Last updated: September 10, 2026
Large-Load Utility Tariffs for Data Centers: Minimum Take, Demand Guarantees & Curtailment
Two parcels can sit on land with identical power prices on paper and still carry very different real economics once you look at which tariff applies. Utilities across the country have started filing rate classes built specifically for very large, long-duration loads — with minimum-take charges, multi-year lock-ins, and in some cases curtailment obligations attached. For a landowner or broker, knowing that these tariffs exist, and roughly how they differ, explains a lot about why a developer moves fast on one site and walks from another with similar headline power numbers.
⚡ TL;DR — Large-Load Tariffs
- • What it is: a special utility rate class, filed with state regulators, for customers above a large demand threshold — often 25 MW+
- • AEP Ohio: 85% minimum-take on contracted demand every month, 8-year minimum term, exit fees, curtailment tied to onsite generation
- • Dominion (Virginia): GS-5 uses a demand guarantee rather than a percentage minimum-take structure
- • Georgia Power: PLL-18 skips a separate demand charge entirely — customer charge plus tiered energy charge instead
- • Why it exists: utilities are hedging against developers over-contracting capacity and walking away, leaving grid upgrade costs on other ratepayers
- • Landowner takeaway: ask which utility and rate class applies to a site — it shapes how a developer underwrites the deal before they ever make an offer
Why Utilities Started Writing These Tariffs
A single hyperscale campus can ask a utility to plan for hundreds of megawatts of new demand — often more than the utility's entire existing service territory draws from a specific substation today. Utilities have to start planning transmission and generation investment years before a facility breaks ground, based on a developer's forecast. The risk is that developers sometimes submit interconnection requests for multiple competing sites at once as a hedge, intending to build only one — leaving the utility to guess which requests are real. A large-load tariff is a utility's attempt to make that guess less costly: by requiring a minimum-take commitment or demand guarantee regardless of actual usage, the tariff shifts the financial risk of an overbuilt or abandoned project back onto the customer requesting the capacity, rather than spreading it across every other ratepayer on the system.
This is a live, evolving area of utility regulation rather than a settled one — state commissions in multiple regions are actively weighing large-load tariff filings as of 2026, and the structures utilities propose vary widely even within the same region. See our guide to the grid interconnection queue for the separate process question of how long it takes to get a request studied and approved in the first place — the tariff governs what a customer pays once connected; the queue governs how long it takes to get there.
How the Major Tariff Structures Compare
AEP Ohio
85% minimum-take on contracted demand every month, applied to loads 25 MW and up. Eight-year minimum contract term with exit fees for early termination. Large loads with onsite generation must provide instantaneous curtailment synced to their own output during grid stress.
Dominion Energy (Virginia)
GS-5 rate class uses a demand guarantee — the customer commits to a guaranteed demand level that anchors billing — rather than a percentage-of-contract minimum-take. Virginia's outsized data center concentration means this tariff's evolution tends to influence how other states approach their own large-load dockets.
Georgia Power
PLL-18 has applied to large customers for more than a decade and doesn't use a separate demand charge at all — billing runs on a monthly customer charge plus a tiered energy charge, a materially different cost profile to model than a minimum-take structure.
These three utilities illustrate a wider range of approaches rather than a settled industry standard — a Dominion-style demand guarantee, an AEP-style minimum-take, and a Georgia-style flat tiered structure each carry different cost profiles for the same size of load. A developer comparing sites in Ohio, Virginia, and Georgia isn't just comparing land price and power availability — they're comparing three different rate philosophies for how much they'll owe if a facility ramps up more slowly than planned.
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Curtailment: The Other Half of the Bargain
Minimum-take charges protect a utility's revenue if a load ramps up slowly. Curtailment provisions protect grid reliability once a load is up and running, by giving the utility the right to reduce or interrupt a large customer's draw during periods of system stress — a heat wave, a generation shortfall, an unplanned outage elsewhere on the grid. AEP Ohio's tariff, for example, requires large loads that have their own onsite generation to provide instantaneous curtailment synchronized to that onsite output, meaning the facility has to be technically capable of stepping its grid draw down the moment its own generation is available to cover the gap, not on a delay.
For a developer, curtailment terms interact directly with onsite power planning — see our guides to battery storage and backup power and behind-the-meter generation for how facilities are increasingly designed to absorb curtailment events without a service interruption, rather than treating the grid connection as the sole source of power. A site that already has strong onsite generation potential — a nearby gas pipeline, favorable solar or wind resource, room for a battery installation — is more attractive under a curtailment-heavy tariff than an otherwise comparable site with none of that flexibility.
What This Means for a Landowner
- A large-load tariff is filed at the state and utility level, not the parcel level — but which utility serves your land determines which tariff a buyer underwrites against, so it's worth knowing before you're deep into a negotiation
- Minimum-take and demand-guarantee structures raise a developer's downside risk on a slow-ramping project, which can make them more cautious or more insistent on favorable option terms on land served by a strict tariff
- A site with real onsite generation potential — gas access, solar or wind resource, room for battery storage — is worth more under a curtailment-heavy tariff than a site without it, even at comparable grid power availability
- Ask a broker or developer directly which utility and rate class applies before assuming a favorable power price alone makes a site competitive
- This is an actively shifting regulatory area — a tariff that applies today may be revised as state commissions continue weighing large-load dockets through 2026 and beyond
See our guide to data center power purchase agreements for how private PPAs differ from a utility's own tariff, and how much power a data center actually needs for the underlying demand figures a large-load tariff is designed around.
Frequently Asked Questions
What is a large-load tariff?
A large-load tariff is a special utility rate class, filed with and approved by a state public utility commission, that applies to customers above a defined demand threshold — often 25 MW or higher. Instead of billing a data center under the same general industrial rate as a smaller factory, the utility applies terms built specifically for very large, long-duration loads: minimum-demand or minimum-take charges, long contract terms, exit fees, and in some cases curtailment obligations. Utilities have pushed these tariffs in response to a wave of data center interconnection requests that, if even a fraction don't materialize, could otherwise leave existing ratepayers holding the cost of grid upgrades built for load that never showed up.
What does AEP Ohio's large-load tariff actually require?
AEP Ohio's tariff applies to data center and crypto-mining loads above 25 MW and requires the customer to pay demand charges on at least 85% of its contracted capacity every month, regardless of actual usage — so a facility contracted for 200 MW pays for at least 170 MW whether it draws that much power or not. The tariff also sets a minimum contract term of eight years with exit fees for early termination, and requires large loads with onsite generation to provide instantaneous curtailment synced to their own onsite output during grid stress events. The structure is designed to prevent a developer from over-contracting capacity as a hedge and then walking away once a project stalls, leaving the utility's grid investment unrecovered.
How is Dominion Energy's Virginia tariff different?
Dominion's GS-5 large-load rate uses a demand guarantee rather than AEP Ohio's percentage minimum-take structure — the customer commits to a guaranteed demand level that anchors billing regardless of the exact percentage drawn in a given month. Virginia carries outsized weight in this conversation because it hosts the country's largest concentration of data centers, so how Dominion's tariff evolves tends to influence how other state commissions think about their own large-load dockets, even where the specific mechanics differ.
Does Georgia Power charge data centers the same way?
No — Georgia Power's Large Power & Light tariff, PLL-18, has been the standard large-customer rate for more than a decade and doesn't use a separate demand charge the way AEP Ohio and Dominion do. Instead it bills through a monthly customer charge plus a tiered energy charge, which is a materially different cost profile for a data center operator to model than a minimum-take or demand-guarantee structure. That difference matters for site selection: two states offering comparable power prices on paper can carry very different real costs once the tariff's minimum-take and contract-term terms are priced in.
Why should a landowner care what tariff a utility applies to a buyer's project?
A large-load tariff doesn't appear on your closing statement, but it shapes how confident a developer can be in a site's long-run economics before ever making an offer. A developer evaluating land served by a utility with a strict minimum-take and long lock-in term is underwriting more downside risk than one evaluating a similar site under a simpler tariff like Georgia's — which can affect how aggressively they bid, how fast they move, or whether they walk from an otherwise strong parcel because the rate structure doesn't pencil. Asking a broker or developer which utility and rate class applies to your land, and whether that utility has a large-load tariff on file, is a fair early diligence question, not a technicality.
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