What does it cost to bring three-phase power to a fleet yard?
It is priced per foot of line, offset by your utility's line-extension allowance, and only your utility can quote it. The distance from the nearest three-phase primary, whether the run goes overhead or underground, road and rail crossings, and any easements you need set the construction estimate. The allowance in the filed tariff decides how much of that estimate you pay. No engineering contractor can quote this number, and a careful one will exclude it in writing — which makes that exclusion clause the first thing to look for before comparing two proposals on price per port.
Updated 2026-08-20
Why nobody but the utility can price this
A line extension is utility construction. Their crews or their approved contractors build it, their material standards govern, their easement process applies, and their estimate is the number that ends up on your invoice. An electrical contractor can tell you what it will cost to build the yard. They cannot tell you what the utility will charge to reach it, and the honest ones say so on the first call.This is the single largest source of surprise on depot projects. The customer-side scope is well understood and quotes for it are broadly comparable. The utility-side scope is unknowable until you ask, and the gap between two sites a mile apart can be an order of magnitude.
What drives the construction estimate
Two practical consequences. First, where you put the equipment is a cost lever: moving a pad two hundred feet closer to the existing primary can be worth more than any equipment decision on the project. Second, route matters as much as distance — a shorter route that crosses a highway can cost more than a longer one that does not.
What we can put a number on, and what we cannot
The ranges below are national installed-cost ranges before incentives, drawn from the commercial sources cited at the foot of this page. They are calibration for a first budget, not a quote for your site.
How to get the utility's number
The exclusion clause, and how to read a per-port proposal
The clause is not a trick. It is the correct thing for a contractor to write, because they cannot price somebody else's construction. The problem is what happens next: two proposals arrive, one excludes the utility scope and one carries a provisional sum for it, and the one that excludes it looks cheaper by exactly the amount of the risk it has handed back to you.The fix is bid levelling, and it is one email. Tell every bidder to carry an identical, clearly marked allowance for utility charges — the same figure for everyone, ideally the utility's own estimate once you have it — so the comparison reflects the work each of them is actually doing.
Cheaper answers to try before you buy the line
The schedule is the other half of the cost
Vehicles arriving before power does is the expensive failure on these projects, and it is a scheduling failure rather than an engineering one. Get the utility's answer before you sign a vehicle order, not after.There is no federal credit reducing any of this. Section 30C terminated for property placed in service after June 30, 2026 and has no federal replacement, so anything quoting a 30 percent federal offset against infrastructure cost is working from a rule that has expired. Utility make-ready programs are the layer where money may still exist, and they vary by territory.
How much does three-phase power cost per foot?
There is no national per-foot figure we would stand behind, because it moves with terrain, route, overhead versus underground, local labour and the utility's own construction standards. Ask your utility for its current estimate for your specific route, in writing. That is the only number that will appear on your invoice.
Is underground more expensive than overhead?
Yes, materially, for the same distance. Trenching, conduit or duct bank, backfill and surface restoration replace poles and conductor, and restoration across a paved yard or a public road is the part that surprises people. If overhead is permitted on your route, price both.
Can I install my own transformer and primary?
Some tariffs allow customer-owned primary and transformer arrangements. It moves capital, maintenance and replacement onto you and it changes where the meter sits. Ask whether the option exists in your territory and price it both ways, including the maintenance obligation over the equipment's life.
Will my contractor handle the utility for me?
Most will coordinate, and coordination is worth having. It is not the same as pricing, and the contract language will say so. Keep the utility correspondence coming to your own account as well, because the answer is a fact about your service that outlives the contract.
Does the allowance still apply if I lease the yard?
It can, but a lease shorter than the revenue horizon the allowance is calculated over changes what the utility is willing to allow, and a landlord's consent is usually needed for construction and easements anyway. Raise the lease term with the utility early rather than at the agreement stage.
- SolarTech — EV fleet charging guide (depot per-port range; saving from building make-ready once)
- GreenLancer — guide to commercial EV charging stations (DC fast per-port cost; infrastructure share)
- EV Connect — how much does a charging station cost (hardware versus infrastructure split)
- NARUC — directory of state public utility commissions, where line-extension tariffs are filed
- IRS — Alternative Fuel Vehicle Refueling Property Credit (Section 30C status)
Price the work inside your fence
Get the customer-side range now and set it beside the utility's estimate when that arrives. Two numbers, one budget.