Market updates
5 min
ISO-NE day-ahead ancillary services: 2025 review and upcoming reform
Winter accounted for 60% of the first full-year total, but even that understates how concentrated the cost was. Winter Storm Fern (Jan 25–29, 2026) contributed 40%, and single day (January 27, 2026) accounted for 18%. High costs are leading ISO-NE to reform the ancillary services market in Q4.9 hours ago
