CFE and the DAC tariff: why your Mexican electric bill can explode

Newcomers to Mexico are usually delighted by their first electric bill from CFE (Comisión Federal de Electricidad, the national utility). A modest inland home might pay MXN $200–$500 every two months, absurdly cheap by U.S. or Canadian standards. Then summer arrives, the air conditioning runs, and one day a bill lands for MXN $6,000, $9,000, even $14,000 for a single two-month period. Nothing broke. You simply crossed an invisible line and lost the government subsidy that made electricity cheap. That line is called the DAC tariff, and understanding it is the difference between a home that costs almost nothing to run and one that quietly bleeds money.

How Mexico’s residential subsidy works

Residential electricity in Mexico is heavily subsidized, but only up to a point. Most homes sit on Tarifa 1 or one of its hot-climate variants (1A through 1F), where the government absorbs a large share of the true cost. The hotter your region’s officially recognized climate, the more subsidized kilowatt-hours you get before prices climb.

Billing is bimonthly (every two months) and tiered:

• Básico: the cheapest block, roughly MXN $0.90–$1.05 per kWh
• Intermedio: a middle block, roughly MXN $1.10–$1.70 per kWh
• Excedente: everything above, which can run MXN $2.90–$3.50 per kWh and up

So far, so manageable. The trap is not these tiers. The trap is falling off them entirely.

The DAC tariff: losing the subsidy

DAC stands for Tarifa de Alto Consumo (High Consumption Tariff). CFE tracks your rolling average consumption over the past 12 months. If that average exceeds your region’s monthly threshold, you are reclassified as DAC and the subsidy disappears completely.

Under DAC there is no cheap básico block. Every kilowatt-hour is billed at the unsubsidized rate, commonly MXN $5.50–$7.00 per kWh plus a fixed monthly service charge, roughly three to five times the subsidized price. The jump is brutal and immediate.

Regional thresholds (average monthly kWh; verify your exact tariff on your bill) run roughly:

• Temperate/inland (Tarifa 1): about 250 kWh/month average
• Warm zones (1C / 1D): about 850–2,000 kWh/month
• Hot coastal zones (1E / 1F): about 2,500–4,000 kWh/month

Coastal buyers assume the high threshold protects them. It doesn’t, because coastal homes run air conditioning constantly.

Why coastal and AC-heavy homes get hit

Air conditioning is by far the biggest driver. A single mid-size mini-split running most of the day pulls roughly 1.0–1.5 kWh per hour. Run it 10 hours a day and that one unit is 300–450 kWh a month. A three-bedroom coastal home with three units running through a humid summer can burn 1,500–2,500 kWh a month without anyone thinking they’re being wasteful.

Because DAC is based on a 12-month rolling average, one brutal summer can drag you into DAC and keep you there deep into winter. Getting out of DAC requires holding your average back under the threshold for several consecutive billing periods, so the penalty has a long tail.

Watch these energy hogs:

• Air conditioning: the number-one cause, especially old non-inverter units
• Electric water heating and pool pumps: pumps can run 6–8 hours a day
• Old refrigerators and chest freezers: a 15-year-old fridge can double a modern one’s draw
• A poorly insulated home: single-pane glass and dark roofs turn AC into a losing battle

What this means for a vacation rental

For a short-term rental, DAC is a silent yield-killer. Guests set the AC to 18°C, leave it running with the doors open, and never see the bill, you do. A rental that “should” cost MXN $1,500 in electricity per period can easily hit MXN $8,000–$12,000 in DAC during high season, and that is pure margin gone. Many owners cap AC behavior with smart thermostats or simply price electricity risk into the nightly rate. If you underwrite a rental’s returns without modeling DAC-level power in summer, your real yield will disappoint.

How to keep control of your bill

• Read your actual tariff: it is printed on the bill (Tarifa 1, 1C, 1F, or the dreaded DAC). Know your regional threshold.
• Go inverter: modern inverter mini-splits use 30–50% less power than old on/off units; replacing units at MXN $8,000–$18,000 each often pays back in a season on the coast
• Insulate the envelope: reflective roof coating, thermal curtains and sealing gaps cut AC load cheaply
• Kill phantom pool and pump loads: run pool pumps on a timer, off-peak, fewer hours
• Consider solar: a residential grid-tied solar system under net metering (medición neta) can zero out a bill and, critically, keep your consumption average low enough to stay off DAC. A typical 3–5 kW system runs MXN $60,000–$140,000 installed, with payback often in 4–7 years, faster if you’d otherwise be in DAC
• Watch the meter, not just the bill: check your CFE app mid-cycle so a bad month doesn’t surprise you

A word on solar and DAC: if you install solar, keep an eye on how CFE nets your generation. Done right, net metering both slashes cost and protects your subsidy. Done carelessly, an oversized system with poor billing setup can leave surplus credits stranded.

The bottom line

CFE electricity is a genuine bargain until the moment it isn’t. The whole game is staying below your regional consumption threshold so you keep the subsidy and never touch DAC.

Cost checklist:

• Subsidized bill (inland, modest use): MXN $200–$1,000 per 2 months
• Subsidized coastal home with disciplined AC: MXN $1,500–$4,000 per 2 months
• DAC bill on a busy coastal/rental home: MXN $6,000–$14,000+ per 2 months
• Inverter AC swap: MXN $8,000–$18,000 per unit
• Grid-tied solar (3–5 kW): MXN $60,000–$140,000, payback 4–7 years

Know your tariff, run inverter units, cap the pool pump, and treat crossing into DAC as the expensive mistake it is. On the coast especially, solar plus efficient AC isn’t a green luxury, it’s the difference between a home that costs pennies to run and one that eats your rental income.