Time-of-use rates and demand charges for shared apartment EV charging

A tariff can make the timing of charging financially relevant, but there is no single apartment EV rate for the United States, the United Kingdom or Canada. The applicable answer depends on the utility account, meter, service class, tariff and actual load pattern. Check the building’s bill and tariff before buying controls or promising residents a saving.

Separate the parts of the bill

• Energy charge is commonly tied to the amount of electricity used, measured in kilowatt-hours (kWh). The rate may be flat or vary by time, season or another tariff rule.
• Time-of-use (TOU) pricing sets different energy prices for defined periods. A lower overnight price may help only if the building can shift charging into that window without undermining residents’ departure needs.
• Demand charge is a tariff component based on measured power demand, typically expressed in kilowatts (kW). The utility defines how demand is measured and billed. It may apply to a customer’s peak during a billing period or to another tariff-defined measure; do not assume one interval or calculation.
• Fixed or service charges can remain even when the building shifts energy use.
• Resident charging price is a separate operating and billing decision. It may not equal the utility’s marginal energy cost. Metering, agreements, tax treatment and local rules can affect how a building allocates costs.

A building may have both TOU prices and a demand charge. Moving charging to a lower-price period can change the energy component while leaving a building peak untouched—or create a new peak if many chargers start together. Only the actual account and tariff can show which effect matters.

Use the meter that the tariff uses

Start with the electricity account that would see the charging load. In a multi-unit building, a charger may be served from a common-area meter, a building meter, a dedicated account or a submetered arrangement. The account that residents see in a charging app may not be the meter the utility uses to calculate a building demand charge.

Ask the utility or energy supplier for:

• the current tariff name and version, customer or service class, and account eligibility;
• the time windows, seasons, holidays and any change or enrollment dates;
• how billing demand is measured, including the interval and any ratchets or coincident-peak rules;
• the meter boundary and which building loads appear on the same bill;
• interval data for the relevant account, if available, and the time zone and interval length used;
• any export, demand-response, smart-meter or managed-charging terms that could affect the account.

A national average price or a tariff from another building is not a substitute. A rate designed for a home, fleet or utility program may not be available to a shared residential account.

Test a real charging scenario

Suppose residents return in the early evening while the building also has other large loads. If many vehicles begin charging at once, they may add to a measured peak. A schedule or control might spread some charging into hours when vehicles are parked and a tariff is cheaper. That only helps if the tariff applies to the account carrying the chargers, the vehicles have enough dwell time, and the control follows the utility’s measurement rules.

Compare at least these cases using local data:

1. Current operation: existing building load and charging schedule.
2. Flexible schedule: charging shifts only when a vehicle can still meet its agreed departure need.
3. Managed control: a system adjusts charging using the actual building or charger measurement and any applicable rate signal.
4. No change: the simplest option may be reasonable when flexible load is small or the tariff gives little reason to shift it.

Keep the analysis transparent. Separate energy charges from demand charges, fixed fees, equipment and installation, network costs, maintenance and any utility incentive. Use the building’s actual interval data and the utility’s published tariff terms. Compare a full billing period, because one attractive off-peak window does not show how the building will perform across seasons or occupancy changes. Ask a qualified energy professional to check the calculation when the account has complex demand or export terms.

Keep savings estimates separate from resident billing

A building’s bill reduction is not automatically the right resident fee. If residents pay by measured kWh, confirm whether the meter and billing method meet local requirements. If the building uses a flat or time-based fee, disclose what it covers and how it relates to actual energy use. This article does not set a billing method; see shared charging operations for the resident-service and billing decision.

Also check who receives a utility reward, who pays for the controls and service, and how the arrangement treats residents who cannot shift their charging. A demand response payment or program incentive is conditional on its current eligibility and terms. It should not be treated as guaranteed income or as proof that residents will receive lower prices.

Local verification: General tariff guidance checked 24 September 2026. Tariff names, prices, demand calculations and program rules change by utility and account. Confirm the current documents with the electricity supplier before making a building decision.

For a broader control plan, read managed EV charging for apartment buildings. For capacity and cost assumptions, continue to building electrical capacity and apartment EV charging costs.