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Supercharger demand charges by utility and state
The demand charge is often the largest line on a Supercharger's utility bill. This tool shows the filed demand-charge and time-of-use energy structure for 18 utility tariffs across 12 states, and an illustrative monthly figure for a chosen stall count. It reports the numbers from each utility's own filed sheets; it renders no verdict.
- Demand charge
- $95.56/mo per 50 kW block
- Energy
- 13.3¢/kWh–37.0¢/kWh by time of day
Illustrative demand charge · 8 stalls
$2,293 / month
$27,521 / year
Figure uses a default per-stall demand of 150 kW (a Tesla V4 stall) applied to the filed subscription-block structure. Billed demand depends on stall power, simultaneity, and metering; the full report models it for a specific site.
Filed rate — source. Demand subscription in 50 kW blocks. Rates are the model's PG&E calibration.
How a Supercharger demand charge is set
Two tariff structures appear across the library. A subscription-block tariff charges a fixed amount per block of subscribed capacity, rounded up to the next whole block. A per-kW tariff multiplies the billed monthly peak in kilowatts by a dollar-per-kW rate. Some EV and delivery classes carry no separable demand charge at all, folding capacity cost into the energy rate. The estimate above applies a default per-stall demand of 150 kW for a Tesla V4 stall to whichever structure the selected tariff files.
Demand charge across 18 tariffs
| State | Utility & tariff | Demand | Energy |
|---|---|---|---|
| Arizona | APS E-32 L | $22.19/kW of monthly peak | 6.9¢/kWh flat |
| Arizona | TEP TILGS | $23.14/kW of monthly peak | 7.6¢/kWh flat |
| California | PG&E BEV-2-S | $95.56/mo per 50 kW block | 13.3¢/kWh–37.0¢/kWh by time of day |
| California | SDG&E EV-HP | $127.71/mo per 25 kW block | 14.8¢/kWh–33.6¢/kWh by time of day |
| California | SCE TOU-EV-9 | none | 14.4¢/kWh–46.2¢/kWh by time of day |
| Florida | FPL GSLD-1 | $19.38/kW of monthly peak | 6.2¢/kWh flat |
| Georgia | Georgia Power TOU-EVC-2 | $5.10/kW of monthly peak | 9.8¢/kWh–15.7¢/kWh by time of day |
| Illinois | ComEd Watt-Hour EV class | none (energy-only) | 14.1¢/kWh flat |
| Michigan | DTE Electric D3 | none (energy-only) | 18.3¢/kWh flat |
| Michigan | Consumers Energy GP | none (energy-only) | 13.4¢/kWh flat |
| North Carolina | Duke Energy Carolinas LGS | $5.16/kW of monthly peak | 10.2¢/kWh flat |
| North Carolina | Duke Energy Progress LGS | $19.81/kW of monthly peak | 6.5¢/kWh flat |
| Oregon | Portland General Schedule 38 | none (energy-only) | 20.3¢/kWh–23.3¢/kWh by time of day |
| Pennsylvania | PPL GS-3 | $5.47/kW of monthly peak | 13.8¢/kWh flat |
| Tennessee | Nashville Electric EVC | none (energy-only) | 26.3¢/kWh flat |
| Tennessee | MLGW GSA Part 3 | $18.47/kW of monthly peak | 9.7¢/kWh flat |
| Texas | Austin Energy ≥300 kW | $17.63/kW of monthly peak | 7.3¢/kWh flat |
| Virginia | Dominion GS-3 EV | none (energy-only) | 14.3¢/kWh flat |
Rates are digit-verified against each utility's own filed sheets and update within two weeks of any revision. Full derivations are on the methodology page.
Demand charges — questions
- What is a demand charge on an EV charging tariff?
- A demand charge bills for the highest rate of power draw in a period, separate from the energy charge that bills total kilowatt-hours. On a Supercharger it is often the largest single line on the utility bill because the site draws a large peak even when total energy is modest.
- How is a Supercharger demand charge calculated?
- It follows the tariff's structure. A subscription-block tariff charges a fixed amount per block of subscribed capacity, rounded up. A per-kW tariff multiplies the billed monthly peak in kilowatts by a dollar-per-kW rate. This tool applies both structures using a default per-stall demand for a Tesla V4 stall.
- Why do some tariffs show no demand charge?
- Several utilities file EV or delivery classes with no separable demand charge — the cost of capacity is folded into the energy rate instead. Those rows show a structural zero, which is a real feature of the filed tariff rather than a gap in the data.
The demand charge is one line of a full model. Run a Tesla V4 Supercharger scenario — payback, NPV, IRR, and a 15-year cash flow from your own inputs.
Run a scenarioForgeAsset is software, not investment, tax, or legal advice — outputs are model estimates from your inputs, not guarantees. Rates are current as of research; verify current terms with each utility's filed tariff before committing capital.