# Hedging commodity price risk across the energy value chain
It is 6 a.m. on a July morning. A heat wave is baking the grid, power prices are spiking, and you run treasury for a mid-sized gas-fired generator. Your plant only makes money when the price you get for electricity exceeds the cost of the gas you burn to make it. That gap is called the spark spread, and this morning it just collapsed because natural gas jumped faster than power. Every hour your plant runs, you could be losing money.
Your job is to make sure that does not happen. This lesson shows how.
Most people think energy hedging is about betting on whether prices go up or down. It is not. For a generator, the goal is to lock in a margin.
A spark spread is the theoretical gross margingross marginGross margin is the share of revenue left after subtracting the direct cost of producing goods or services, expressed as a percentage of revenue.View full definition → of a gas plant: the price of electricity minus the cost of the gas needed to produce it, adjusted for how efficiently the plant converts fuel to power. That efficiency is captured by the heat rate, measured in British thermal units (Btu) of gas needed per kilowatt-hour of electricity. A lower heat rate means a more efficient plant.
The rough formula:
Spark spread ($/MWh) = Power price ($/MWh)
- (Heat rate x Gas price ($/MMBtu))A plant with a heat rate of 7.0 (fairly efficient) burns 7 MMBtu of gas per MWh of power. If power sells for $50/MWh and gas costs $4/MMBtu, the spark spread is 50 minus (7 x 4) = $22/MWh. That $22 has to cover operating costs, maintenance, and profit.
Coal plants have an equivalent called the dark spread. When you add the cost of carbon allowances, you get the clean spark spread or clean dark spread, which matter enormously in markets with carbon pricing like the EU.
Energy sits at the intersection of two of the most volatile commodities in the world: natural gas and electricity. Power cannot be stored cheaply at scale, so its price can swing wildly within a single day. Gas storage helps, but supply shocks, pipelinepipelineAll active sales opportunities across the stages of the sales process, together with their combined potential value and probability of closing.View full definition → constraints, and weather still move prices fast.
That means your margin can vanish overnight even if you did nothing wrong operationally. Hedging is how a treasury desk turns an unpredictable margin into a defensible one.
You have three broad instrument types. Most desks blend all three.
A futures contract is a standardized, exchange-traded agreement to buy or sell a commodity at a set price on a future date. For gas in North America, the benchmark is the Henry Hub natural gas future traded on the CME. For power, there are regional futures tied to hubs like PJM or ERCOT.
Futures are liquid and transparent, and the exchange guarantees performance through a clearinghouse, which reduces counterparty risk. The tradeoff: they are standardized, so they may not match your exact plant location or delivery profile. That mismatch is called basis risk (more below).
A swap is a private, over-the-counter (OTC) contract where two parties exchange a floating price for a fixed price. If you want to lock in your gas cost, you can enter a swap where you pay a fixed price and receive the floating market price. If gas spikes, the swap pays you the difference, offsetting your higher physical purchase cost.
Swaps are flexible and can be tailored to your exact volumes and dates. The cost of that flexibility is counterparty credit risk and less transparency than an exchange.
You can also hedge in the physical market directly. A power purchase agreement (PPA) locks in a price for electricity you sell over months or years. A fixed-price gas supply contract locks in your fuel cost. A tolling agreement is especially relevant here: a counterparty pays you a fixed fee to run your plant, supplies the gas, and takes the power. That effectively transfers the spark spread risk to them.
Here is the elegant part. Instead of hedging power and gas separately, you can hedge the spread itself.
A spark spread option or a spread swap lets you lock in the margin between power and gas in one instrument. Some exchanges and OTC desks quote these directly. This matches your economic exposure far better than two separate hedges, because what you actually care about is the gap, not either leg alone.
Example scenario (illustrative numbers): Suppose it is spring 2026 and you expect to run heavily in summer. Forward power for July is $60/MWh, forward gas is $3.50/MMBtu, and your heat rate is 7.5. Your forward spark spread is 60 minus (7.5 x 3.5) = $33.75/MWh. If your cash operating cost is around $10/MWh, locking in that spread secures a roughly $24/MWh margin before overhead. You give up upside if spreads widen, but you protect against the heat wave scenario where gas spikes and crushes you.
Two problems keep energy treasurers awake.
Basis risk is the danger that your hedge and your actual exposure do not move together. You might hedge with a Henry Hub gas future, but your plant buys gas at a regional hub that trades at a different price. When the two diverge, your hedge is imperfect. Desks manage this with basis swaps that specifically hedge the price difference between two locations.
Volume risk (also called volumetric risk) is the danger that you hedge a fixed quantity but your actual output varies. A gas plant that expects to run 5,000 hours might only run 3,000 in a mild year. Now you are over-hedged: you have locked in sales of power you never produced, and you must buy it back at market. Renewables face an extreme version of this because wind and solar output is uncertain.
For a solid primer on how these markets and instruments fit together, the U.S. Energy Information Administration keeps an accessible explainer library at eia.gov/energyexplained.
🎬 [VIDEO: "Understanding Spark Spreads" — youtube.com — a concise walkthrough of how gas plant margins are calculated and hedged]
The spark spread is one seat. The same logic runs the length of the energy chain.
Upstream producers (oil and gas extraction) hedge to protect revenue against falling prices. A producer might sell crude or gas futures to lock in a price for next year's output, ensuring it can service debt even if prices drop.
Midstream and marketers hedge basis and storage. A company storing gas in summer to sell in winter locks in the seasonal spread with futures.
Utilities and retailers hedge to protect the price they promised customers. If a retailer sells fixed-price electricity plans, it must buy forward power so a price spike does not turn every customer into a loss.
Large industrial buyers (steel, chemicals, data centers) increasingly hedge energy costs directly or sign long-term PPAs, especially for renewable power, to stabilize their input costs and meet sustainability targets.
The instruments are similar. What changes is the direction of exposure: producers fear falling prices, consumers fear rising prices, and generators fear the spread narrowing from either side.
Knowledge check
1. Why is the primary goal of hedging for a gas-fired generator described as locking in a margin rather than a price?
2. A plant with a heat rate of 6.5 compared to one with a heat rate of 8.0 can best be described as:
3. What distinguishes a 'clean spark spread' from an ordinary spark spread?
4. Select ALL correct answers about why energy price risk is considered especially severe for a gas generator.
Select all the correct answers.
5. Select ALL correct answers that correctly describe spread concepts across the energy value chain.
Select all the correct answers.
A hedge reduces market risk but introduces other risks that treasury must manage.
Margin calls and liquidity. Exchange-traded futures require you to post cash margin (collateral) daily as prices move. A hedge that is deeply "in the money" for the exchange means you owe cash now, even though your offsetting physical gain comes later. In 2021 and 2022, several European utilities faced enormous margin calls when gas prices spiked, and some needed emergency financing. A good hedge with bad liquidity planning can still sink you.
Hedge accounting. Under accounting standards, derivatives are marked to market, which can whipsaw reported earnings. Companies use hedge accounting treatment to align the timing of hedge gains and losses with the underlying exposure, but it requires strict documentation.
Policy limits. Serious desks operate under a board-approved risk policy that sets how much of expected output can be hedged, which counterparties are approved, and who can trade. This prevents hedging from quietly turning into speculation.
None of this is investment advice. The point is that hedging is a discipline, not a trade.