Equinor's 100 MW Texas battery shows the merchant model's blind spot: who pays when the grid needs it most

Equinor announced this week that Citrus Flatts Energy Center, a 100 MW/200 MWh battery in Harlingen, Texas, has begun commercial operations under East Point Energy, its wholly owned subsidiary.^[1] It is Equinor's largest US battery storage project to date, and the fifth the company has placed into service in four years.^[3] The facility will operate on a fully merchant basis in the ERCOT power market, meaning it has no long-term utility contract; instead, it will earn money by arbitraging price spreads, buying cheap electricity and selling when prices spike, and offering ancillary grid services.^[1]

This is the dominant model for utility-scale storage in competitive markets, and it works. Merchant batteries do capture value from volatility, and that arbitrage has real economic signal: it incentivizes storage to sit where price swings are widest and to charge when prices bottom. But the merchant model has a structural flaw that shows up most clearly under grid stress. A merchant battery will discharge to maximize profit, not to guarantee supply when the grid needs it most. In ERCOT's case, that blindness matters. Texas has been adding solar at historic pace (EIA forecasts 78 billion kilowatt-hours in 2026, beating coal for the first time^[1]) and battery storage to match. But the grid's peak demand now often arrives when solar output is falling and battery economics are least attractive: the late evening. A merchant battery is under no obligation to hold charge for that window. It will discharge when profitable. When grid stress and profitability align, the battery will be there; when they diverge, it will not.

The economics are clear enough: Citrus Flatts, rated at 2 hours of full discharge, stores 200 MWh. Valued at current merchant-battery yields in ERCOT (typically $20,000 to $35,000 per MW per year in capacity revenue plus arbitrage margin), the project might generate $2 million to $3.5 million annually in capacity and trading income. That is a real revenue stream, and it justifies the capital. But it assumes markets price the service the grid actually needs. They often do not. When ERCOT called emergency procedures during the 2021 winter crisis, batteries had no contractual obligation to discharge; some held back to preserve their own financial position. No law requires Equinor's battery to prioritize grid emergency over merchant profit. The facility was not designed to do so, and its contract structure gives it no reason to.

Texas could alter this calculus. ERCOT could establish a long-term bilateral contract tier, akin to the capacity market auctions in California (CAISO) or the ISO-NE Forward Capacity Market, where developers bid to provide guaranteed discharge during peak periods or emergencies in exchange for fixed per-kW-year capacity payments. That model locks in reliability while still allowing arbitrage in off-peak hours. Alternatively, ERCOT could tighten the rules for emergency reserve discharge: require that a battery maintain a minimum reserve (say, 25 percent of rated capacity) available at all times, and compensate developers for that foregone arbitrage. Neither is radical; both are standard in better-insulated markets.

For now, Citrus Flatts will chase the spread. Equinor will use its trading subsidiary, Danske Commodities, to optimize the portfolio across markets and hours.^[1] That is smart business. But it leaves the grid betting that merchant profit and grid reliability will align when it counts. In ERCOT, under Texas heat and peak load, that bet has failed before.