1. The short answer
For a plant paying more than MXN 200,000 a month for energy, the shortest answer is that the BESS does not have to cost you anything upfront. Under shared savings, ENEGRIN designs, installs, operates, maintains and insures the system. Each month you pay a percentage of the savings the system has already generated, measured with two meters and your tariff’s formulas.
You take on no debt, post no financial guarantees, and your credit lines remain available. And by contract, you never pay more than you would have paid without the system. The two contracting models
2. No-investment BESS: the three models you will find in Mexico
Several companies in Mexico offer BESS without you buying the equipment. The difference is what you pay each month and what happens in a month with no savings.
| Fixed rent | Service fee | Shared-savings contract (ENEGRIN) | |
|---|---|---|---|
| What you pay each month | A fixed rent for the equipment | A fixed or indexed fee for the service | A percentage of the measured savings |
| In a month with no savings | You pay the rent | You pay the fee, unless the contract says otherwise | You pay nothing |
| Who operates and maintains it | Set by the contract | The provider | ENEGRIN |
| Guarantee against your bill | Set by the contract | Set by the contract | By contract, you never pay more than you would have paid without the system |
| How savings are calculated | Set by the contract | Set by the contract | Two meters and your tariff’s formulas, every month |
Other providers’ models vary. Ask each one for the contract and the measurement method in writing.
3. What determines the size of the system?
A BESS is sized with two numbers: power in kW, which is how much it can deliver at any instant, and energy in kWh, which is how much it can deliver in total before recharging. Both come from your load curve.
- Power (kW). Set by the demand peak you want to trim during peak hours and, if you want backup, by the load it must carry during an outage: the whole plant or only part of it.
- Energy (kWh). Set by your tariff’s peak hours (under GDMTH, the most expensive band of the day) and the backup autonomy you need, typically 2 hours at full discharge.
- Tariff and region. Time bands and charges change by CFE division and by season, which is why the same kWh is not worth the same in Norte as in Baja California. GDMTH tariff by division
Sizing is done with your consumption data, not with averages. A system larger than necessary does not save more: it saves the same and costs more.
4. What you pay each month under shared savings
A percentage of measured savings. Savings are calculated every month with two certified meters and your tariff’s formulas: what you would have paid CFE without the system, minus what you paid. From that difference come the operation and maintenance fee and ENEGRIN’s share. The rest is yours.
If savings are lower one month, you pay less. If there are no savings, you pay nothing. On ENEGRIN BESS operating in Mexico, measured savings on the CFE bill range from 27% to 37%, depending on season and consumption pattern. The exact split is set in your proposal, based on your bills. How we measure and reconcile
5. What if you prefer to buy the system?
You can buy it at the outset or later on, whenever you want, during the contract. The price depends on the size in kW and kWh, the type of cabinet or container and the electrical works at your plant, and it comes in a proposal based on your data.
When you buy, the savings are yours and you pay only the operation and maintenance fee, which is also a percentage of measured savings. The guarantee is the same: you never pay more than you would have paid without the system, with the O&M contract in force.
6. What should not cost you extra
When comparing proposals, check what is included. Under ENEGRIN’s no-investment model, all of this is on ENEGRIN:
- The CENACE technical study and Grid Code compliance. Which permit a BESS requires
- Electrical works, installation and connection, without stopping your plant: only the final connection requires a brief, scheduled outage.
- Maintenance, repairs, component replacement and insurance for the system.
- The Ollin Platform, where you see your savings every month, with unlimited users per plant and read-only access for your auditor.
7. How to get your plant’s figure
The Ollin Simulator calculates your savings with your plant’s consumption data and, if you prefer, with your CFE bill. It tells you right away how much you would save and which system we recommend, with its size in kW and kWh. The formal proposal, with both models, follows based on your bills.
Use the Ollin Simulator to estimate the BESS size your plant needs and what it would save.
The simulator asks you to create an account with your company email. Actual savings are measured every month once the system is running at your plant.