1. What is the GDMTH tariff?
GDMTH is CFE’s tariff for large consumers connected at medium voltage. It has three time bands with different energy prices (base, intermediate and peak) and charges for the demand your plant registers.
2. Base, intermediate and peak bands: three prices for energy
| Band | When | Charge (Norte, July 2026) |
|---|---|---|
| Base | Early morning, the cheapest band | MXN 0.9908/kWh |
| Intermediate | Most of the day | MXN 1.5710/kWh |
| Peak | The most expensive band: 18:00 to 22:00 in winter, in the Norte division | MXN 1.8372/kWh, 85% more than base |
3. Billable demand is set by your peak-hour maximum
It is the demand in kW that CFE charges you. It is driven by your maximum demand during peak hours: the higher your peak in that band, the more you pay.
4. How are the capacity and distribution charges calculated?
These are the two demand charges on your bill: capacity and distribution.
| Charge | How it is calculated | Norte, July 2026 |
|---|---|---|
| Capacity | On your billable demand | MXN 386.37/kW |
| Distribution | On the maximum measured demand, with a cap | MXN 72.92/kW |
5. Power factor: a surcharge or a credit
With less than 1 MW of contracted demand, CFE adds a surcharge if your power factor is below 90% and gives you a credit if it is above. With 1 MW or more, the threshold is 97%. Separately, since April 2026 the Grid Code has required 97% (0.97) from medium-voltage plants of 1 MW or more.
6. Which charges does a BESS lower?
- Peak energy: the BESS discharges in that band and your plant draws from the BESS. This is the main source of savings.
- Capacity: by cutting peak demand, billable demand falls and this charge with it.
- Distribution: falls as the maximum demand registered by the meter falls.
- Power factor: the inverter compensates reactive power continuously. A surcharge shrinks or turns into a credit, and an existing credit grows.
- Base energy: rises slightly, because the BESS charges in that band, when energy costs less.
Use the Ollin Simulator to estimate what a BESS would save your plant.
The simulator asks you to create an account with your company email. Actual savings are measured every month once the system is running at your plant.
Sources
- CFE, GDMTH tariff, Norte division, July 2026 (charges published by CFE).
- CRE, Grid Code, RES/550/2021 (DOF, December 31, 2021).