Demo · solar PV curtailment
Curtailment calls for better decisions.
See how engineering can support constraint forecasting, metering checks and maintenance planning.
Public data from ONS (Brazil’s national grid operator) and CCEE (Brazil’s power trading chamber), and a simulated plant. The demo shows the method applied to a real problem. It is not the product.
I am an entrepreneur, and I fall in love with the client’s problem. I don’t start from a one-size-fits-all solution. I study the problem with your team until we find the best solution for your operation.
Restricted access, with a username and password provided by Serra Pereira.
Why it matters
Three decisions a manager makes without seeing what comes next.
When the grid cannot take the energy, ONS orders plants to reduce output. Curtailment costs generation. It also affects metering, the team and the equipment.
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01
Will there be curtailment tomorrow, and how much?
Without a forecast, operations react after ONS orders the cut. With one, they plan the team and the asset ahead of time.
In the demoA 48-hour curtailment forecast, with its error measured against the 30-day historical baseline.
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02
Does the settled amount match what the plant could generate?
When metering data is missing, CCEE fills the gap with an estimate. The estimate can fall below actual generation.
In the demoThe estimation rule in Annex 7.2 of CCEE’s Submódulo 2.1 (opens in a new tab), applied to the history with each hour’s PLD (opens in a new tab) (hourly spot price).
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03
When should each inverter be serviced?
A fixed calendar is simple, but it ignores the condition of the equipment and the hour when stopping costs less.
In the demoCondition-based decision rules compared with the calendar, in a simulated plant and a simulated portfolio.
How it works
Forecast to decide ahead. Measure to correct afterward.
The forecast is not the product. It is the model of the process. It exists so that the decision is made before the fact, within the limits of the asset, and checked afterward.
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01
Forecast
Curtailment over the next 48 hours, with the error measured.
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02
Compare options
Each hour ahead becomes a choice with a price.
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Decide under constraints
The option that yields the most without exceeding the asset’s limit.
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04
Measure results
What happened is recorded and checked.
what happened comes back measured and corrects the next decision
What is demonstrated, what is simulated and what comes with the client’s data
| Demonstrated | Simulated | With the client’s data | |
|---|---|---|---|
| Forecast | 48-hour generation curtailment on the public ONS history (opens in a new tab), error measured out of sample | — | plant generation, with weather and the client’s telemetry |
| Maintenance | — | calendar, threshold and rolling-horizon rules in a plant and in a portfolio | real inverter signals and a link to the forecast |
| Metering and CCEE | estimation rule in Annex 7.2 of Submódulo 2.1 (opens in a new tab), applied to the history with each hour’s PLD (opens in a new tab) | — | SCDE data-origin report and metering evidence |
| Cross-check | Excel and MATLAB recompute the published quantities, with the stated scope | — | physical condition of the real asset |
The demo
Each screen answers one question.
Each indicator shows where the data comes from and the method. Anything simulated is marked as simulated.
Since September 2026, the demo also answers what curtailed energy can become, at what price, how long it takes to pay back, how long until it produces and how many hours a year it operates. All with the stated rule, a downloadable spreadsheet with live formulas, and per-user access with permissions per tab.
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Public data · ONS · screen in PortugueseWhere and when does curtailment happen?
The public ONS history (opens in a new tab), by plant, by hour and by season. It is the starting point for any decision.
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Diagram · numbers in the demoWhat can curtailed energy become?
Four routes for curtailed energy: industrial products and storage. The rule is stated in the demo: a second company and plant energy at cost price. The table shows what each route must sell, how long it takes to pay back and how much profit it makes over its useful life, as a percentage of investment.
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Diagram · numbers in the demoHow long until production starts?
Seven phases per route, what runs in parallel and the critical path, counted from the first disbursement. Durations only where there is a public source. The rest stays as an open item, so the total is a minimum, not a forecast. The timeline enters the cash flow: interest until the first revenue, and the payback counted both ways.
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Diagram · numbers in the demoHow many hours a year does each route operate?
Utilization as a percentage of the year, equivalent hours, production and the energy that comes from outside curtailment, by route and scenario. Where something is an assumption, it is labeled as one: the 100% figure does not account for unavailability. Continuous operation of a route depends on a reserve that covers the longest gap in the history.
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48-hour forecast · screen in PortugueseIs the forecast error smaller than the baseline’s?
Forecast curtailment against actual curtailment, with the error measured out of sample. The scoreboard also shows when the improvement cannot be told apart from the baseline.
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Simulation · stated assumptions · screen in PortugueseHow much does condition-based management save, and where does it come from?
A simulated portfolio with the prices provided, broken down into steps: organized fleet, alarm response, condition-based decisions and curtailment forecasting. With a confidence interval.
Can every number be checked?
Spreadsheets and MATLAB scripts recompute the published quantities. The package states what was recalculated, what uses exported predictions and what is left out of the check.
Latest reviewed verification: September 28, 2026
- package 2026-09-28_1827
- 12 of 12 stages green
- comparison with the platform OK
- scripts run without errors on the MATLAB R2026a engine, reviewed and approved by Fabio Serra Pereira
Full platform verification on the same day: 1,255 tests, 236 cross-checks and 12 of 12 stages in MATLAB.
Future opportunity
Storage: the same control problem.
The 2026 LRCAP (capacity reserve auction) contracts power availability. ONS dispatches the battery, the project owner receives a Fixed Revenue (Receita Fixa), and settlement at the PLD goes to CONCAP. The project owner’s job is to keep the asset available, efficient and healthy.
Outside the auction, a battery at the plant can store curtailed energy and deliver it later. The decision is when to charge, when to deliver and how much the asset can take.
Portaria Normativa MME nº 136/2026 (MME: Ministry of Mines and Energy) (opens in a new tab)Engagement
Serra Pereira does not sell software. We sell knowledge of control and analysis.
What we offer: a cost calculation methodology (investment analysis is one way to analyze cost), IoT and industrial strategies, and above all how to instruct AI so your team can build its own platform.
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Defining the work
The timeline comes after, with the scope in hand.
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The analysis
Where the operation loses money today and the best way to invest. The calculations are redone outside the system and checked against operations. It ends in a number and a verdict, and a no is also a deliverable.
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Your platform
Your team builds it with AI, guided by the method, and it runs in your environment.
How the service works day to day
- Scope, not hours. Agreed deliveries and milestones, with no exclusivity and no tracking of working hours.
- Follow-up. WhatsApp, email and phone, plus recurring online meetings at the frequency the client sets.
- In-person meetings by appointment. Outside the state of São Paulo, travel is paid by the client.
- Infrastructure. The platform runs in the client’s environment. Server costs are paid by the client, and the work adapts to what the client already has.
Use of materials
Scripts, spreadsheets and documentation produced in the work belong to the client.
Pre-existing components and third-party libraries keep their own licenses.
Next step
Talk to us about your scenario.
Bring us your operation’s problem. The demo is available to explore with the access provided, and it can remember your device for up to 7 days.
Fabio Serra Pereira · Mechanical engineer · CREA-SP 5071933433