Merchant Power

Imagine a farmer who has two ways to sell his vegetables. He can sign a year long contract with a hotel that buys a fixed quantity at a fixed price every single day, rain or shine. Or he can carry his produce to the daily mandi and sell it to whoever is bidding highest that morning, accepting that some days the price is excellent and some days it barely covers his costs. A power plant faces the exact same choice, and merchant power is the mandi option.

Most power in India is sold under a Power Purchase Agreement, a long term contract where a state distribution company agrees in advance to buy a fixed quantity of electricity at a fixed or formula based tariff, often for twenty five years. It is predictable for both sides. Merchant power is what a generator sells instead, or in addition, on the open power exchanges such as the Indian Energy Exchange, without any long term buyer locked in. The price is discovered fresh every single day, sometimes every fifteen minutes, based on who needs power right now and who has spare capacity to sell.

Generators keep a merchant capacity for a simple reason. When a heatwave or a festival season pushes demand well above what long term PPAs cover, spot prices on the exchange can spike far above regular tariffs, and a plant with uncommitted capacity captures that upside directly. The tradeoff is that on a mild, low demand day, the same plant might sell power at a price barely covering fuel cost, or choose not to run at all.

This is why merchant power is inherently a higher risk, higher reward business than a PPA backed plant, and why lenders price merchant heavy generators differently from those with long term contracted revenue. Companies like JSW Energy and Adani Power have historically carried a mix of both, using contracted capacity for stability and merchant capacity to capture upside during tight grid conditions, particularly during the peak summer months when demand routinely outstrips supply in several states.

Whenever a power stock rallies sharply on news of a heatwave or a surge in exchange prices, it is almost always the merchant portion of that company's capacity doing the work, not its contracted base.