Forward Curves & Term Structure

📖 Glossary · ← Learning Hub Lesson 5 Knowledge Power + Gas
How energy forward curves are constructed, why they differ from financial yield curves, and the role of seasonality, convenience yield, and storage in shaping the term structure.

The forward curve is the market's current consensus on future delivery prices — the term structure of energy. It is the foundation for valuation, hedging, and optimization: every structured contract, PPA, or storage dispatch decision references it. Yet energy forward curves behave fundamentally differently from financial curves because of non-storability (power) or costly storage (gas).

What Is a Forward Curve?

A forward curve maps delivery period → price for a given commodity and location at a given moment in time:

Price (€/MWh) 90 │ ╭──╮ 80 │ ╭──╮ │ │ ╭──╮ 70 │ ╭──╮ │ │ ╭──╮ │ │ │ │ 60 │ ╭──╮ │ │ │ │ │ │╭──╮ │ │╭──╮│ │ 50 │╭──╮│ │ │ │ │ │ │ ││ │ │ ││ ││ │ 40 ││ ││ │ │ │ │ │╭─┤ ││ │ │ ││ ││ │ 30 ││ ││ │ │ │╭┤ ││ │ ││ │╭┤ ││ ││ │ └┴──┴┴──┴─┴──┴┴┴──┴┴─┴──┴┴──┴┴┴──┴┴──┴┴──┴── Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 24 24 25 25 25 25 26 26 26 26 27 ←─ near-term ─→ ←── far-term ──→ (high liquidity) (low liquidity) Key features visible: • Winter peaks (Q1, Q4) > Summer troughs (Q2, Q3) — seasonality • Near-term quarters more volatile than far-term — uncertainty resolves • Back-end converging to long-run equilibrium — mean reversion

Power vs. Gas vs. Financial Curves

PropertyPower ForwardGas Forward (TTF)Financial Yield Curve
No-arbitrage link to spotWeak — non-storable, no cash-and-carryModerate — storage links carry cost to spreadStrong — bonds replicate forwards exactly
SeasonalityStrong (temperature + solar/wind patterns)Strong (heating demand, injection/withdrawal)None (or minimal)
Mean reversionStrong — marginal cost anchors long-runModerate — long-run supply/demand equilibriumWeak — rates can trend persistently
SpikesExtreme (scarcity pricing, 4000€ cap)Moderate (storage depletion events)Rare (crisis events only)
GranularityBase/Peak/Off-peak × hourly shapeMonthly/quarterly/seasonalContinuous term
Contango/BackwardationSeasonal — winter contango in summerStorage-driven (injection = contango)Yield curve slope analogous

Construction: From Traded Products to a Continuous Curve

The curve is constructed from observable market quotes — futures and forwards traded on exchanges (EEX, ICE) and OTC. The challenge: traded products have different delivery periods (months, quarters, years, base vs. peak), and you need a consistent hourly (or quarter-hourly) price for every delivery period.

Step 1: Collect Traded Quotes

ProductDeliveryTypeQuote (example)
DE Base Month Aug-25All hours of August 2025Baseload62.50 €/MWh
DE Peak Month Aug-25Peak hours (08-20 weekdays) of Aug 2025Peakload78.30 €/MWh
DE Base Quarter Q4-25All hours Oct-Dec 2025Baseload71.80 €/MWh
DE Base Year Cal-26All hours 2026Baseload65.40 €/MWh

Step 2: Cascading (Shaping)

Longer products are disaggregated into shorter ones, ensuring volume-weighted consistency:

The Cascading Constraint

PQuarter = (Σm∈Quarter hoursm × Pm) / Σm∈Quarter hoursm

A quarterly price must equal the weighted average of its constituent monthly prices. Similarly, a yearly price must cascade into quarters, and quarters into months. Where monthly prices are not directly traded, they must be inferred from the quarterly quote + seasonal shape assumptions.

Step 3: Base/Peak Decomposition

Deriving Off-Peak from Base and Peak

Pbase = (hourspeak × Ppeak + hoursoffpeak × Poffpeak) / hourstotal
∴ Poffpeak = (hourstotal × Pbase − hourspeak × Ppeak) / hoursoffpeak

With base and peak quotes, you can derive off-peak. The "peak" definition is typically Mon-Fri 08:00-20:00 CET (12 hours × ~22 weekdays per month). Off-peak = remaining hours (nights + weekends).

Step 4: Hourly Shaping

The final step transforms monthly base/peak prices into an hourly profile. This uses a shape factor — a normalized pattern derived from historical spot prices:

Hourly Price from Shape Factors

Ph = Pmonth,base × Sh

where Sh is the shape factor for hour h (average historical ratio of that hour's spot price to the monthly average). Σ Sh / N = 1 by construction. Shape factors capture the typical daily pattern: higher prices in morning/evening peaks, lower overnight.

Limitation: Shape factors are backward-looking. If the generation mix is changing (e.g., more solar depresses midday prices), historical shapes may not reflect future patterns. Advanced methods use fundamental models or recent shapes only.

The Storage-Arbitrage Link (Gas)

For storable commodities like gas, the forward curve is linked to spot via the cost of carry:

Cost-of-Carry Relationship

F(t,T) = S(t) × e(r + u − c)(T−t)

where: F = forward price, S = spot price, r = interest rate, u = storage cost (injection/withdrawal + capacity), c = convenience yield (value of physical inventory). If F > S + carry cost → inject (buy spot, store, sell forward). If F < S + carry cost → withdraw (sell spot, buy forward to replace).

Summer contango, winter backwardation: Gas forward curves typically show higher winter prices (heating demand) and lower summer prices. The summer-winter spread is bounded by the cost of storing gas from summer to winter (injection in Apr-Sep, withdrawal Oct-Mar). If the spread exceeds full-cycle storage cost, the arbitrage is profitable — and storage operators will inject until the spread narrows.

Why Power Has No Clean Arbitrage Link

Power cannot be stored cheaply at scale. This breaks the cost-of-carry relationship:

Implication for optimization: In gas, forward curve shape tells you about storage economics (contango = cheap storage). In power, forward curve shape tells you about expectations and risk appetite — not about arbitrage opportunities per se. A power trader selling Cal-26 is making a bet on future spot prices, not executing a riskless carry trade.

Key Curve Features for Optimization

FeatureWhat It SignalsOptimization Implication
Contango (far > near)Market expects higher future prices or values carryGas: inject now, sell forward. Power: sell forward if you disagree.
Backwardation (near > far)Current scarcity or convenience yield premiumGas: withdraw if physical. Power: near-term generation more valuable.
Steep seasonalityLarge winter/summer spreadStorage value high; flexible assets should capture seasonal spread.
Flat back-endMarket reverts to long-run equilibrium viewLess hedging value in far-term; limited information content.
Peak/Off-peak spreadIntra-day flexibility valueStorage/flex assets capture daily cycle; wide spread = high flex value.

Mark-to-Market and the Trading P&L

Forward curves are the valuation backbone for energy portfolios:

  1. Position valuation: Open forward positions are marked to the current curve. If you sold Cal-26 base at 65€ and the curve moves to 68€, you're underwater by 3 €/MWh × 8,760 hours = 26,280 €/MW
  2. PPA valuation: A fixed-price PPA is valued as the NPV of (PPA price − curve price) × expected volume over its term
  3. Asset valuation: A generation asset's value = Σ (curve − marginal cost) × expected running hours — the "intrinsic value" from the forward curve
  4. Optionality: Beyond intrinsic value, flexible assets have "extrinsic value" — the ability to respond to price moves not yet reflected in the curve
Your tangible win: You now understand how energy forward curves are constructed from traded products (cascading + shaping), why power curves differ fundamentally from gas curves (no arbitrage link vs. cost-of-carry), and how the curve's shape drives optimization and valuation decisions across the portfolio.

Primary Source

For the theory of energy commodity forward curves and the storage model:
Eydeland, A. & Wolyniec, K. (2003). Energy and Power Risk Management. Wiley. Chapters 3-5 on forward curve modelling remain the standard reference for energy quants.

For empirical analysis of power forward premia:
Bessembinder, H. & Lemmon, M. (2002). "Equilibrium Pricing and Optimal Hedging in Electricity Forward Markets." Journal of Finance, 57(3), 1347–1382. — Landmark paper on why power risk premia are systematically positive and vary with demand variance.

Retrieval Practice

Why can't the relationship F = S × e^(r+u-c)(T-t) be applied to electricity forward pricing?

Retrieval Practice

In the cascading step of forward curve construction, what constraint must be satisfied?

Retrieval Practice

A gas forward curve showing steep summer-winter contango (winter >> summer) signals that:

💡 Questions about curve construction methods, the Bessembinder-Lemmon model for power risk premia, how to use curves for PPA valuation, or the connection between curves and dispatch optimization? Just ask.

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