Evaluate midstream infrastructure investments using Net Present Value (NPV), Internal Rate of Return (IRR), and discounted cash flow (DCF) analysis per AACE International and SPE guidelines.
Net Present Value (NPV) is the gold standard for capital budgeting decisions. It measures the absolute dollar value a project adds to shareholder wealth by discounting all future cash flows to present value and subtracting the initial investment.
NPV Definition
Sum of discounted cash flows
Present value of all future cash flows minus initial investment.
Decision Rule
NPV > 0: Accept
Positive NPV means project creates shareholder value.
Key Advantage
Measures absolute value
Unlike IRR, NPV shows actual dollars of wealth created.
Discount Rate
WACC or hurdle rate
Use company's weighted average cost of capital.
NPV Formula
Net Present Value:
NPV = -I₀ + CF₁/(1+r)¹ + CF₂/(1+r)² + ... + CFₙ/(1+r)ⁿ
Or in summation notation:
NPV = Σ [CFₜ / (1 + r)ᵗ] for t = 0 to n
Where:
I₀ = Initial investment at t=0 ($)
CFₜ = Cash flow in period t ($)
r = Discount rate (WACC, decimal)
n = Project life (years)
NPV Cash Flow Timeline: Initial investment at Year 0, annual cash flows discounted to present value, with terminal value including salvage and working capital release.
IRR ignores scale; $50M project with 12% IRR may beat $5M project with 20% IRR
Non-conventional cash flows
Yes
No
Multiple sign changes create multiple IRRs
Single project go/no-go
Yes
Yes
Both give same accept/reject decision
Management communication
No
Yes
IRR as % is easier to communicate than NPV in $
NPV Rule: When NPV and IRR rank projects differently, always use NPV. NPV assumes cash flows are reinvested at WACC (realistic), while IRR assumes reinvestment at IRR itself (often unrealistic for high-IRR projects).
2. IRR & MIRR Methods
Internal Rate of Return (IRR) is the discount rate that makes NPV equal to zero. It represents the project's effective annual return. However, IRR has limitations that Modified IRR (MIRR) addresses.
IRR Formula
IRR Definition:
Find r such that NPV = 0:
0 = -I₀ + CF₁/(1+IRR)¹ + CF₂/(1+IRR)² + ... + CFₙ/(1+IRR)ⁿ
Decision Rules:
- IRR > WACC → Accept project
- IRR < WACC → Reject project
- IRR = WACC → Indifferent (NPV = 0)
IRR cannot be solved algebraically for n > 2.
Use Newton-Raphson iteration or financial calculator.
NPV Profile Chart: NPV decreases with higher discount rates. IRR occurs where curve crosses zero. Accept projects when discount rate < IRR (NPV > 0).
MIRR solves two IRR problems: (1) unrealistic reinvestment assumption and (2) multiple IRRs with non-conventional cash flows.
MIRR Formula:
MIRR = [(FV of positive CFs / |PV of negative CFs|)^(1/n)] - 1
Where:
- Positive CFs compounded forward at reinvestment rate (typically WACC)
- Negative CFs discounted back at finance rate (cost of debt or WACC)
FV = Σ [CFₜ × (1 + r_reinvest)^(n-t)] for CFₜ > 0
PV = Σ [|CFₜ| / (1 + r_finance)^t] for CFₜ < 0
MIRR is always unique (single solution).
MIRR < IRR when IRR > reinvestment rate (typical case).
Example: IRR vs MIRR Comparison
Pipeline Project:
Cash flows: CF₀ = -$10M, CF₁...₈ = $2.5M/year
WACC = 10%
IRR Calculation:
By iteration: IRR = 18.7%
MIRR Calculation (reinvest at 10%):
FV of positive CFs = $2.5M × [(1.10)⁷ + (1.10)⁶ + ... + 1.0]
FV = $2.5M × 11.436 = $28.59M
PV of negative CF = $10M (at t=0)
MIRR = ($28.59M / $10M)^(1/8) - 1
MIRR = (2.859)^0.125 - 1
MIRR = 14.1%
MIRR (14.1%) < IRR (18.7%)
MIRR is more realistic because it assumes reinvestment at WACC (10%), not at IRR (18.7%).
Multiple IRR Problem
Cash Flow Pattern
IRR Count
Example
Solution
Conventional (-, +, +, +)
1 unique
Standard pipeline project
Use IRR normally
Non-conventional (-, +, +, -)
0, 1, or 2+
Mining with reclamation cost
Use NPV or MIRR
All negative
None
Pure cost project
Use cost-benefit analysis
Best Practice: Many midstream companies now require both IRR and MIRR for capital approval. MIRR provides a more conservative, realistic return estimate. Use MIRR when comparing projects with different cash flow timing patterns.
3. WACC & Discount Rates
The Weighted Average Cost of Capital (WACC) represents the blended cost of all capital sources. It is the appropriate discount rate for projects of average risk. Project-specific risk adjustments may be added.
WACC Formula
Weighted Average Cost of Capital:
WACC = (E/V) × rₑ + (D/V) × r_d × (1 - T_c)
Where:
E = Market value of equity ($)
D = Market value of debt ($)
V = E + D = Total firm value ($)
rₑ = Cost of equity (%)
r_d = Cost of debt, before tax (%)
T_c = Corporate tax rate (%)
(1 - T_c) = Tax shield on interest
Target capital structure:
E/V = Equity weight (typically 50-70% for midstream)
D/V = Debt weight (typically 30-50% for midstream)
WACC Components: Weighted average of cost of equity (via CAPM) and after-tax cost of debt, reflecting target capital structure.
Discount Rate Sensitivity: A 2% change in WACC can swing NPV by 20-30% for long-lived infrastructure. For a 20-year project with $100M investment and $15M/year cash flows: NPV at 8% = $47M, NPV at 10% = $28M (40% lower). Always test sensitivity to discount rate assumptions.
4. Cash Flow Analysis
Accurate cash flow forecasting is the foundation of reliable NPV/IRR analysis. Free Cash Flow to Firm (FCFF) is the appropriate measure for project evaluation.
Free Cash Flow Formula
Free Cash Flow to Firm (FCFF):
FCFF = EBIT × (1 - Tax) + Depreciation - CAPEX - ΔWC
Or equivalently:
FCFF = Revenue - OPEX - Taxes + Depreciation × Tax - CAPEX - ΔWC
Where:
EBIT = Earnings before interest and taxes
Tax = Marginal corporate tax rate (21% federal + state)
Depreciation = Non-cash charge (creates tax shield)
CAPEX = Capital expenditures
ΔWC = Change in working capital (increase = outflow)
Note: Interest is NOT subtracted from FCFF.
WACC already accounts for financing costs.
Depreciation Tax Shield
Depreciation reduces taxable income, creating a "tax shield" that increases after-tax cash flow. Accelerated depreciation (MACRS) provides higher tax shields in early years, increasing NPV.
MACRS vs. Straight-Line Depreciation: MACRS front-loads deductions, providing higher tax shields in early years and increasing NPV compared to straight-line depreciation.
MACRS 15-Year Schedule (Pipelines)
Year
Rate
Year
Rate
1
5.00%
9
5.91%
2
9.50%
10
5.90%
3
8.55%
11
5.91%
4
7.70%
12
5.90%
5
6.93%
13
5.91%
6
6.23%
14
5.90%
7
5.90%
15
5.91%
8
5.90%
16
2.95%
Working Capital
Working Capital Treatment:
Working Capital (WC) = Current Assets - Current Liabilities
= Inventory + Receivables - Payables
Year 0: WC investment = cash outflow
Years 1-n: ΔWC = additional outflow if revenue grows
Final Year: WC release = cash inflow (recovered at project end)
Midstream WC Requirement: Typically 5-10% of annual revenue
- Limited inventory (gas flows through)
- Short collection cycles (monthly billing)
- Long payment terms with suppliers
Terminal Value
Terminal Value Methods:
1. Salvage Value (asset-based):
TV = Estimated market value at end of analysis
Typical for pipelines: 20-40% of original cost
Tax on gain: (Salvage - Book Value) × Tax Rate
2. Perpetuity Growth Model:
TV = FCF(final) × (1 + g) / (WACC - g)
g = perpetual growth rate (typically 0-2%)
3. Exit Multiple:
TV = EBITDA(final) × EV/EBITDA multiple
Midstream multiples: 8-12× EBITDA
Terminal value often represents 30-50% of total NPV
for long-lived infrastructure projects.
Cash Flow Accuracy: NPV is most sensitive to near-term cash flows due to discounting. A 10% error in Year 5 cash flow has 10× more impact than a 10% error in Year 25. Focus forecasting effort on Years 1-10; far-future cash flows can use simplified assumptions.
5. Sensitivity & Risk Analysis
Sensitivity analysis tests how NPV/IRR change with key input variables. For midstream projects, the primary sensitivities are typically throughput volume, commodity prices (for processing plants), CAPEX, and discount rate.
One-Way Sensitivity (Tornado Chart)
Sensitivity Analysis Process:
1. Identify key variables (typically 5-8 drivers)
2. Define range: ±10%, ±20%, or min/max bounds
3. Vary one variable, hold others at base case
4. Calculate NPV at each scenario
5. Rank by impact (tornado diagram)
Example Results ($100M pipeline, base NPV = $50M):
Variable | -10% | Base | +10% | Swing
------------------|---------|--------|--------|-------
Throughput volume | $18M | $50M | $82M | $64M
Discount rate | $68M | $50M | $35M | $33M
CAPEX | $60M | $50M | $40M | $20M
OPEX | $56M | $50M | $44M | $12M
Ranking: Volume > Discount Rate > CAPEX > OPEX
Tornado Sensitivity Diagram: Variables ranked by NPV impact. Throughput volume is the primary driver; OPEX has minimal effect. Red/green bars show NPV range from low to high scenarios.
Probabilistic Analysis:
Define probability distributions for uncertain variables:
- Volume: Log-normal (mean 200, std dev 30 MMcf/d)
- CAPEX: Triangular (min $90M, mode $100M, max $120M)
- Tariff: Uniform ($0.45 to $0.55/Mcf)
Run 10,000+ iterations:
- Sample each variable from its distribution
- Calculate NPV for each iteration
- Build probability distribution of outcomes
Results:
- Expected NPV (mean): $48M
- Standard deviation: $25M
- P(NPV > 0): 85%
- P(NPV > $50M): 45%
- VaR (P10): NPV > $8M with 90% confidence
Decision: 85% probability of positive NPV is acceptable
for most corporate risk tolerances (>70% threshold).
Monte Carlo NPV Distribution: Probabilistic analysis from 10,000 simulations shows 85% probability of NPV > 0. P10/P50/P90 values quantify uncertainty range.
Industry Practice: Most midstream companies require projects to show positive NPV in both base case and pessimistic (P90) scenarios before approval. The "sanction hurdle" is typically IRR > WACC + 2-3% to provide buffer for execution risk and model uncertainty.