In 2024, New York and Massachusetts recorded more than 2,600 wildfires, more than double the prior year. Wildfire risk is no longer a West Coast problem. The Northeast exposure is wind-driven and concentrated at the suburban-wildland interface, where vegetation density and building density converge with aging overhead infrastructure.

With National Grid serving more than 20 million people across its electric and gas networks in New York and Massachusetts, the operational question wasn't whether to act — it was where. National Grid already had strong vegetation management and infrastructure programs in place. What they needed was asset-level risk quantification: a way to separate high-consequence feeders and spans from negligible-risk ones across thousands of feeders and tens of thousands of miles of conductor.

Rhizome deployed gridFIRM across National Grid's Massachusetts and New York service territories, encompassing over 3,400 distribution feeders, nearly 1.5 million poles, roughly 590,000 transformers, and over 1.1 million overhead conductor segments.

The risk modeling framework was built from first principles for the Northeast context, not adapted from West Coast wildfire models. Rhizome evaluated how asset failure probability, ignition likelihood, and fire consequence interact in a region defined by wind-driven fire weather, dense suburban-wildland interfaces, and aging overhead distribution infrastructure. The framework draws on established industry methods and was calibrated against National Grid's own outage history, ensuring the model reflects how this specific system actually behaves under fire-favorable conditions rather than relying on assumptions built for different geographies. The result is a risk framework purpose-built for the Northeast.

The analysis quantified wildfire risk as the product of three components: the frequency of outage events during fire-favorable weather conditions, asset-specific ignition characteristics (such as feeder configuration and conductor insulation), and the potential consequences of wildfire spread. The consequence layer incorporated vegetation and landscape conditions that affect fire behavior, fire weather severity, and population and building density near each asset.

Rhizome integrated 17 years of historical outage records with high-resolution weather modeling, asset inventory data, and environmental consequence layers. Data-calibrated fragility curves modeled how asset failure probability shifts under varying wind and precipitation conditions. Future climate projections through the 2080s, under both moderate and high-emissions scenarios, extended the analysis past the historical record. The assessment also included a dedicated transmission analysis and an egress risk evaluation identifying neighborhoods with limited evacuation routes.

All results were delivered through gridFIRM, where National Grid's engineering and climate teams can explore risk from system-wide rankings down to individual poles and conductor spans.

• Risk is extraordinarily concentrated. In New York, 1% of feeders account for 35% of total system-wide wildfire risk, which means National Grid can direct mitigation efforts toward the feeders where the impact is highest.

‍

• Distribution, not transmission, is where the risk lives. Transmission infrastructure contributes a small fraction of system-wide wildfire risk. The distribution system accounts for the vast majority of ignition potential because of its greater exposure to vegetation contact, lower clearances, and sheer density of overhead assets.

‍

• Even within high-risk feeders, risk clusters in a handful of spans. On one representative feeder, just 25 conductor spans (about 4% of total feeder length) accounted for 35% of that feeder's wildfire risk. That level of granularity makes it possible to replace or harden specific poles, conductor segments, and transformers rather than upgrading entire circuits.

National Grid now has an asset-level wildfire risk baseline across its full Massachusetts and New York service territories. 

With risk quantified down to individual conductor spans, National Grid can evaluate system decisions related to wildfire risk down to the feeders and spans where it matters most. Climate projections through the 2080s are built into the model, so those decision priorities hold up over time. National Grid also asked Rhizome to evaluate egress risk, flagging areas where wildfire risk coincides with limited evacuation routes and adding context to mitigation planning. 

Following deployment in the United States, National Grid is extending gridFIRM to its operations in the United Kingdom. Across these geographies, the risk baseline gives National Grid a foundation to measure mitigation impact over time and adjust priorities as conditions change.