Tratamento do modelo vs. realidade fiscal: o modelo aplica depreciação linear sobre um único período configurável (depTerm) sobre a base CAPEX. Para concessão de transmissão (30 anos), usa-se depreciação ao longo do prazo da concessão, alinhado à ANEEL/RTP. O valor residual ao final do horizonte representa a indenização de ativos não amortizados ao término da concessão (base regulatória RAB), não um carry de valor contábil.

Ke is the minimum return rate that an investor requires to contribute equity capital to a project. It is the price of risk the investor assumes by giving up liquidity and accepting the uncertainty of future cash flows.

The equity investor has alternatives: sovereign bonds, real estate funds, other infrastructure projects. Ke is the return of the best equivalent-risk alternative — the opportunity cost of capital. If the project does not return at least Ke, the investor destroys economic value even if the project is profitable in absolute terms.

Component	Definition	Typical reference	Note
Rf — Risk-free rate	Return of an asset with no credit risk. Floor for any rational investment.	US Treasury 10yr (~4.5% in 2024) or local sovereign bond	No rational investor accepts below Rf. Represents the time value of money without a risk premium.
β — Project beta	Sensitivity of the project return to market variations. Measures systematic (non-diversifiable) risk.	β = 0.3–0.5 regulated transmission β = 0.6–0.9 generation with PPA β = 1.0–1.4 merchant generation	Projects with contracted revenue have lower β because their revenue is less exposed to the economic cycle.
(Rm − Rf) — Market risk premium	Additional return the market pays above the risk-free asset to compensate for systematic risk.	5% – 6% (developed markets, historical S&P 500 average)	Represents the compensation for investing in real assets instead of sovereign bonds.
Country Risk	Compensation for sovereign risk of the country where the project operates. Captures regulatory, political and macroeconomic risk.	Brasil: 150–250 bps (CDS 5y, Abr/2025) América Latina: 200–400 bps típico Ajustar conforme cenário macro atual	Measured by the sovereign CDS spread. Varies with the political and fiscal cycle of the country.
FX Risk	Aplicável quando o FCFE é em BRL mas o investidor mede retornos em USD.	Diferencial de inflação BRL/USD ou custo de hedge cambial	For projects with USD-denominated PPA revenue, this component is typically zero.

Project Type	Ke típico (BRL)	Ke typical (+ Brasil)	Justificativa do risk
Regulated transmission	7% – 9%	9% – 12%	Revenue guaranteed by regulatory contract. Very low volume risk. β ≈ 0.3–0.5.
Hydroelectric with long-term PPA	9% – 12%	11% – 14%	PPA elimina risk de price. Risk remaining: hidrologia e operation. β ≈ 0,6–0,8.
Wind / Solar with PPA	10% – 13%	12% – 16%	PPA reduces price risk but there is resource risk (wind, irradiation) and degradation. β ≈ 0,7–0,9.
Generation thermal power (despacho por ordem de merit)	11% – 15%	13% – 18%	Risk de despacho variable. Fuel cost impacts margin. β ≈ 0,9–1,2.
Generation a market (100% spot)	14% – 18%	16% – 22%	Maximum exposure ao price de energy. Alta volatilidade de revenue. β ≈ 1,2–1,5.

Reference: ANEEL WACC regulatory 2023 (transmissão ~8,6% real BRL), BNDES TJLP, dados de market ABRACEEL / EPE.

The lender has priority over the equity investor. In case of financial distress, the bank is paid first — principal, interest and real guarantees. The equity investor takes the residual risk: if everything goes well they gain more, if it goes wrong they lose everything. Essa assimetria exige um premium permanente.

If in the model Ke < Kd, there is an inconsistency in assumptions — the equity investor would be accepting a lower return than the lender for higher risk. This does not occur in an efficient market.

Situation	Condition	Equity NPV	Interpretation
Value creation	TIR equity > Ke	> 0	The project returns above the equity investor's cost of opportunity. Cada R$ investido gera valor econômico líquido positivo.
Economic indifference	TIR equity = Ke	= 0	The project only recovers the cost of opportunity. The equity investor is indifferent between this project and the equivalent-risk alternative.
Value destruction	Equity IRR < Ke	< 0	The project generates positive returns but below the minimum required. The equity investor would have done better in any equivalent-risk alternative.

Attention: it is possible to have a positive equity IRR (e.g. 10%) with negative equity NPV if Ke = 13%. The project is profitable — but not sufficiently to cover the opportunity cost of capital. This is the most common conceptual errors frequente na assessment de projects: confusing "profitable project" with "value-creating project".

Em project finance (ex: 70% debt / 30% equity), a leverage amplifica o return ao equity investor. Se o project returns 12% (project IRR) and debt costs 8% net, the leveraged equity may return 18%–24% — exactly what the model calculates as equity IRR.

This amplification works both ways: cheap debt relative to project IRR increases equity return; expensive or excessive debt can drive equity IRR below Ke even with a positive project IRR. DSCR measures the safety of this leverage — low values signal that debt service consumes most of EBITDA, leaving little for the equity investor in years of heavy amortization.