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Utility scale
Published
September 29, 2026
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7 minutes
Who it is for
Maintenance leads, plant engineering and management

Interconnection studies: what really decides whether the project exists

In a generation project of a certain scale, your own engineering is rarely the problem. The problem is the point where your facility meets the grid, and you do not decide that: a study does.

Engineer inspects medium-voltage switchgear with a tablet.
The studies decide the works at the point of connection before you buy equipment.

What an interconnection study really asks

It does not ask whether your project is good. It asks whether the grid can take it at that point, at that capacity, without degrading operation for everyone else connected to the same circuit.

That question yields the four answers that define the project: the capacity that can actually be interconnected, the works needed to achieve it, who pays for them, and on what timeline.

And here is the uncomfortable part: all four can differ from what your project assumed. A study can return a lower capacity than requested, or make interconnection conditional on works whose cost changes the business case.

Why the result arrives late in most projects

Because the study is requested after the design is done, and often after quoting and presenting to the committee. When the result constrains the capacity, the sizing, the proposal and the payback have to be redone — with the project already approved internally on other figures.

The order that avoids this is the reverse: first find out what is available at the point of connection and what has recently been interconnected on that circuit, and size within that frame. It does not eliminate the study, but it turns its result into a confirmation instead of a surprise.

It is the same logic we apply to everything else: measure before proposing. Here what gets measured is the grid, not the plant.

Figure 1
Asking about the grid before designing eliminates rework
USUAL SEQUENCE Design Quote Approve Request study Redo Rework: sizing, proposal and payback with the project already approved on other figures RECOMMENDED SEQUENCE Check availability Size Request study Confirm The result arrives as a confirmation, not a surprise.
The study is done in both sequences; what changes is whether its result arrives before or after sizing.

What the study will ask you for, and what you should have beforehand

The requested capacity and point of connection, with the single-line diagram of how it will connect. If your facility does not have up-to-date drawings, this is the moment that becomes a problem with a deadline.

The technical characteristics of the generation: type, capacity, behavior during voltage sags, regulation capability, and —for intermittent generation— the backup scheme.

The expected operating profile: how much it will generate, at what hours, and whether it will export. It is not an administrative detail: it changes the analysis.

The protection and metering scheme proposed at the point of interconnection.

Almost all of that comes from the site survey and metering. When a project reaches the study without those inputs, the delay is not caused by the authority.

What the study can return, and what to do with each result

Approved capacity equal to the requested capacity, with no major works. The best case, and the least common in areas with a saturated grid. You move forward.

Lower approved capacity. You have to decide: size to the approved limit, or reconsider the point of connection. A project that only works at the original capacity was not a robust project.

Interconnection conditional on works. Here the question is how much they cost, who pays for them and on what timeline they are carried out. Those three answers can make a project that is viable at the generation level unviable at the connection level.

Long timeline. It is the most frequent result in Mexico, and the one that opens the most useful conversation: what can be done inside the fence line while that moves forward. Storage to defer the load increase, contracted demand adjustment, power factor correction and backup — none of that goes through interconnection.

Figure 2
Four possible results, four different decisions
Study result Capacity equal to the request, no works Lower approved capacity Interconnection conditional on works Long timeline THE MOST FREQUENT Move forward The best case and the least common Size to the approved limit or reconsider the point of connection Evaluate the works Cost, who pays, what timeline Act inside the fence line Storage, contracted demand, power factor and backup
The long-timeline result is the most frequent in Mexico and opens the most useful conversation: what can be solved without going through interconnection.

Where we come in

In the site survey and metering that feed the application, in protection coordination at the point of interconnection, and in the electrical works inside your facility. That part is ours at any project scale.

And in the "meanwhile" conversation, which is where the most value lies when the interconnection timeline does not fit the production plan.

Development of a generation project that requires a permit is handled by GIS Power, part of the same group, which has the built track record at that scale. We do the assessment and the introduction together.

Sources

Electricity Sector Law (Ley del Sector Eléctrico), DOF March 18, 2025 · Regulations of the Electricity Sector Law (Reglamento de la Ley del Sector Eléctrico), DOF October 3, 2025. Articles 18, 19, 30, 32 and 151. The Regulations of the Electricity Sector Law govern the interconnection and connection procedures.

The specific requirements of each study and its timelines are set out in the Regulations and in the applicable administrative provisions, and are read case by case. This article describes what a study decides and what inputs it needs, not timelines or fees.

The question that organizes the project

How much capacity is available at that point of connection, and by when, in writing? Finding out before sizing turns the study into a confirmation. Finding out afterward turns it into rework.

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