Utility Interconnection Rules for EV Charging Installations

When your association decides to install EV chargers, the equipment does not simply plug into the wall and start drawing power. Adding a bank of Level 2 chargers, each pulling 7.2 to 11.5 kilowatts, can raise a building's peak electrical demand by tens or even hundreds of kilowatts. Before the local electric utility allows that new load onto its system, it must review and formally approve the connection. That review-and-approval process is called interconnection, and it is one of the most commonly overlooked steps in a multifamily charging project.

Interconnection matters because the utility owns everything from the street to your building's meter, including the transformer that steps high-voltage power down to the level your building uses. If your new chargers would push that equipment past its rated capacity, the utility may require an upgrade, a process that can add months to your timeline and tens of thousands of dollars to your budget. Understanding the rules early lets your board plan around them instead of being surprised mid-project.

Every utility publishes its interconnection and service rules in a tariff filed with the state public utilities commission. In California, for example, these are known as Rule 15 and Rule 16, covering line and service extensions; other states have equivalent documents. Your installer or electrical contractor will handle these rules on your behalf, but board members benefit from knowing the basic vocabulary so they can ask the right questions.

The first technical question is whether your building's existing electrical service can absorb the new charging load without an upgrade. This starts with a load calculation performed under National Electrical Code (NEC) Article 220, which estimates your building's existing demand, plus a review of the utility's metered peak over the past 12 months. The gap between your service rating and your actual peak is your spare capacity.

Many older buildings have less headroom than owners expect. A 1980s garden-style condo might have a 400- or 800-amp service that is already 70 to 80 percent loaded on a hot afternoon. Adding ten Level 2 chargers at full power could exceed what is left. This is exactly where load management technology earns its keep: by automatically throttling or staggering charging when the building is busy, smart charging systems can let you add many more ports without triggering a service upgrade.

Once the design is set, your contractor submits an interconnection or service-change application to the utility. For a modest Level 2 project that fits within existing service, this can be a relatively light review, sometimes confirmed with a simple will-serve or load letter, and completed in a few weeks. Projects that add significant load or require new service face a more involved engineering review.

Timelines vary widely by utility and region, but a few benchmarks help with planning. A straightforward interconnection that needs no utility-side equipment changes may clear in 4 to 8 weeks. If the utility must upsize a transformer, pull new conductors, or set a new meter, the wait commonly stretches to 4 to 9 months, driven by engineering queues, equipment lead times, and crew scheduling. DC fast chargers, which can demand 50 to 350 kilowatts each, almost always trigger this longer path.

Because these timelines run in parallel with permitting and procurement, boards should start the interconnection conversation as early as the site assessment, not after signing an installation contract. Submitting the application early, even before the final hardware is chosen, keeps your project from stalling while the utility catches up.

Interconnection is not only about getting connected; it also shapes how you pay for electricity afterward. Many commercial and multifamily accounts are billed on rates that include a demand charge, a fee based on your highest spike in power use during the month, measured in dollars per kilowatt. Demand charges commonly run $10 to $25 per kW, and a cluster of chargers firing at once can add hundreds of dollars to a single month's bill.

This is where rate selection and charging schedules pay off. Many utilities offer EV-specific rates or time-of-use pricing that rewards charging overnight, when grid demand is low. Several states have also adopted temporary demand-charge holidays or subscription-style EV rates designed to make multifamily charging affordable. Ask your utility's commercial account team which rate options apply, and confirm that your charging management software can shift load into the cheapest hours.

The encouraging news is that many utilities will pay for a large share of the interconnection and infrastructure work through make-ready programs. In a make-ready arrangement, the utility funds the wiring, panels, and conduit leading up to the charger, and sometimes the charger itself. These programs exist precisely to remove the cost barrier that interconnection upgrades create.

Well-known examples include ConEdison's PowerReady program in New York, PSE&G's EV charging program in New Jersey, and Southern California Edison's Charge Ready and PG&E's EV Charge programs in California. Incentives frequently cover 50 to 100 percent of make-ready costs, with higher percentages for properties in designated disadvantaged or multifamily communities, and some programs add per-port rebates of $1,000 to $4,500 on top.

These programs are typically capped and first-come, first-served, and they usually require pre-approval before any work begins; installing first and applying later can disqualify you. Coordinating the make-ready application with your interconnection request, and stacking it with the federal 30C tax credit, can turn a daunting upgrade bill into a manageable one.

Utility interconnection sounds technical, but a board's role is mostly about sequencing and requesting the right documents at the right time. Pull your building's electrical service rating and 12 months of utility demand data before you talk to installers, so everyone works from real numbers.

Handled in the right order, interconnection becomes a planning milestone rather than a roadblock. Boards that engage their utility early routinely shave months off their schedule and thousands of dollars off their cost, and they avoid the unhappy surprise of a stalled project waiting on a transformer.