When a Qualified Supplier presents you with an offer, the number that shines is the savings: "15% to 30% less than CFE." It is a good headline, but it is only one side of the coin. The other side is the cost of participating in the MEM that almost never appears on that first slide: the guarantees you must post with CENACE, the recurring market operating fees, and the management and administration overhead that comes with living inside the Wholesale Electricity Market (MEM). That gross savings is not what reaches your cash flow; what reaches it is the net savings, after deducting everything above.
This article is the breakdown that's missing before you sign. It is not meant to scare you: for most industrial profiles with sufficient volume, the savings still win comfortably. It is so you know exactly what you are buying, where each peso hides, and why the only number that matters is the projected net over time. If you want that number for your plant, the 24-month MEM ROI calculator builds it from your real bill.
How much does participating in the MEM really cost?
Participating in the MEM costs, in addition to the savings you capture on the energy price, a set of entry and operating costs that change the real ROI. There is a one-time cost to register and get in, there are financial guarantees that tie up capital, and there are recurring fees for operating inside the market and for using the transmission and distribution grids. Gross savings live in the energy price; these costs live in everything that surrounds that price.
The reason they are called "hidden" is not that they are deliberately concealed, but that the sales conversation leaves them out so the savings look bigger. When you put them on the table, the calculation shifts from "how much do I save?" to "how much is left after operating?" That is exactly the difference between optimistic gross savings and an honest ROI, and it is the same logic that applies to real savings as a Qualified User. If you are still not clear on how the market works in general, it is worth first reading the MEM explained for non-experts.
What guarantees does CENACE require?
CENACE, as the market operator, requires performance guarantees that back your payment obligations inside the Wholesale Electricity Market. In practice these are deposits or financial instruments (letters of credit, surety bonds, or cash collateral) that cover the risk of a participant failing to settle what it consumed or what it owes the market. It is not an expense that's lost, but it is capital that gets tied up or that carries a financing cost while you participate.
The amount is neither fixed nor public as a single figure: it depends on your consumption volume, your profile, and the market rules in force, and it is recalculated over time. That is why we don't give you an exact number here, because any closed figure would be invented. The right way to understand it is as a concept: the larger and more volatile your consumption, the larger the guarantee the operator will ask you to back.
The impact of guarantees on your ROI takes two forms, and it's worth distinguishing them:
| Form of the cost | What it means | Effect on cash flow |
|---|---|---|
| Capital tie-up | Your own money posted as collateral that is no longer available | Opportunity cost: that capital generates no return elsewhere |
| Financing cost of the instrument | The fee on a letter of credit or surety bond a bank issues on your behalf | Direct recurring expense subtracted from the savings |
An oversized guarantee erodes net cash flow without you noticing it in the savings headline. Sizing it correctly —neither too much, which freezes capital, nor too little, which exposes you to margin calls— is part of the management work, not a minor formality.
What recurring fees and charges are there?
Inside the MEM you pay recurring fees for three different things: the operation of the market itself, the ancillary services that keep the grid stable, and the use of the transmission and distribution grids so the energy reaches your plant. These charges exist no matter which supplier you buy from; they are the toll for operating inside the national electric system, not a supplier markup.
The most expensive confusion is believing that the energy price is the total price. The energy price (the component you negotiate and where the savings are) is only one part of your final bill. On top of it ride the regulated grid and operation charges, which are practically the same for everyone and which the supplier does not control. This table separates the cost types so you can see where you have leverage and where you don't.
| Cost type | What it covers | Negotiable? |
|---|---|---|
| Energy (LMP by node) | The kWh you consume, valued at the Local Marginal Price of your load zone | Yes, via contract and spread with the supplier |
| Market operation | The service CENACE provides to operate and settle the market | No, it is a regulated fee |
| Ancillary services | Reserves and control that keep the system stable (frequency, voltage) | No, it is prorated among participants |
| Transmission | Use of the high-voltage grid to move the energy | No, tariff regulated by the CNE |
| Distribution | Use of the local grid to deliver the energy at your point | No, tariff regulated by the CNE |
| Guarantees | Financial backing of your obligations to the operator | Indirectly, by sizing them well |
The regulator that sets and oversees these regulated tariffs is the Comisión Nacional de Energía (CNE), which replaced the former Comisión Reguladora de Energía (CRE) after the 2025 reform and assumed its functions. The practical consequence for your calculation: real savings appear only in the energy component, and that is why buying that component well —the spread, the node, the firm-versus-spot structure— is where profitability is decided. We develop this in energy management in the MEM.
What management and administration costs does it involve?
Participating in the MEM involves management and administration costs that don't appear on any tariff: you need someone to reconcile market billing, monitor Grid Code compliance, track node behavior, and administer the guarantees month after month. Operating inside the market is not "sign and forget"; it is a continuous function that costs money, whether in internal staff or in an external advisor.
These costs are the easiest to underestimate because they don't arrive on a labeled invoice. They arrive as the hours of an engineer who understands CENACE settlements, as a tracking software license, or as the risk of a fine for breaching the Grid Code if no one is watching. When a plant migrates without accounting for this layer, the projected savings dilute into operational problems no one had budgeted.
| Management cost | What it solves | Typical form |
|---|---|---|
| Billing reconciliation | Verify that what the market settles matches your real consumption | Internal staff or advisor fees |
| Node and LMP monitoring | Anticipate price variations in your load zone | Tracking software or managed service |
| Grid Code compliance | Avoid penalties for failing to meet technical requirements | Studies, maintenance, and periodic verification |
| Guarantee administration | Keep the financial backing correctly sized and current | Continuous financial management |
The underlying decision is who does this work. Building the internal team makes sense for very large, permanent loads; for most, a specialized advisor comes out cheaper than the total cost of ownership of doing it in-house. That comparison is part of what you assess when planning the migration, alongside everything else in migrating to the MEM: timelines, risks, and planning.
That continuous management is what turns a cost into a return: a company with operations in three states and 45,000 MWh per year sustains, thanks to weekly nomination evaluation since 2020, MX$24 million in savings in 2024 by mitigating precisely the deviations that would otherwise be additional charges (see the Northeast Multi-Point case).
Is it still worth it against the savings?
In most cases with sufficient volume, yes: the savings in the energy component comfortably exceed the sum of guarantees, fees, and management, and the net remains clearly positive. The key is volume. Because the entry and management costs are largely fixed, the more energy you consume, the more those costs dilute per kWh and the better the net looks. Savings scale with your consumption; several of the costs do not.
The net looks like this: you take the gross savings on the energy price, subtract the recurring portion of guarantees, operating fees, and management, and charge the one-time registration and transition costs against the first months. What's left is the real savings cash flow your plant sees each month.
| Component | Effect on the calculation |
|---|---|
| Gross energy savings | Adds (the main lever, grows with volume) |
| Guarantees | Subtracts (financing or opportunity cost, recurring) |
| Operation and grid fees | Mostly neutral: you pay them inside and out, they don't change the delta |
| Management and administration | Subtracts (recurring, largely fixed) |
| Registration and transition | Subtracts once (amortized over the first months) |
| Result | Net savings: positive and growing with the right volume |
Where the equation breaks: at small consumption, where fixed costs weigh too much per kWh; with poorly sized guarantees that tie up excess capital; or with a poorly negotiated contract that gives away the spread. That is why the volume threshold matters, and why it's worth understanding the boundary between qualified load vs. qualified user: the figure under which you enter the market also shifts your obligations and your costs.
How Enerlogix sizes the cost-benefit
At Enerlogix we don't sell you energy and we don't collect a supplier commission. We are an independent advisor, and our job is to put the real number in front of you before you migrate. Under the Plan 360 Management we measure first, decide with numbers, and execute only what pays for itself: we characterize your consumption profile, project the savings against your current tariff and your node's historical LMP, and subtract every cost in this article —guarantees sized to your profile, operation and grid fees, and the continuous management— to deliver the net savings cash flow, not the brochure gross.
That means before moving a single document you already know your payback, your 24-month net savings, and where every peso of cost is. If the numbers don't add up, we tell you and you don't migrate; if they do, we accompany you through registration, contract negotiation, guarantee sizing, and month-to-month management so the projected savings are the savings that actually arrive. That is the difference between buying a savings headline and buying a verifiable result.
Learn about the Qualified Users service or request a free evaluation. We work with your real bill and consumption profile, no obligation.
Frequently asked questions
Beyond the energy price, participating in the Wholesale Electricity Market brings financial guarantees required by CENACE, recurring fees for market operation and ancillary services, regulated transmission and distribution charges, and management costs such as billing reconciliation, Grid Code compliance, and guarantee administration. The real savings is the net after deducting all of that, not the gross savings the supplier promises.
CENACE, as the market operator, requires performance guarantees that back your payment obligations: cash deposits, letters of credit, or surety bonds. It is not a lost expense, but it ties up capital or carries a financing cost while you participate. The amount depends on your consumption volume and profile and on the rules in force, so there is no single figure; an oversized guarantee erodes net cash flow without you noticing it in the savings headline.
Three types are paid: the market operation CENACE provides, the ancillary services that keep the system stable, and the regulated transmission and distribution charges for using the grids. These charges are practically the same for all participants and are not controlled by the supplier; the regulated tariffs are set by the Comision Nacional de Energia, which replaced the former CRE in 2025. The negotiable savings live only in the energy component.
It involves reconciling market billing, monitoring the node and the LMP, complying with the Grid Code, and administering the guarantees month after month. These costs arrive as hours of specialized staff, tracking software, or the risk of fines if no one watches compliance. For most plants a specialized advisor comes out cheaper than the total cost of doing it with an internal team.
In most cases with sufficient volume, yes, because the savings on the energy price comfortably exceed the guarantees, fees, and management, and the net remains clearly positive. Because several costs are fixed, the more you consume the more they dilute per kWh. The equation breaks at small consumption, with poorly sized guarantees, or with a bad contract, so it is worth modeling the net with the real bill before deciding.
