State advisory group outlines framework to ‘decarbonize the peak’ and assess peaker plants and CHP alternatives

A Focus Area Working Group update summarized phase 1 findings on decarbonizing winter and summer peak demand by examining the role of peaker plants and combined heat and power (CHP) facilities and by outlining a two-track assessment across four demonstration sites.

Presenters said peaker plants—defined by the working group as dispatchable thermal resources operating less than 50% of the time—supply a disproportionate share of capacity relative to their annual energy contribution. The group noted an illustrative finding: in some hours the region’s peakers supply a large share of capacity while contributing only about 10% of annual energy, reflecting low capacity factors. The group also flagged that peaker plants can be among the most expensive resources during the top-cost hours in ISO New England.

CHP facilities raise distinct challenges because they deliver both thermal and electrical services; decarbonizing those installations requires replacing thermal loads as well as electricity, which can shift peak demand patterns. The group stressed that the viability of alternatives depends on site-specific conditions (interconnection capacity, land availability, load profile, and community impacts) and system-level factors (renewable penetration, storage, transmission build-out).

Methodology and next steps: the group described use of resource adequacy metrics, such as effective load-carrying capability (ELCC), to compare resources’ contribution to reliability. Phase 2 will evaluate supply-side and demand-side alternatives—renewables, storage, energy efficiency, demand response, transmission upgrades—using a rubric that combines reliability, cost, greenhouse‑gas impact and timing. The working group will move from conceptual frameworks to an assessment phase that applies the rubric to four demonstration facilities (identified in the meeting as site case studies) and will report back with assessment results.

Why this matters: the working group is attempting to reconcile two forces: increasing renewable generation and growing electrification that can change the timing and magnitude of system peaks. The project aims to produce options that reduce greenhouse-gas emissions from peakers while preserving grid reliability.

Ending: The advisory board will review the assessment rubric and early results at future meetings; presenters asked participants to consider demand projections and scenario ranges (higher electrification, higher renewable penetration) when evaluating alternatives.