This is a composite case based on real patterns handled by Enerlogix with white-goods and appliance manufacturing plants in northern Mexico. Some operational details have been modified to preserve confidentiality, but the figures, decisions, and lessons reflect real engagements.
The trigger was not the cost of energy: it was an email from corporate. The OEM customer —a global appliance brand— notified its supplier in Saltillo that, starting the next cycle, it would require evidence of clean energy consumption as a condition for remaining in the supply chain. The plant had two options: treat it as an unavoidable new cost, or solve it in a way that also lowered the bill. It chose the second.
The context
An appliance manufacturing plant in Saltillo, with 6.5 MW of contracted demand, assembles and manufactures components for a global brand. Continuous process, load factor of 0.68. Annual electricity spend of approximately MX$38 million.
The OEM requirement is part of a trend that is already standard in automotive and white-goods supply chains: the ESG audit of suppliers and carbon footprint reporting. What used to be a differentiator is today a condition for staying in. And for exporters, the European CBAM adds further pressure.
The diagnosis
The challenge broke down into three concrete questions:
- How to demonstrate clean energy consumption in a verifiable way acceptable to the OEM?
- What is the cheapest route to achieve it: buying Clean Energy Certificates, contracting a renewable mix, or installing on-site generation?
- How to build the ESG report with defensible data, not estimates?
The plant already qualified as a Qualified User but remained in CFE Basic Supply, which limited its access to CELs. That was the starting point.
The strategy · clean energy that also saves
The analysis compared three routes to meet the clean energy requirement, evaluating cost and verifiability, as in the ROI of a renewable portfolio vs buying CELs:
| Route | Relative cost | Verifiability | Effect on the bill |
|---|---|---|---|
| Buy CELs on the secondary market | Low per unit, recurring | High | Raises the bill |
| MEM contract with renewable mix + assigned CELs | Medium | High | Lowers the bill |
| On-site distributed generation (rooftop solar) | High upfront, low afterward | Very high | Lowers the bill long term |
The decision was a combination: migrate to a contract with a Qualified Supplier with a predominantly renewable mix, which assigned CELs to the plant and, at the same time, lowered the cost of energy relative to CFE. Rooftop solar generation was left as a second phase, financed with the savings.
It is the central finding of the case: clean energy did not have to be an extra cost. Structured as energy procurement via a Qualified Supplier, it met the ESG requirement and reduced the bill at the same time.
The execution
Phase 1 · Migration with renewable mix (months 1-5)
The migration to the Wholesale Electricity Market (MEM) was processed and an RFQ was launched explicitly requesting offers with a renewable mix and CEL assignment. The contract was negotiated prioritizing two objectives at once: a competitive price and a renewable percentage sufficient to cover the OEM's requirement.
Phase 2 · Emissions inventory and baseline (months 3-6)
In parallel, the emissions inventory for scopes 1, 2, and 3 was built with real consumption data, not estimates. The electricity consumption, now with a renewable mix and CELs, verifiably reduced scope 2 emissions.
Phase 3 · Defensible ESG report (months 6-7)
With the inventory data and the assigned CELs, the ESG report required by the OEM was assembled, with traceable documentary evidence: supply contract, CEL assignment, and consumption series. The relationship between energy and ESG is covered in ESG and sustainability in energy optimization.
Results at 12 months
| Item | Before | After |
|---|---|---|
| Supply regime | CFE Basic Supply | Qualified Supplier, renewable mix |
| Verifiable clean energy | No | Yes, with assigned CELs |
| Annual electricity cost | ~$38,000,000 MXN | ~$31,500,000 MXN |
| Annualized savings | — | ~$6,500,000 MXN (17%) |
| Status with the OEM | At risk | ESG requirement met |
| Financial item | Amount (MXN) |
|---|---|
| Total investment (CRE registration, fees, inventory, and report) | ~$1,400,000 |
| Annualized savings | ~$6,500,000 |
| Project payback | less than 3 months |
What weighed most with corporate was not the savings, but having turned a supply-chain condition into a cost-reduction lever. The plant complied with the OEM and lowered its bill by 17%.
Lessons from the case
1. ESG pressure is a lever, not just a cost
Most plants treat the clean energy requirement as an unavoidable new cost. Structured well —via a MEM contract with a renewable mix— it meets the requirement and reduces the bill. The mistake is buying loose CELs on the secondary market without touching the supply regime: that really is pure cost.
2. The ESG report needs data, not estimates
A report based on estimates is fragile under an OEM audit. Building the emissions inventory with real consumption data and documentary evidence of CELs makes the report defensible. Without reliable data, the report is a statement of good faith.
3. Qualifying and not migrating also costs on ESG
Remaining in CFE Basic Supply not only leaves savings on the table: it limits access to CELs and to a contractable renewable mix. For a plant under ESG pressure, migration has a double return: financial and compliance.
4. On-site generation is better as a second phase
Installing rooftop solar from day one would have delayed the solution and required capital. Solving first with the contract and leaving on-site generation for a second phase financed with the savings accelerates compliance without compromising cash.
Is your plant in a similar situation?
If your OEM customer began requiring evidence of clean energy or an ESG report, if you export to Europe and the CBAM reaches you, or if you have corporate decarbonization targets without a clear route, you are probably in a scenario comparable to this case.
At Enerlogix we integrate energy and sustainability into Plan 360 Management: we structure clean energy in the cheapest and most verifiable way, build the emissions inventory with real data, and assemble the defensible ESG report. Each case is different, but the pattern repeats.
Request a free evaluation or learn about our sustainable services. For the full framework, read CELs, RECs and ESG in Mexico 2026.
Frequently asked questions
Generally it is not buying loose Clean Energy Certificates on the secondary market, because that raises the bill without touching the supply regime. The most efficient route is usually to migrate to a contract with a Qualified Supplier with a predominantly renewable mix, which assigns CELs to the plant and at the same time reduces the cost of energy relative to CFE. In this case that combination met the OEM requirement and lowered the bill by 17%.
Yes, with a double return. Remaining in CFE Basic Supply limits access to CELs and to a contractable renewable mix. Migrating as a Qualified User to a contract with a renewable mix allows clean energy consumption to be demonstrated verifiably, reduces scope 2 emissions with real data and, in healthy load profiles, lowers the cost of energy. For a plant under ESG pressure, migration meets both the financial and the compliance objective at once.
Real data and traceable documentary evidence, not estimates. In this case the emissions inventory for scopes 1, 2, and 3 was built with the real consumption series, and clean energy was backed by the supply contract and the CEL assignment. A report based on estimates is fragile under an audit; one backed by a contract, certificates, and measured consumption is defensible.
It usually makes sense as a second phase, not as a first. Installing solar generation from the start delays the solution and requires capital. In this case the requirement was first solved with a MEM contract with a renewable mix, which met the OEM's requirement in a few months and lowered the bill, and rooftop solar generation was left as a second phase financed with the savings generated. This accelerates compliance without compromising cash.
In this case the total investment, including registration with the CRE, fees, emissions inventory, and ESG report, was around 1,400,000 MXN, against annualized savings of close to 6,500,000 MXN, with a payback of less than 3 months. The cost is low because most of the value comes from restructuring energy procurement, not from physical investment. The actual amount depends on the size of the plant and the state of its consumption information.
