Market monitor issues spring 2026 quarterly report

Even as natural gas prices dropped this spring, emissions costs and other factors drove an increase in wholesale electricity costs, according to the latest quarterly report from ISO New England’s Internal Market Monitor (IMM).

The Spring 2026 Quarterly Markets Report, which covers the period from March 1 to May 31, presents an assessment of each of the region’s wholesale electricity markets, based on market data, performance criteria, and independent studies.

Natural gas prices averaged $2.79 per million British thermal units in spring 2026, the IMM said. That’s 18% lower than the previous spring and significantly below the average for the winter of 2025/2026. Natural gas is the predominant energy fuel in New England, and wholesale electricity prices usually are closely linked to natural gas prices.

However, emissions-related costs rose 65% year over year for a typical natural gas generator. These elevated prices reflect tightening emissions caps under the Regional Greenhouse Gas Initiative and Massachusetts Electric Generator Emissions Limits coinciding with higher emissions during a period of extreme cold over the winter.

Additionally, the share of supply from nuclear resources decreased due to refueling outages, meaning less-efficient generators set energy prices more of the time. A period of unseasonably warm temperatures in mid-May also drove electricity demand up 2% compared to spring 2025.

Other key findings include:

• The total estimated wholesale market cost of electricity for spring 2026 was $1.75 billion, up 6% from spring 2025.
• Energy costs totaled $1.46 billion, up 16% from spring 2025 costs. Day-ahead energy prices, including Forecast Energy Reserve prices, averaged $48.41 per megawatt-hour (MWh). The real-time energy price averaged $47.54/MWh.
• Net imports accounted for 13% of the region’s energy supply in spring 2026, compared to 7% the previous spring.
• Capacity costs totaled $266 million, down 26% year over year as a result of lower cleared capacity and less price separation in import-constrained zones.