ForgeAsset / Utilities / NorthWestern Energy

NorthWestern Energy GSEDS-1 — EV fast-charging electricity cost

NorthWestern Energy GSEDS-1 is the filed rate schedule ForgeAsset models for DC fast-charging sites in NorthWestern Energy territory in Montana. Energy prices at 10.4¢/kWh flat; the demand side bills $14.36/kW of monthly peak. For one reference Supercharger site held constant across the whole library, that works out to 41.8¢/kWh per dispensed kWh — rank 51 of 86 filed tariffs (1 = least expensive).

Modeled rates

Flat bundled rate: NorthWestern's delivery, supply, and rider components summed from the filed Total Rate sheets, which already include Montana's utility taxes. Demand is billed per kW of the month's 15-minute peak with no ratchet, no time window, and no seasonal variation. Montana levies no general sales tax. The 3¢/kWh public-charging tax is billed by the utility on a dedicated meter and is carried on the tax-profile side, not in this rate. The supply deferred component trues up quarterly.

The filed rate book for this territory records no EV-specific commercial rate, so the modeled cost is the standard schedule. Demand follows the model's conservative convention — 150 kW per stall billed every month, the worst-case coincident peak — so a site whose metered peak runs below that would see a lower demand line.

Source: NorthWestern Energy filed rate schedule. Rates are digit-verified against the utility's own filed sheets and update within two weeks of any revision; derivations are on the methodology page.

What the reference site pays here

Reference site: 8 Tesla V4 stalls at 235 kWh/stall/day (57,183 kWh dispensed per month), a 150kW per-stall demand assumption, the model's default time-of-use mix, and a 12% loss gross-up — identical to the full utility ranking, where this tariff sits at position 51 of 86.

The rest of the Montana picture

The tariff is one layer. State taxes, incentives, clean-fuels programs, and the charging market shape the remainder — Tesla Supercharger ROI in Montana covers them, and the US Supercharger Economics Map shows every US Supercharger over utility territories colored by this same effective-cost derivation.

NorthWestern Energy GSEDS-1 — questions

What does NorthWestern Energy charge for energy on GSEDS-1?

The modeled rates are 10.4¢/kWh flat. At the model's default time-of-use mix (30% peak, 45% off-peak, 25% super-off-peak) that blends to 10.4¢/kWh.

Does GSEDS-1 carry a demand charge?

Yes: $14.36/kW of monthly peak. For a reference 8-stall site at 150 kW per stall that comes to about $17,228 per month.

What does electricity cost per kWh dispensed on this tariff?

For the reference site — 8 Tesla V4 stalls dispensing 235 kWh per stall per day, with a 12% loss gross-up — the all-in utility cost works out to 41.8¢/kWh per dispensed kWh, rank 51 of 86 tariffs in the library (1 = least expensive).

ForgeAsset is software, not investment, tax, or legal advice — outputs are model estimates from your inputs, not guarantees. Rates current as of research; verify current terms with the utility's filed schedule before committing capital.