NorthernLights Curtailment Analysis Service Offering

OVERVIEW

NorthernLights Advisory Services offers specialized, independent curtailment analysis to renewable and conventional energy developers, investors, lenders, and project owners. This service can be provided as a standalone deliverable or integrated into a full-scope Independent Engineer (IE) review. We deliver a rigorous, transparent, and bankable forecast of annual grid-related curtailment for your wind, solar, hybrid or conventional facility. The analysis focuses exclusively on quantifying the expected year-by-year curtailment rate due to thermal, voltage, stability, economic dispatch, and other grid constraints. A core component of the service is a detailed congestion analysis, which identifies and quantifies the contribution of specific transmission path bottlenecks (thermal overloads, stability limits, voltage collapse, etc.) to overall curtailment and shows how planned and unplanned upgrades will relieve those constraints over time.

This service is designed to:

  • Support project financing, PPA negotiations, and tax equity structuring by clearly defining long-term curtailment risk and congestion exposure

  • Provide lenders and investors with credible, defensible year-by-year curtailment estimates and congestion reduction timelines

  • Quantify the expected impact of planned, unplanned, regulatory, permitted, and procurement-stage grid upgrades on both curtailment and congestion

  • Evaluate policy risks, including the One Big Beautiful Bill Act (OBBBA), on future curtailment rates, RPS compliance, and congestion levels

SCOPE OF WORK

Our standard curtailment analysis includes:

  • An annual curtailment forecast showing the expected curtailment for each year from commercial operations

  • Congestion component analysis that breaks down curtailment by specific transmission paths and monitored elements at and around the project POI

  • Year-by-year attribution of curtailment drivers (thermal congestion, stability limits, voltage collapse, economic dispatch, etc.) and their contribution over time

  • Detailed assessment of how all relevant grid upgrades reduce both overall curtailment and specific congestion on critical paths

  • Explicit modeling of generation retirements, new build capacity, load growth, and transmission constraints and their effect on congestion and curtailment

  • OBBBA scenario analysis quantifying the incremental curtailment and congestion risk from slowed renewable deployment and delayed transmission

  • Sensitivity cases (e.g., different upgrade timelines, load growth scenarios, or storage deployment levels)

METHODOLOGY AND KEY ASSUMPTIONS

We employ a fundamentals-based engineering and economic model calibrated to the relevant utility’s production-cost tools (PLEXOS or equivalent). The model integrates:

  • Real grid topology and monitored transmission paths at the project POI

  • Historical flow patterns and actual curtailment data from Monthly Operating Reports

  • Utility-specific upgrade schedules from IRPs, Ten-Year Transmission Plans, and regulatory dockets

  • Retirements of conventional generation and their impact on available transmission capacity and congestion relief

  • Economic curtailment driven by negative pricing in EIM or island dispatch markets

  • State and federal RPS policies and their influence on regional congestion and curtailment

All assumptions are fully transparent and documented.

DELIVERABLES

  • Comprehensive Curtailment Analysis Report (PDF) with executive summary, detailed methodology, network upgrades (planned and unplanned) year-by-year curtailment tables, congestion path-specific charts, and sensitivity results

  • Excel workbook containing curtailment estimates, congestion driver breakdowns, and sensitivities

  • Optional: Professional presentation deck suitable for lenders, investors, or internal stakeholders

  • Optional: Integration package with opinion letter for full-scope IE review