The Rate Wall: How Utility Demand Charges Decide Whether a Fast Charger Survives
Electric-vehicle fast chargers are usually judged on how busy they get. But whether a charger can pay for itself is set just as much by which utility it plugs into — and that varies enormously across the country. Pricing 241 U.S. commercial electricity tariffs on the rate a DC fast charger actually pays, this study finds that a fee most people never think about — the demand charge — is what pushes many chargers underwater, no matter how good the location.
Key findings
- At today's real-world utilization (about 16% of the time in use), the typical territory's electricity costs about $0.35/kWh — but in 27% of territories it costs more than the ~$0.49 drivers pay, so the operator loses money on electricity alone, before any other cost. In 14%, it tops $0.60.
- The cause is the demand charge, not the price of power. Removing just the demand charge from a conventional rate cuts the cost by a median of about $0.30/kWh — the same electricity, priced completely differently by the shape of the tariff.
- Under a full business case at average traffic, only about a third of territories break even on cheap financing, and roughly a fifth at a realistic cost of capital.
- Subsidies barely move it. Tripling a capital grant gets you to about half of territories at best. Moving a territory onto a no-demand EV rate makes close to nine in ten viable — so the most powerful lever is rate design, not more hardware money.
- A handful of places (chiefly high-cost California municipal utilities) stay underwater because power itself is expensive there; no tariff fix closes that gap.
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The Rate Wall: How Utility Demand Charges Determine the Financial Viability of DC Fast Charging
A demand-aware pricing analysis of 241 U.S. commercial electricity tariffs — the actual rates a DC fast-charging site is billed on — quantifying how utility demand charges, not the price of energy, decide whether a charger can pay for itself.
Reproducibility
Code and a public data sample (39 encoded rate schedules) are openly available and reproduce the paper's results:
GitHub: rightsitera-arch/rate-wall-reproducibility
Archived at Zenodo (DOI: 10.5281/zenodo.21667465) — activates on release
License: code MIT; data sample CC BY 4.0
How to cite
Lightfoot, J. (2026). The Rate Wall: How Utility Demand Charges Determine the Financial Viability of DC Fast Charging (RightSite Working Paper). https://github.com/rightsitera-arch/rate-wall-reproducibility
Transparency
The author operates RightSite, which uses the tariff library and pricing method described here; this competing interest is disclosed in full in the paper. The full 241-schedule library is proprietary, but every underlying tariff is a public utility document, and the released engine plus sample let anyone reproduce the method.