From April 2026 the Código de Red lifts the minimum power factor at the connection point from 0.95 lagging to 0.97, tested over 95% of measured time rather than as a monthly average. It reaches load centers connected at high voltage and medium voltage load centers with contracted demand of 1 MW or more, which is most automotive, aerospace and electronics plants in the Bajío and the northern border states.
The same fast-moving loads that fail that test are usually the loads that trip on a sub-second voltage sag. So one budget line answers two problems, and the decision in front of plant management is which asset to buy: another capacitor bank, a dynamic compensator, or storage sized to the cells that stop.
This article sets out what changed in the instrument, what a sag actually costs a line, and how storage compares against the cheaper corrective devices. The starting point is measurement, because power quality in industrial plants is not visible on a monthly bill.
What changed in April 2026
The Código de Red is Resolución RES/550/2021 of the Comisión Reguladora de Energía, published in the Diario Oficial de la Federación on 31 December 2021 and in force from 1 January 2022. It sets the technical criteria a load center must meet at its point of connection, and power factor is one of them.
The resolution requires load centers to hold power factor between 0.95 lagging and 1.00 for 95% of measured operating time. The integrator Tecsa, writing on 30 December 2025, and Quartux, writing on 2 January 2026, both read the same instrument as raising that floor to 0.97 from the tenth year of a load center's operation or from April 2026. AP Automatización described the same change on 3 March 2026.
Two details in that rule carry the risk. The first is scope. It is not every plant above 1 MW. It is load centers at high voltage, plus medium voltage load centers whose contracted demand reaches 1 MW. The second is the test. A compliance-time rule cannot be satisfied by a good monthly average, because a plant can average 0.97 and still sit below it for a fifth of the shift.
Enforcement has also moved. The Ley del Sector Eléctrico, published in the DOF on 18 March 2025, replaced the Ley de la Industria Eléctrica and reorganized electricity regulation under the Comisión Nacional de Energía. On our read, the change of regulator matters less to a plant than the change in the measurement basis.
Grid conditions the plant does not control
SENER published PRODESEN 2024-2038 on 31 May 2024. In its base case, national electricity consumption grows 2.4% a year, from roughly 358,670 GWh in 2024 to 495,781 GWh in 2038. The same document calls for 25,251 MW of capacity additions between 2024 and 2027 and lists 194 CFE Transmisión projects covering 5,719 km-c of lines between 2024 and 2030. IMCO summarized those figures on 6 June 2024.
CENACE manages the gap between demand and available margin with declared operating states. Industry & Energy Magazine described the estado operativo de alerta on 15 October 2025 as a preventive condition in which CENACE dispatches additional thermal generation, reschedules maintenance and reprograms flows before any interruption happens. Alert is not a blackout. It is the system running without the cushion that would otherwise absorb a fault elsewhere.
That is the mechanism behind most sags. A fault on a line far from your fence depresses voltage across a wide area for a few cycles, and protection clears it long before a human notices. Hosting capacity adds a second constraint. Where local distribution capacity is already committed, adding a production line means waiting on a CFE upgrade. Storage behind the meter lets a plant add load without that wait. CFE does not publish a typical upgrade lead time, so we do not quote one.
What a sub-second sag costs a production line
On the engagements Mexico Energy Partners has run, most lost production at Mexican manufacturing sites traces to voltage sags shorter than one second rather than to full outages. To an operator it reads as a light flicker. To a CNC spindle or a robot controller it is a loss of synchronization, and the drive goes to a protective stop to avoid damage.
The restart is where the money goes. Machines are cleared, parts in process are inspected, tools are recalibrated, and the shift plan is rebuilt. On our own client accounting, a single four hour stoppage at a Tier 1 automotive plant costs more than 20,000 dollars in lost labor and scrapped material.
Basis for the 20,000 dollar figure. This is Mexico Energy Partners engagement data, not a public statistic. It is measured, not modeled, and it counts direct labor hours lost during the stop plus material scrapped at standard cost, in US dollars of 2026, at multi-line Tier 1 automotive sites. It does not include contractual late-delivery charges or lost margin on units not built, both of which would raise it. Line rate and shift pattern move the number, so re-run it on your own throughput before using it in a business case.
Avoiding two or three of those restarts a year is worth 40,000 to 60,000 dollars on that same basis. That funds battery storage for industrial plants sized to the cells that trip. It does not fund a plant-scale installation, and any payback claim that reaches the whole plant is missing a variable: installed cost per kWh, which depends on site conditions and belongs in a project quote rather than in an article.
Storage also does not protect anything by default. Ride-through depends on how the load is connected. If the protected cell sits behind a static transfer switch or an islanding-capable inverter, the transfer time is the number that matters, and it has to be shorter than the ride-through setting of the first drive that trips. Ask for that transfer time in milliseconds, in writing, before signing.
Power factor, and what actually corrects it
Capacitor banks correct a steady lagging load. They switch in discrete steps and respond in seconds. On a plant with large motor starts, resistance welding or variable frequency drives, reactive demand moves faster than the bank can follow. That is how a site fails a 95% compliance-time test while its monthly billed power factor looks acceptable, and it is the practical reason to read what the Código de Red requires of load centers before ordering more capacitors.
The money at stake is documented. Schneider Electric's Código de Red question and answer note, published 9 December 2019, sets out two sanction bands. Serious breaches of the quality, reliability, continuity and safety provisions carry 2% to 10% of gross income received in the previous year. Failing the technical requirements themselves carries 50,000 to 200,000 minimum salaries. The 10% figure quoted around the market is the top of the first band, not a standard fine.
Storage is one corrective device among several, and it is not always the cheapest. A static VAR compensator or an active harmonic filter corrects power factor and harmonic distortion in milliseconds and costs less than a battery. A dynamic voltage restorer rides through sags without storing energy for load shifting. A UPS or a flywheel protects a defined load for a defined number of seconds. A battery inverter does power factor correction, sag ride-through and peak shaving from one asset, which is the argument for it, on total installed cost rather than on capability alone.
Frequency, grid-forming inverters and curing processes
Aerospace composite curing and heat treatment depend on tight process control, and a disturbance during a cure cycle can scrap a part with hundreds of hours of value in it. Rooftop solar on its own can introduce that disturbance. Output falls by most of its value within seconds when a cloud passes, and the plant connection absorbs the step.
Grid-following inverters take their voltage and frequency reference from the network, so they cannot hold a reference the network is not providing. Grid-forming inverters establish their own reference and can hold 60 Hz for the loads behind them, an effect usually described as synthetic inertia. For a curing oven or an autoclave the question is narrow and answerable. Ask the supplier for the voltage and frequency tolerance the inverter holds through a transfer, then compare it against the tolerance your process controller needs.
How the three options compare
| Metric | Grid only | Solar without storage | Solar with BESS |
|---|---|---|---|
| Power factor at 0.97 over 95% of time | Depends on capacitor bank speed | Little change | Corrected by the inverter |
| Sub-second sag ride-through | None, drives trip | None | Set by transfer time |
| Modeled cut in billed peak demand, kW | 0% | 15% | 45% |
| Cover across the 24 hour cycle | None | Daylight hours only | 24 hours |
| Modeled cut in annual electricity spend, MXN | 0% | 20% | 40% to 55% |
Basis for the table. The percentages are modeled outputs from Mexico Energy Partners sizing studies for medium voltage industrial sites on the GDMTH tariff. They are not measured averages across a published population. Peak demand reduction is the modeled change in billed maximum demand in kW over a twelve month simulation run against each site's own interval data. The 40% to 55% range is the modeled change in the annual electricity bill in MXN and it combines the energy charge, the billed demand charge and avoided power factor penalties, so it is not comparable to an energy-only saving. The 20% figure for solar without storage assumes an array sized to daytime load at the same sites. The first two rows are rankings, not measurements.
What to do in the next two quarters
Start with measurement rather than procurement. A monthly CFE bill cannot size storage and cannot prove compliance under a time-based test. A recorder on the incoming feeder, logging for at least 30 days, produces sag depth and duration counts and a power factor record you can hold against the rule.
Then isolate. Backing up a five hectare plant for a full day is rarely worth its cost. Identify the cells whose stoppage costs the most, size storage to those, and leave the rest on the grid. That discipline is what keeps the capital number defensible in front of a board.
- Pull twelve months of interval data and test power factor against the 95% compliance-time rule, not against the average printed on the bill.
- Record the ride-through setting of every drive that has tripped, so the transfer time you specify is shorter than the setting that fails first.
- Price a static VAR compensator and an active harmonic filter alongside storage, so the battery has to win on installed cost rather than by assumption.
Energy-as-a-Service structures remove the upfront capital and shift the equipment onto a provider's balance sheet, with the plant paying a monthly fee. On the structures we have reviewed, three terms decide whether they are worth it: who carries the Código de Red compliance obligation, what happens to the fee if CFE changes the tariff, and what the buyout price is at each anniversary.
Measure the sags before you size the battery
Mexico Energy Partners installs a power quality recorder on the incoming feeder for 30 days. We log sag depth and duration against the trip thresholds of the drives that stop your lines. You get back a sizing memo for critical load isolation and a power factor record tested against the 95% compliance-time rule.
To start, send twelve months of CFE bills, the single line diagram, the list of loads that trip and the ride-through settings of those drives. We confirm scope and recorder placement before any site visit. The memo states what was measured and what was modeled, and it does not put a saving figure on the table before the logging period ends.
Sources
- Comisión Reguladora de Energía, Resolución RES/550/2021, Código de Red, Diario Oficial de la Federación, 31 December 2021, in force 1 January 2022. Power factor criterion for load centers.
- Tecsa, "Lo que debes saber para cumplir con el Código de Red 2026", 30 December 2025. Scope of the 0.97 requirement and the April 2026 date.
- Quartux, "¿Qué es el Código de Red 2.0?", 2 January 2026. Compliance-time test and the 1 MW threshold.
- AP Automatización y Control Eléctrico, "Código de Red 2.0 en el 2026, FP de 0.97", 3 March 2026. Corroboration of the 0.97 value.
- Schneider Electric, "Código de Red: preguntas frecuentes", 9 December 2019. Sanction bands for breaches of the quality and reliability provisions.
- Ley del Sector Eléctrico, Diario Oficial de la Federación, 18 March 2025. Reorganization of electricity regulation under the Comisión Nacional de Energía.
- SENER, PRODESEN 2024-2038, 31 May 2024, with IMCO's summary of 6 June 2024. Demand growth, capacity additions and transmission program.
- Industry & Energy Magazine, "CENACE en Estado Operativo de Alerta", 15 October 2025. Definition and effect of the alert operating state.