From Signed Agreement to Energization: The Data Center Power Timeline

Developers use “time to power” for the period from the first interconnection request to the date the utility can deliver contracted megawatts to the site. That span covers load studies, transmission planning, utility equipment procurement, line and substation construction and regulatory approvals.² This guide covers the back half: from a signed commitment to the day the site is energized and then to full load. The front half is covered in our guides to the large-load interconnection process and the utility load study.

Three dates matter and are often confused:

• Backfeed: the utility first energizes the customer’s substation or service equipment so the site can test and commission, usually at little or no load.
• Energization or in-service: permanent service begins and the meter is set; at Dominion, this is the electric service agreement stage.¹
• Full load: the date the contract allows the full contract demand, often years later under a ramp schedule.⁷

Few utilities go straight from study to a single service contract for a large campus. Dominion Energy, which serves the largest U.S. data center market, uses three stages.¹ A substation engineering letter of authorization pays for detailed design; it is not a commitment to proceed, but it requires a $250,000 deposit, places the project in the engineering queue and typically takes 9 to 12 months.¹ A construction letter of authorization starts building substations and other facilities, and the customer is responsible for costs if the project is abandoned; Dominion puts the average substation at about $25 million.¹ The electric service agreement is the stage at which a meter is set and power flows.¹

The scale of the pipeline explains why each stage matters. Dominion reported nearly doubling the data center capacity it had under contract, to about 40 GW.⁸ With that much in line, a missed deposit or slow design approval can move a project behind others.

Elsewhere, the service agreement itself carries the long-term commitment. Ohio regulators approved AEP Ohio’s data center tariff on July 9, 2025: new large data center customers pay for at least 85% of subscribed demand for up to 12 years, including a four-year ramp, must show financial viability, and owe an exit fee if they cancel.⁷ Our guide to large-load tariffs and electric service agreements compares these terms across utilities.

Once construction is authorized, the critical path usually runs through equipment, not crews. Industry reporting in 2026 put generator step-up transformer lead times above 160 weeks in the first quarter, up from an average of 143 weeks in 2024, and noted growing deficits in circuit breakers and switchgear as data center construction pulls on the same supply.⁴ Electrical contractors describe the same pattern: power delivery, not building construction, is the bottleneck, with large power transformers taking two to four years from most manufacturers.²

Utilities have responded by ordering earlier and reserving manufacturing slots, which is one reason they ask for construction-stage commitments before buying.⁴¹ The utility’s scope typically includes:

• New or upgraded transmission lines, with rights-of-way and any state siting approval.
• A utility switchyard or substation, with transformers, breakers, protection and metering.
• Network upgrades elsewhere on the system identified in studies, which can finish later than the local work.

See our guide to transformer and switchgear lead times for procurement detail, and transmission upgrades and cost allocation for who pays.

While the utility builds, the developer builds its own side: the customer substation if it owns one, medium-voltage distribution, generators, UPS systems and the buildings. The two schedules have to meet at a single point, the backfeed date, and slippage on either side wastes the other’s work. Whether the utility or the customer owns the substation changes who controls that schedule; see utility-owned vs. customer-owned substations.

Construction power is a separate, smaller service. Sites often start with a distribution-level temporary feed or rented generation. When the permanent grid connection runs late, some hyperscale projects have rented large temporary power to keep commissioning on schedule; one supplier describes a 60 MW temporary installation for exactly that purpose.⁹ Our guide to bridge power and on-site generation covers longer-term options.

Backfeed is the first time utility power reaches the site. The utility and the owner’s electrical team agree on switching procedures, confirm protection settings, and energize equipment step by step. On large data center substations, contractors describe multiple “check-out” energizations as pieces of equipment are commissioned, each with its own method of procedure, as the substation moves from de-energized to energized.⁵

Facility commissioning then follows a recognized ladder of levels. The commissioning authority witnesses factory tests of critical equipment before it ships; equipment is then installed, started up and tested individually; and the program ends with an integrated systems test, which demonstrates that the facility as a whole performs against the owner’s requirements.⁶

Grid operators now want a say in this stage too. NERC’s May 2026 Level 3 alert asks utilities and grid operators to establish a commissioning process for computational loads, alongside modeling and protection requirements.¹⁰ In Texas, ERCOT’s ride-through rules for large computational loads took effect August 1, 2026.¹¹ Expect energization to depend on proving that UPS and transfer settings match what was modeled; our guide to NERC reliability and large loads explains why.

Energization rarely means full capacity. Utilities sequence load to match their own upgrades, and contracts formalize it: AEP Ohio’s tariff builds a four-year ramp into its 12-year term.⁷ Network upgrades identified in studies may finish after the local substation, so the first phase can be limited until they are in service. A realistic plan aligns building phases, IT deployment and the contract’s ramp, as described in our guide to load ramp schedules.

The minimum bill usually follows the ramp, so a campus that fills more slowly than its ramp pays for power it does not use.⁷ That makes the ramp a commercial decision as much as an engineering one. A buyer should model three cases: tenants arrive on plan, arrive a year late, or one building is never fitted out. The gap between the contracted ramp and realistic absorption is the exposure the owner carries, and lenders and tenants will ask about it. If the utility allows it, a slower contractual ramp with an option to accelerate is often worth more than the earliest possible full-load date.

1. 01Get the utility’s stage-by-stage process in writing: deposits, what each letter commits you to, and when the in-service date becomes firm.¹
2. 02Ask which long-lead items the utility has already ordered or reserved, and whether early procurement can be authorized at your risk.⁴
3. 03Align your customer substation, generators and UPS deliveries to the backfeed date, not the final in-service date.
4. 04Plan commissioning early, including any grid operator tests and model submissions, so energization is not held up at the end.¹⁰
5. 05Match the contract ramp to a realistic leasing and fit-out plan, since the minimum bill follows it.⁷
6. 06Decide whether temporary or bridge power is worth carrying if the permanent connection slips.⁹

For a landowner, the practical question is how far along this ladder a site’s power already is. A parcel with a construction-stage commitment is very different from one with only a study request. If you want an outside read on where a site stands, you can get a site reviewed or start with our power timeline guide.