Where EV adoption lands on an industrial site
The number that decides whether vehicle electrification helps or hurts a Mexican plant is the kilowatt reading on its own meter, not the vehicle count. Fleet chargers, employee chargers and visitor chargers all add coincident demand to a site already billed for capacity as well as for energy. Charging is a demand-charge problem before it is a fuel-cost problem. A plant director, energy manager or CFO who treats a charging installation as a vehicle procurement decision rather than an electrical one finds out the difference on the following month's CFE bill. What follows is what to check before the electrical scope is fixed.
The demand is arriving from the vehicle side. Stellantis is weighing a multibillion-dollar retooling of its Saltillo, Coahuila plant to build hybrid and electric vehicles, with its Toluca and Sonora sites also under review (Transport Topics, 12 August 2022). Frost & Sullivan projects 200,000 electric and hybrid vehicle sales in Mexico by 2030, growing at roughly 25% a year and accounting for about two thirds of a Latin American total of 300,000 units (Mexico Business News, 14 July 2022). Neither figure tells a facility what its own bill will do.
Public infrastructure will not absorb the load. CFE announced MXN 60 million in 2018 for the installation and strengthening of 100 charging points nationwide, alongside SENER, as stated by its then director general Jaime Hernández (Forbes México, 7 May 2018). CFE is the state utility and a market participant, not the regulator. Tariffs and permits sit with the Comisión Reguladora de Energía (CRE), which approves the schedules that charging is billed under, while the Centro Nacional de Control de Energía (CENACE) dispatches the system. Public spending at that scale funds a demonstration network. Industrial charging will be built and paid for on private sites.
What charging does to a demand profile
Read the tariff class off a mid-size Mexican plant's CFE bill and it is usually GDMTH, the medium-tension large-demand class for users at 100 kW of demand or more, taking supply between roughly 1 kV and 35 kV. Larger single-site loads sit on DIST at subtransmission voltage or DIT at transmission voltage. All three bill time of use across the daily base, intermedio and punta periods. All three also carry a capacity component tied to measured demand rather than to consumption (CFE tariff schedules approved by CRE, in force through 2022).
That second charge is what makes charging expensive in a way diesel never was. A DC fast charger pulls close to its rated power for as long as a vehicle is plugged in. It does not care what else the plant is running. An illustrative case makes the arithmetic visible. Eight 50 kW DC units installed at a distribution center represent 400 kW of connected charging capacity. If drivers plug in at shift change and four units run at once, the site adds roughly 200 kW of coincident demand. If that coincidence falls inside the punta window, the plant pays a punta capacity charge set by that single monthly peak, for the whole month, whether or not the chargers ever run in punta again. One shift change writes the number. The bill carries it for another thirty days. This calculation is illustrative and depends entirely on the site's own tariff, contracted demand and interval data.
Take one distinction into the budget discussion. There is load you control and load you do not. Fleet charging is schedulable. Yard tractors, delivery vans and shuttle buses return to a known place at a known hour and can be sequenced into the base period overnight, where both the energy and the capacity exposure are cheapest. Workplace and visitor charging is not schedulable. Employees arrive in the morning and plug in at once, which is precisely when many plants are already climbing toward their monthly peak. A facility that puts both on the same panel without load management has bought the second profile at the first profile's price.
What to verify before the first charger goes in
The assessment work is unglamorous and it decides the outcome. Before signing for chargers, a facilities or energy manager should have the following in hand:
- Twelve months of CFE billing, showing measured demand by period and the resulting capacity charges, not just total consumption.
- Interval data at the main meter, so the existing peak's timing and duration are known rather than assumed.
- The site's contracted demand and the headroom left in the service transformer and main switchgear.
- A current single-line diagram and the available spare capacity on the panels the chargers would feed.
- The daily boundaries of the base, intermedio and punta periods for the site's tariff and region, which differ by season.
- Whether the added capacity triggers a service modification with CFE Distribución, and the lead time that carries.
- Whether the charger hardware supports power sharing and scheduling, or whether load management has to be added separately.
We would expect load management software and a scheduling policy to cost less than the transformer upgrade they avoid, and far less than a year of higher capacity charges. Price that trade-off before the electrical scope is fixed.
Onsite generation helps with energy, and not much with the peak
Solar is the reflex answer and it is only a partial one. Under the distributed generation regime, a plant may interconnect generating capacity below 0.5 MW to the distribution network under the SENER Manual de Interconexión (DOF, 15 December 2016) and CRE Resolución RES/142/2017 (DOF, 7 March 2017). The limit applies to generating capacity in MW, not to the facility's load and not to DC panel rating in kWp. A plant drawing 4 MW can still hold a distributed generation contract, provided the array itself stays under the threshold.
The regime matters for what it does not offset. Under medición neta, surplus generation accrues as energy credits carried against future consumption for up to twelve months (CRE RES/142/2017). Credits reduce energy charges. They do not reduce a capacity charge created by a demand peak at 19:00, when the array is producing nothing. Sites that want generation to shave the peak itself are looking at storage paired with the array, which is a separate investment case with its own regulatory questions, since CRE had issued no general provisions defining how storage participates in the wholesale market as of 2022. Facilities above the 0.5 MW threshold, or with 1 MW or more of demand, should also be running the qualified supply comparison in parallel, because the supply contract and the charging plan move the same bill.
The manufacturing build-out is a load forecast in disguise
For suppliers in the automotive chain, the Saltillo decision carries a second implication. A Stellantis spokesperson, Shawn Morgan, told Transport Topics on 12 August 2022 that the review was routine capital allocation: "We invest regularly in plants all around the world to upgrade in terms of process, vehicle production, or adapt to electrification as part of our $35 billion investment in electrification and software." Retooling a truck plant for electric drive changes what it buys, and it changes the electrical intensity of the tier-one and tier-two plants around it. Battery pack assembly, e-motor winding and power electronics testing are more electricity-intensive per unit of output than stamping and trim.
Domestic assembly is at a much smaller scale. Zacua, founded in 2017 and building at a plant in Puebla since 2018, listed its two models, the MX2 and MX3, at MXN 599,990 in February 2022 (El Heraldo Binario, 9 February 2022). The volumes are small and they do not change a supplier's load forecast. The Saltillo decision would.
A supplier in Coahuila, Nuevo León or the Bajío should ask what a customer's electrification program does to its own connected load over the next five years, then raise it with CFE Distribución before the capacity is needed rather than after a contract is signed. Interconnection and service upgrades are scheduled by the utility, not by the customer, and a plan for onsite generation takes months to permit and build.
Review what charging would do to your demand charges
Mexico Energy Partners can model the effect of fleet and workplace charging on a facility's measured demand and CFE bill before the electrical scope is set, and compare load management, scheduling and onsite generation against the cost of a service upgrade. The initial review needs twelve months of CFE billing, interval data at the main meter, a current single-line diagram and the number and rating of chargers under consideration.