What section III says
Article 32 regulates interconnected self-supply: production intended for on-site own consumption, with the plant connected to the grid. And it establishes that surpluses may be injected without consideration, or sold if three conditions are met.
The first two are the expected ones: holding a valid generation permit and interconnection contract, and selling the surpluses exclusively to the State-owned public company, which has the power to acquire them.
The third is the one that changes the calculation: in the case of being an intermittent generator and injecting energy, having its own backup through Electrical Energy Storage Systems or paying for it to the State-owned public company.
Solar and wind are intermittent by definition. So an interconnected self-supply project that injects surplus has two paths: it installs its own storage, or it pays for the backup.
Why this is not bad news
Because most well-sized projects should not be injecting significant surplus in the first place. A system sized on the load curve produces what the plant consumes; the one that injects too much is almost always the one sized on annual consumption.
And because the storage this requirement forces you to consider is the same storage that already made economic sense: the kind that turns midday generation into peak savings and the kind that shaves billable demand. The rule pushes where the engineering was already pointing.
What does change is the order of the conversation. Storage stops being an optional phase two and enters the evaluation from the start, because it may be a condition for the scheme, not an accessory.
The three questions to answer before sizing
Will you inject? If the system is sized so it never exceeds consumption in any interval, the question becomes theoretical. That is decided with the measured load curve, not with monthly consumption.
Which capacity bracket does it fall in? Below 0.7 MW the plant is an Exempt Generator (Generadora Exenta) and does not require a generation permit; article 32 regulates self-supply, which starts at 0.7 MW. They are different regimes, and it pays to know which one you are in before designing.
How much does each route cost? Own storage is capital; paying for backup is a recurring expense. The comparison is not obvious and depends on the profile, the size of the injection and the consideration the authority determines.
What cannot be stated yet
Article 32 itself refers to the Regulations and to the administrative provisions, and establishes that the National Energy Commission (Comisión Nacional de Energía) must issue the contract models, the calculation methodologies and the criteria and bases for determining and updating the consideration.
That means the what is in the law and the how much is in provisions that have to be read case by case. Anyone who gives you a firm figure today for the cost of that backup, without citing the provision, is estimating.
We prefer to tell you what obligation exists and what the amount depends on, and bring you the number when we can cite where it comes from.
Sources
Electricity Sector Law, DOF March 18, 2025 · Regulations of the Electricity Sector Law, DOF October 3, 2025. Articles 17, 19, 25, 30, 31, 32, 33 and 34.
The text of section III of article 32 is quoted literally above. You can verify it by article number without taking our word for it.
If your self-supply project will inject surplus and the generation is intermittent, backup is not optional: it is own storage or payment to the public company. And the first decision is still whether injecting makes sense.
