When an industrial company accepts a sustainability target —because an OEM, a bank, or management demands it— the first financial decision is this: is it better to invest in your own renewable generation or simply buy Clean Energy Certificates (CELs) and RECs to comply on paper? The answer completely changes cash flow and the balance sheet, and many companies choose poorly because they compare apples to oranges: they treat a compliance purchase as if it were an investment, or an investment as if it were an expense.
This article puts the options side by side with figures in pesos, so the decision is financial and not emotional. The decisive criterion, we'll say up front, is not which is "greener": it is what you want to achieve —meet a requirement or reduce your energy cost—.
The three routes to reduce your Scope 2 footprint
Every clean-energy strategy for your Scope 2 falls into one of three routes, or a combination:
- Route A — Buy CELs/RECs: certificates that prove clean generation equivalent to your consumption. You don't change your physical energy; you change the reported attribute.
- Route B — Renewable PPA (off-site): a long-term contract to buy energy from a solar or wind farm, typically via a Qualified Supplier in the MEM.
- Route C — On-site generation: rooftop panels, cogeneration, or storage inside your plant.
Route A: buying CELs and RECs
It is the simplest and cheapest option per unit. You certify clean energy without touching your installation or your electricity contract.
- CELs (Mexican market): typical price MX$80 to MX$220 per CEL (1 MWh). In 2026 the regulatory obligation for Qualified Users is around 13.9% of consumption.
- RECs (international I-REC market): USD $1.50 to $5.00 per REC, for voluntary targets and reports to global customers.
What it solves: regulatory compliance and a reportable renewable attribute. What it does not solve: it does not lower your electricity rate by a single peso. You keep paying for the same physical energy. We go deeper in CELs: what they are and how to leverage them and in the pillar CELs, RECs and ESG in Mexico 2026.
Route B: off-site renewable PPA
You sign an energy purchase contract with a renewable generator, typically for 10–15 years, accessing the MEM as a Qualified User. Here clean energy does replace your physical energy.
What it solves: it substantially lowers your Scope 2 and usually reduces your energy cost versus the CFE tariff, because you capture competitive renewable generation prices. The required own capital investment is low (it is a contract, not an asset), but it ties you to a long-term commitment and demands careful negotiation of the band and the guarantees.
Route C: owned on-site generation
You install assets at your plant: rooftop solar, efficient cogeneration, storage. Maximum control, maximum investment.
What it solves: the greatest predictability of cost and emissions over the long term. What it costs: high upfront capital, physical space, and a long operating horizon to amortize.
Side-by-side ROI comparison
| Criterion | A · CELs/RECs | B · Renewable PPA | C · Owned on-site |
|---|---|---|---|
| Upfront investment (3 MW plant) | $0 (annual expense) | Low (contract) | High — $8M to $40M+ MXN |
| Indicative annual cost | $200,000 – $400,000 MXN | Cuts bill 10–25% | Amortizes over years |
| Scope 2 reduction | "Market-based" only | 30–80% | Up to 100% of what is generated |
| Effect on electricity rate | None | Lower | Strong reduction |
| Payback | Not applicable (expense) | Immediate to 2 years | 5–10 years |
| Complexity | Low | Medium | High |
The figures are indicative for a 2–5 MW plant; your case depends on load zone, load factor, and consumption profile.
The decisive factor: comply or reduce cost?
The right question is not "which is greener?" but what problem you are solving:
- If your goal is to meet the minimum (CEL obligation + a customer requirement) without moving your operation: Route A. Low cost, high simplicity, zero ROI because it is a compliance expense.
- If you want to lower your Scope 2 and your bill at the same time: Route B. It is where the best ROI is for most Mexican plants today, because it combines a renewable attribute with cheaper energy.
- If you have land, capital, and a long horizon: Route C, or a B+C hybrid.
The hybrid scenario (the most common and profitable)
In practice, the strategy that pays off best combines routes: a renewable PPA that covers the bulk of consumption (lowers Scope 2 and rate), complemented with CELs to close the regulatory obligation and occasional RECs for the voluntary targets of specific customers. This way you neither overinvest in your own assets nor fall short on compliance. Arriving at an ESG audit by your OEM with that package already contracted gives a clear advantage over those who only promise.
This logic of "operating the right levers in the right order" is the same one that applies to efficiency: see Top 10 energy efficiency measures with the best ROI.
How the decision looks across three plant sizes
The optimal route changes with scale and consumption profile:
- Small plant (consumption < 5,000 MWh/year): usually Route A. The volume does not justify the complexity of a PPA or the capital of owned generation; buying CELs for the obligation and occasional RECs for customers is the most efficient.
- Mid-sized plant (5,000–20,000 MWh/year): the sweet spot for the hybrid. A renewable PPA via a Qualified Supplier lowers Scope 2 and rate at the same time, complemented with CELs to close compliance. Here is the best ROI for most Mexican industries.
- Large consumer (> 20,000 MWh/year, with land): it is worth modeling owned on-site generation or a larger-volume PPA, weighing the capital against cost predictability over 10–15 years.
The variable that moves the result the most is not size itself, but your load factor and your load zone at CENACE: a stable profile in a zone with a good LMP price makes the PPA pay off much more.
Next step
The decision between buying attributes or investing in renewables should come out of a financial model with your real data: your load zone, your load factor, and your LMP price. At Enerlogix we build that model within the 360 Management Plan and our sustainable services, and we deliver the route with the best ROI for your case, with no supplier bias.
Request a free evaluation of the 360 Management Plan and we review which mix of CELs, PPA, and owned generation suits you.
Frequently asked questions
The typical price of a CEL, which equals 1 MWh, runs from 80 to 220 MXN in the Mexican market. In 2026 the regulatory obligation for Qualified Users is around 13.9% of consumption. RECs from the international I-REC market cost between 1.50 and 5.00 dollars and serve voluntary targets and reports to global customers.
No. Buying CELs or RECs solves regulatory compliance and gives you a reportable renewable attribute, but it does not lower your electricity rate by a single peso, because you keep paying for the same physical energy. To lower Scope 2 and the bill at the same time you need a renewable PPA, which replaces your physical energy with cheaper clean energy.
For most Mexican plants today, the off-site renewable PPA offers the best return: it lowers Scope 2 between 30 and 80 percent and reduces the bill between 10 and 25 percent, with low capital investment because it is a contract. Buying CELs has no ROI because it is a compliance expense, and on-site generation amortizes in 5 to 10 years.
Yes. You normally access the PPA via a Qualified Supplier as a Qualified User, with a typical contract of 10 to 15 years. That also opens the possibility of lowering your rate. The variable that moves the result the most is not the size of the plant, but your load factor and your load zone at CENACE.
The hybrid scenario. The most common and profitable approach combines a renewable PPA that covers the bulk of consumption, which lowers Scope 2 and rate, complemented with CELs to close the regulatory obligation and occasional RECs for the voluntary targets of specific customers. This way you neither overinvest in your own assets nor fall short on compliance.
It counts for the market-based report of the GHG Protocol, known as market-based, but it does not change your physical energy or your location-based factor. That is why some global customers no longer accept CELs alone and demand real emission reduction via a renewable PPA, which does replace the physical energy your plant consumes with clean generation.
It depends on the route. A well-structured PPA includes bands that absorb reasonable variations in your consumption. CELs simply adjust year by year in proportion to what you consume. On-site generation, by contrast, is fixed at its installed capacity, so a strong demand increase can leave it short and force you to complement it with another route.
