This past weekend in ERCOT, real-time prices stayed under $0/MWh for several hours. An overabundance of wind and solar led to prices as low as -$30/MWh and several gigawatts of renewable curtailments. At first glance, it seems like a great opportunity for ERCOT batteries to charge at very cheap prices. The figure below is featured in ERCOT Daily Battery Dashboard and displays the potential real-time arbitrage opportunities for 2-hour batteries in ERCOT if they picked the best possible charging and discharging hours. This last weekend, the 4^th and the 5^th, had some of the highest arbitrage opportunities so far this month. The TB2 average ranged between $47 – 59/MWh across the hubs. For the Houston, North, and South hubs, many of the other days displayed saw TB2 averages below $30/MWh. However, the reality of the timing of the low prices made it hard for batteries to capture. In this battery report, we’ll dig deeper into the fleet’s response to real-time prices this weekend and over time.

Table 1 | TBNth RT Arbitrage Values ($/MWh)