For years, the hard part of building a data center was finding land and fiber. Now it is power, and utilities have started writing the terms. A large load tariff is the rate schedule and contract package a utility uses for customers that want tens or hundreds of megawatts. These tariffs decide how much cash you post before a study begins, how long you must pay for power you may not use, and what you lose if the project slips.
Texas just put the most detailed version into law, and Missouri and Wisconsin are moving the same way. If you are a developer, an operator, or the CFO signing the check, here is what a large load tariff asks of you and which terms deserve a hard look.
What a Large Load Tariff Is, and Why Utilities Want One
When a single customer asks for the electricity of a small city, the utility may need new substations, transmission lines and generation. If that customer walks away, someone else pays for the stranded build-out. Large load tariffs exist to keep that someone from being every other ratepayer.
The tools are consistent across states: study fees, collateral, long minimum terms, minimum-demand charges that work like take-or-pay obligations, and penalties for withdrawing or shrinking a request. The details are where the money is.
Texas Sets the Template: $50,000 per Megawatt Up Front
The Public Utility Commission of Texas adopted 16 TAC §25.194, which implements Senate Bill 6 and took effect October 8, 2026. It applies to customers that have not energized and seek a new interconnection of 75 MW or more at a single site, certain expansions, or co-location with a generator. Key requirements, from the rule text and the commission’s adoption order:
- Before any study. The customer signs an “intermediate agreement,” pays a $100,000 study fee and posts security of “$50,000 per MW of the requested peak demand.” A 300 MW request means $15 million in security before the grid operator studies it.
- Attested disclosures. Site control, water use, backup generation, power supply plans and any “substantially similar” request elsewhere in Texas must be disclosed and attested by an officer with binding authority. False or incomplete information can bring penalties or loss of allocated capacity.
- A 60-day clock. Within 60 days after the study report allocates capacity, the customer must sign and fund a standard agreement or lose its place.
- Bigger security at signing. At that point security is the greater of $50,000 per MW of contracted demand or the system-upgrade costs allocated to the customer. Direct interconnection costs are paid in cash and are “not refundable.”
- Exit costs. Withdrawing after capacity is allocated generally costs 20% of the related security, on top of costs the utility cannot cancel. Security comes back in stages: 20% at energization, the rest in 20% steps as billing milestones are met.
One major piece is still open. The agreement must include a promise to pay a “large load minimum billing demand,” but the commission left the details of that charge to a separate rulemaking. Anyone signing now is agreeing to a number that has not been set.
The Midwest Is Following the Same Path
Missouri. Senate Bill 4 (2025) added a requirement to RSMo 393.130 that larger electric utilities file schedules for customers “reasonably projected to have above an annual peak demand of one hundred megawatts or more.” Smaller utilities use a 50 MW threshold. The schedules must reflect those customers’ “representative share of the costs incurred to serve” them.
Wisconsin. On April 24, 2026, the Public Service Commission announced its decision on We Energies’ Very Large Customer tariff (Docket 6630-TE-113). According to the PSC, it extended the minimum initial term to 15 years, lowered the eligibility threshold from 500 MW to 100 MW, removed an option that would have had data centers pay only 75% of generation costs, and required revisions addressing transmission cost shifting. The written final order controls over the press summary.
Illinois regulators are working through the same questions. Expect each utility’s large load tariff to differ in the numbers while sharing the structure.
7 Critical Large Load Tariff Terms to Model Before You Sign
- Minimum demand. How much capacity must you pay for whether you use it or not, and for how long? Model the bill if your tenant delays move-in by two years.
- Contract term. A 15-year minimum is longer than many tenant leases and most construction loans. Match the term to your financing and offtake.
- Collateral form. Texas accepts only cash, a guaranty from a BBB-/Baa3-rated guarantor, or a letter of credit from an A-/A3-rated bank. Unrated sponsors need a plan, and letter-of-credit fees belong in the pro forma.
- Withdrawal and downsizing penalties. Know what you forfeit if you cut the request, and when the penalty starts.
- Ramp schedule. In Texas, a material change to peak demand, phasing or point of interconnection requires a new request. A realistic phased schedule protects your queue position.
- Who the customer is. The rule reaches affiliates down to a 5% ownership level. Decide early which entity signs, holds site control and posts security.
- True-ups. Interconnection cost estimates are trued up to actual costs. Cap or at least define your exposure to overruns.
Where the Tariff Meets Your Other Contracts
A large load tariff never stands alone. Its obligations should flow into your tenant leases and colocation agreements, so a hyperscale tenant that delays shares the minimum-demand cost. Your data center land lease needs an option period long enough to survive the utility study, and your site plan must clear data center zoning. A local data center moratorium can stall a project while the tariff clock keeps running.
These tariffs are also a response to rising data center energy costs for other customers, so regulators will keep tightening them. For the full development checklist, see our data center development practice page.
What Developers and CFOs Should Do Now
- Read the actual tariff. Pull the utility’s filed large load tariff and pending dockets before you sign a land option, not after.
- Budget collateral as capital. Security at $50,000 per MW is real money tied up for years.
- Align your documents. Tenant leases, construction contracts and loan covenants should mirror the tariff’s milestones and penalties.
- Control the disclosures. Officer attestations create personal and corporate exposure. Build a diligence file that supports every statement.
- Plan for disputes. If a utility draws on security or a tenant refuses to share costs, our commercial litigation lawyers handle contract disputes.
The large load tariff is now one of the most important documents in a data center deal. Treat it like one.
Planning a large load project? Book a consultation with Howard East and have our outside general counsel team review the tariff, collateral and contract stack before you commit.
This article is for informational purposes only and does not constitute legal advice. Tariffs vary by utility and change through regulatory proceedings; Texas’s minimum billing demand charge and Wisconsin’s written final order should be reviewed directly.
