the margin is not close. Bloom delivered a fully operational system to Oracle in 55 days against roughly three years for a gas turbine and a 61-month median from interconnection request to commercial operation. Speed, not cost per kilowatt, is what this category actually sells.

Who buys it

Hyperscale, colocation and neocloud data center operators buying firm on-site power on a schedule the grid cannot meet, plus industrial and institutional sites that need generation permitted where combustion equipment cannot be. Bloom has contracted an Oracle master agreement of up to 2.8 GW, a 328 MW agreement with Nebius, and 73 MW operational with 35 MW installing across 19 Equinix data centers in six states.

Role in the data center

Primary on-site generation for data halls, deployed in arrays of tens to hundreds of units, running grid parallel or as a microgrid with no water consumption and no combustion permit.

Key specifications

Technical summary

Rated output: 325 kW net AC (platform spans 50-325 kW in 5 kW steps) Electrical efficiency: 65-53% LHV net AC cumulative; 54% average lifetime Heat rate: 5,811-7,127 Btu/kWh HHV Total efficiency with heat capture: above 90% Fuel: natural gas at 12-18 psig; biogas, blended hydrogen or hydrogen on request Emissions: NOx 0.003, CO 0.013, VOC 0.01 lb/MWh; SOx negligible; CO2 679-833 lb/MWh Dimensions: 29 ft 5 in x 4 ft 4 in x 8 ft 2 in; 28,745 lb Output: three-phase 480 / 415 / 400 V; grid parallel or microgrid Load following: 40 to 100 percent almost instantaneously; no water in normal operation Standards: ANSI/CSA FC1-2014, UL 1741, UL 1998, IEEE 1547-2018, CARB DG-058 to 2029

Major variations

One platform across 50 to 325 kW in 5 kW increments, with linear, back-to-back and power tower site configurations and an optional heat capture package. The Be Flexible load-following capability is an attribute of the platform rather than a separate build.

Pricing and availability

Trend: up Lead time, new: 55 days observed on an Oracle delivery; six to nine months typical. Lead time, used or refurbished: No used or refurbished unit listed as of August 2026.

Published cost benchmarks

Cost figures from filings and published studies. They describe budgets or project costs, not equipment prices.

• $1.67M · ES6-3250US5002SNASK10-A

Supply, delivery and overhaul

• stack replacement (solid oxide media exchange): roughly 5 years

Lifecycle and maintenance

Solid oxide stacks are the consumable and the manufacturer controls them. Bloom reports a fleet of more than 20,000 fuel cell modules deployed since 2009, with modules from 2014 and 2015 showing a median recorded life of 4.9 years, more than 900 running past 5 years and a maximum to date of 7.7. Replacement is a manufacturer operation performed on site in under an hour, after which title to the removed module passes back to the manufacturer and the hardware goes to its own repair and overhaul centre. Contracted service runs 5 to 20 years and covers filter and adsorbent replacement alongside periodic fuel cell replacement, and the dollar rate per kilowatt is redacted in Bloom's public filings.

Thermal and emissions profile

Fuel cells generate without combustion, and that is the whole regulatory argument for siting them where an engine or a turbine cannot be permitted. California's distributed generation certification regulation sets 0.07 lb/MWh NOx, 0.10 CO and 0.02 VOC for fossil-fuelled distributed generation, and current products certify far below it, at 0.003 lb/MWh NOx for Bloom, 0.01 for FuelCell Energy and 0.02 for HyAxiom. Sacramento's 2024 best available control technology determination classifies those limits as achieved in practice and allows a combined heat and power credit of one MWh per 3.4 million Btu of recovered heat. Carbon dioxide is not eliminated: a natural gas fuel cell emits 679 to 1,006 lb/MWh electric-only, falling to 496 to 567 with full heat recovery.

Common failure points

• Stack degradation — Cumulative electrical efficiency falls from 65% toward 53% LHV across module life
• Title reversion on replaced modules — Every swapped fuel cell module reverts to the maker by contract, so a used unit may be missing its stacks
• Thermal cycling — High-temperature ceramic stacks tolerate a limited number of shutdowns and no maker publishes an allowance
• Sulfur and siloxane contamination — Sulfur deactivates catalysts and siloxanes deposit silica across anode surfaces
• Certification lapse — A California siting certification issued to the maker expires on a schedule the buyer does not control
• Service dependency — Third-party service is contractually barred on financed fleets and only the maker supplies stacks

Inspection checklist

Chain of title — establish whether the seller holds title or a project company does; Bloom contracts carry a right of first refusal at section 3.6 Repurchase right — get a written waiver; the contractual repurchase value is the greater of fair market value or 100% of purchase price reduced annually Module inventory — confirm which fuel cell modules are physically present; replaced modules revert to the maker under section 4.04 Measured heat rate — test against the 7,550 Btu/kWh minimum efficiency level in Bloom's own contracts and the 5,811-7,127 datasheet band Efficiency band — published cumulative efficiency runs 65% down to 53% LHV, so a mid-life unit is not a 65% machine Module age — Bloom reports a median recorded module life of 4.9 years and a maximum of 7.7 across more than 20,000 modules Thermal cycle count — the DOE lists limited shutdowns as an explicit challenge for stacks running at 500-1,000 degrees C, and no maker publishes an allowance Fuel quality history — total sulfurs above 5,000 ppbV average or H2S above 1,000 ppbV average exceed the published natural gas limit Siloxane exposure — 10 ppm of D5 caused total solid oxide failure in 30 hours at 1,000 degrees C in the Argonne fuel quality work Ammonia and halogens — the natural gas specification limits are 40 ppmV ammonia and 0.28 micrograms per cubic metre halogens Regulatory status — confirm a live CARB executive order covers the exact model; DG-044 for the ES-5 lapsed on 2026-03-27 Service entitlement — get a written service quotation first; third-party service is barred at section 10.01 of the standard agreement Operating data — request the remote monitoring history, which the maker holds under a 5 to 20 year service term Site scope — gas polishing media, wastewater and permitting sit outside maker scope, and cleanup ran about 1.8 cents per kWh in the Argonne 300 kW case Removal and rigging — a 325 kW unit runs 28,745 lb across 29 ft 5 in, so verify crane access and transport width

Procurement channels

Direct from Bloom, or through third-party financing as a power purchase agreement, capacity agreement, lease or energy-as-a-service contract. There is no independent dealer channel and no secondary channel: removed fuel cell modules go to Bloom's own repair and overhaul centre and return to the field.

Regional notes

Certified for California siting under CARB Executive Order DG-058 to 2029, with IEEE 1547-2018, UL 1741 SB and California Rule 21 interconnection compliance. International interconnection listings include CEI 016, KEPCO, G99, C10/113 and VDE.