The heat that rolled through California and the Desert Southwest brought with it the highest peak demand of the spring (2025) where CAISO displayed a level north of 32.0 GW as the actual volume topped that of the day-ahead forecast. The figure below displays the level mentioned where the rightmost graph breaks down each balancing region where SCE was the one that escalated with the above-normal temperatures in play throughout the LA Basin.

Figure 1 | CAISO Peak Demand Breakdown – Actual and Forecast

The increase in demand was in full display throughout the entire day, including the midday period where the marginal cost of energy remained in positive territory thus reducing any sort of curtailment volume.  Positive price levels in the midday period also begs the question of how did the battery fleet hourly charge and discharge profile get altered as the lack of negative prices need the evening ramp to perform at a higher level to keep the margin at a level that is enticing for the flexible resource?  The results are broken down in the following sections.