TUST Projection by Connection Point
Understand how transmission costs may evolve throughout your project and use the analysis to compare connections, set prices and make investment decisions.
Today's tariff is only the start of the analysis
The choice of connection point influences project costs for many years. Understanding the current TUST, Brazil's transmission system usage tariff, is only part of assessing that decision.
You also need to understand how this cost may evolve during operation and affect economic performance.
ePowerBay's TUST Projection by Connection Point helps turn this variable into a structured assumption for project planning.
The study addresses questions such as: which trajectory should the financial model use? How does a change in this assumption affect margins? How can connection alternatives be compared over the same period?
Why is adjusting the current tariff not enough?
TUST may change as the grid expands, transmission revenues evolve and costs are allocated among generation and consumption. Applying a fixed rate to the current tariff may not adequately represent that trajectory.
Investment decisions require assessing when the project will be exposed to the cost and for how long.
A seemingly small difference can become significant when accumulated over a contract. Comparisons should therefore consider the project's economic horizon as well as the first-year value.
How ePowerBay's projection works
The study tracks a specific connection through simulations and scenarios.
1. Identifying the connection
We check the substation, busbar, voltage, bus identification in the datasets and tariff regime. This correspondence avoids analyzing a bus other than the one associated with the project.
2. Organizing the datasets
We collect published grid configurations, revenues and parameters for available cycles, tracking the changes considered in the calculation.
3. Simulating with Nodal
We run calculations cycle by cycle and compare results with published references, checking the buses before using them in the projection.
4. Tracking tariff mechanics
We distinguish the calculated bus tariff, the tariff envelope limits and the applied tariff under the assumed regime. This helps explain how limits shape the trajectory.
5. Building subsequent scenarios
Beyond the horizon of applicable published configurations, we use extrapolation scenarios. Rates remain open and editable for sensitivity analysis.
6. Consolidating results
The report and spreadsheet present series, charts, datasets and assumptions, distinguishing simulations from scenarios. The work can compare connections and be updated after new cycles.
How to interpret the results
The projection should make both the values and their underlying assumptions understandable.
Identify which periods are supported by available datasets and which rely on extrapolation. Keep that distinction visible when incorporating figures into a financial model or presenting them to other teams.
A projection represents the conditions and assumptions considered in the analysis. It does not guarantee future tariffs.
Compare connection alternatives
Where several alternatives exist, assess them over the same horizon.
Alongside tariff differences, consider the expected operating date, required investment and technical conditions of each connection. The most suitable alternative depends on these factors together.
For example, a team can use the study to check whether transmission cost differences between two connections are material relative to the additional investment required for each option.
What you receive
Deliverables provide materials to interpret results and use them in planning:
Technical report: methodology, assumptions and interpretation of the trajectory.
Open spreadsheet: series, charts, tariff limits and scenarios.
Results discussion: according to the agreed scope.
The report provides decision-making context. The spreadsheet lets you track values and assess how changes in assumptions affect the project.
Where to apply the study
Pricing: incorporate transmission costs into economic planning and examine their influence on margins.
Long-term contracts: assess cost exposure throughout the contract term.
Connection selection: compare alternatives using consistent assumptions.
Asset valuation: review the transmission assumption in a project's financial model.
When integrating results, keep dates, units and monetary treatment consistent between the study and model.
How to request the study
Gather the project location, intended connection point, expected operating date and assessment horizon.
Explain the decision you need to support: analyzing a connection, comparing alternatives or reviewing an existing assumption. This information helps define a scope suited to your team's needs.