Batteries make their money on the gap — the daily distance between the cheapest hours to charge and the priciest hours to discharge, plus whatever the grid will pay to hold capacity in reserve. Heading into the back half of June 2026, both of those revenue lines are running thinner than they were a year ago. Real-time arbitrage spreads have compressed sharply against June 2025, regulation-up is printing a fraction of its prior-year level, and the dispatch chart shows why the easy money is getting harder to find: there are simply more batteries chasing the same shape. This note walks through three slices of the Energy GPS ERCOT Battery Dashboard — the TB arbitrage table (Figure 1), regulation-up pricing (Figure 2), and the storage dispatch profiles (Figure 6). Unless noted, arbitrage values are real-time TBNth spreads in $/MWh and ancillary prices are in $/MW; a TB2 value is the average of the two best buy/sell hour pairs in a day, TB4 the best four.

1. Arbitrage Spreads: A Step Down Year-on-Year

Figure 1 frames the arbitrage picture three ways: last year’s monthly average (Jun-25), the prior month (May-26), and the current month to date (Jun-26). The headline is the year-over-year column. Across all four hubs, the TB2 spread — the richest two-hour swing of the day — sits 31% to 45% below where it printed last June. Houston leads the descent: its TB2 average has fallen to $38.31/MWh in June 2026 from $69.34 a year ago, a drop of better than $31, while the broader TB4 average eased to $30.42 from $46.77. West, North, and South tell the same story in slightly gentler tones, with TB2 spreads landing in the $34–$43 range against year-ago marks in the high-$50s to low-$60s.

The month-on-month read is far less dramatic, which is the more important point. Against May, Houston’s TB2 is essentially flat (up a few cents) and its TB4 is off about a dollar; West, North, and South each slipped a more meaningful 7% to 11%. In other words, the spread compression is not a sudden June event — it is a level shift that was already largely in place by spring and has simply held. Batteries are still capturing a positive spread every day, but the ceiling on that spread has come down and stayed down.

Table 1 | TBNth real-time arbitrage values by hub ($/MWh) – TB2 and TB4 daily averages, with month-on-month and year-over-year change

ERCOT’s evening ramp power prices are set, hour by hour, off the marginal gas-fired unit, so the height of the daily peak scales with the price of gas at the burner tip. Through June 2026, Houston Ship Channel cash has matched that of June 2025 where both months are averaging just under $3.00/MMBtu. When gas is cheap, the absolute dollar gap between the cheap hours and the expensive hours narrows, because the expensive hours are no longer being lifted by expensive marginal fuel. In June 2026, the market fundamentals around the supply and demand elements are driving the arbitrage opportunity for batteries lower as Houston Ship Channel gas is neutralized. The recent uptick in Texas heat has put a little life back into the daily prints — note Houston’s $56.65 TB1st on June 18 — but the monthly average is still anchored well below 2025.

2. Regulation-Up: Cheaper Than It Has Been in Years

If the energy spread has stepped down, the ancillary stack has fallen off a ledge. Regulation-up (RegUp) has averaged just $1.16/MW month to date in June 2026, against $1.69 in May and $3.03 last June — a year-over-year decline of roughly 62%. The daily series tells the same story with the volatility intact: RegUp touched $2.07/MW on June 15 and $2.04 on June 19 when the grid tightened but spent most of the week closer to $0.70–$1.00, ending at $0.78 on June 21. This is not a one-month dip. June 2026 RegUp is coming in well below both past two years, the continuation of a multi-year slide as ERCOT’s fast-responding battery fleet has steadily saturated the regulation and responsive-reserve markets it once found so lucrative.

Table 2 | ERCOT ancillary prices ($/MW) – monthly averages with the latest weekly RegUp prints

The logic is the same supply-and-demand story that compressed the energy spread, just turned up a notch. Regulation and responsive reserve are exactly the products batteries are best at — near-instant, precise, and cheap to provide once the asset is built. As more megawatts of storage have come online and bid into those markets, the clearing price for the service has been competed down toward the cost of providing it. RegUp at barely a third of its year-ago level, and RRS off some 80%, is what a maturing, increasingly battery-dense market looks like. The lone exception in the stack is Non-Spin, which actually firmed year-on-year — a reminder that the slower, energy-heavy reserve products are less directly in the batteries’ wheelhouse and have held their value better.

3. The Dispatch Profile: More Batteries, Bigger Swings

Figure 6 shows where all of this comes from. The daily panel plots the last seven days of ERCOT battery dispatch — charging below the zero line, discharging above it — against the average real-time hub price. The choreography is textbook arbitrage: the fleet charges hard through the low-price overnight and midday-solar hours, then swings to full discharge into the evening price ramp. Discharge peaks line up almost exactly with the red price line, and the single largest discharge of the week sits under the sharpest price spike, near June 19, when average real-time prices pushed toward the $80s. On a typical day the fleet swings from roughly 5,000–7,000 MW of charging to a comparable burst of discharge — a clean, repeatable buy-low, sell-high pattern that is the bread and butter of the value streams in Sections 1 and 2.

Figure 1 | Daily power storage, last 7 days – battery charge and discharge (MW) against average real-time hub price ($/MWh)

Stretch the lens out to the year-over-year view and the structural shift jumps off the page. The 12x24 profile lays each year’s hourly net-output shape side by side, and 2026 (blue) dwarfs both 2025 (orange) and 2024 (red) through the first half of the year. Where the 2024 fleet barely registered — net swings of a few hundred megawatts — the 2026 fleet is driving troughs toward 4,000 MW and discharge peaks near 6,000 MW in the same months. Each year the amplitude of the daily cycle widens as more storage capacity is installed and dispatched. That is the crux of the whole note: the fleet is moving far more energy than it did a year or two ago, but it is doing so into thinner spreads and cheaper ancillary prices. Higher volume, lower margins.

Figure 2 | Energy storage net output, 12x24 hourly profile (MW) – 2026 vs. 2025 vs. 2024

The Bottom Line

One market, two forces, the same direction. Natural gas keeps a lid on the peak-to-trough power spreads that drive TB arbitrage, while a fast-growing battery fleet is competing down the regulation and reserve prices that used to pad the returns. The result is a June 2026 that has batteries running more cycles and moving more megawatt-hours than ever — yet earning less per unit of work on both the energy and ancillary sides than they did a year ago.

The swing factor heading into Q3 will be weather. The recent Texas heat has already nudged the daily arbitrage prints higher; a sustained run of triple-digit afternoons would widen the spreads and put a bid back under RegUp on the tightest days. But absent that, the trend is clear: as the fleet scales, the value per megawatt thins, and the operators who win will be the ones squeezing the most out of an increasingly crowded, increasingly efficient market. For more information on the Energy GSP Market Analytics Enterprise, Subscription or stand alon Battery product offerings, one can email us using the Contact Us form on the Energy GPS website or at [email protected]. 

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