What is firm power?

Firm power is electricity the seller guarantees to deliver whenever the buyer calls for it — around the clock, at full contracted capacity, regardless of weather, season, or what the rest of the grid is doing. The opposite is non-firm supply: interruptible service a seller can curtail, or as-available output that flows only when conditions allow. Firmness is a promise, and everything that matters about firm power is in how that promise is engineered and enforced.

The three grades of supply

Power contracts sort into three grades. Firm supply carries a delivery guarantee: a stated capacity, a stated availability level, and remedies owed if the seller falls short. Interruptible supply is cheaper because the seller keeps the right to curtail it when the system is tight — the buyer is the shock absorber. As-available supply follows the resource rather than the load: energy arrives when the wind blows or the sun shines, not when the servers ask for it.

The grades are not good, better, best. They are different products for different buyers. A flexible industrial load can monetize interruptibility. A load that cannot stop has no use for it.

Why AI loads buy firm

An AI data center runs close to flat-out, continuously, and the capital inside it is most expensive when idle. A curtailment does not merely pause work; it strands an enormous investment in silicon and can disrupt training runs that span weeks. Interruptible supply hands the grid's scarcity problem to the one buyer least equipped to absorb it. That is why serious compute loads contract for firm capacity and treat everything else as supplemental.

How firmness is engineered

No single generator is firm — every machine eventually needs maintenance or suffers a forced outage. Firmness is built at the system level: more units than the load requires, so any one machine can drop out without the load noticing; fuel under firm supply contracts rather than interruptible arrangements; and operating discipline that rotates maintenance through the fleet on a schedule the load never sees. The grid produces firmness through the statistical diversity of thousands of generators. A dedicated plant produces it through deliberate design.

How firmness is contracted

Engineering makes firmness possible; the contract makes it real. A firm power agreement states the capacity, defines a measurable availability guarantee, and attaches remedies with teeth when the guarantee is missed — matched by a symmetrical commitment from the buyer to pay for the capacity being held. A firmness claim without an enforceable guarantee behind it is a brochure. For how firm behind-the-meter supply compares with grid service on cost, see the cost math; for how to pressure-test a provider's firmness claims, see how to evaluate a BTM power provider.

About Corley Energy

Corley Energy is a behind-the-meter independent power producer, founded in 2024 by Jake Corley, Tim Bozeman, and Mark Meyer. We convert stranded Permian Basin natural gas into firm, contracted electricity for AI data centers at Power Foundry, our ~1,000-acre development in Upton County, Texas. Start with what a power foundry is, see the company facts, or check current capacity on the Sites page.

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