Physical-damage model

Purpose

The physical-damage model estimates how much physical damage natural hazards cause to a plant each year, on average and in severe years.

Inputs

Hazard	Input data
Hail	NOAA MRMS radar hail estimates, checked against storm reports.
Convective wind	ASCE 7-22 wind maps and NOAA tornado paths since 1996.
Hurricane	STORM synthetic tropical-cyclone data.
Wildfire	USDA Forest Service FSim burn probability and flame-length simulations.
Flood	Flood mapping and National Water Model flows, Atlas 14 rainfall, elevation data and SLOSH surge.

For all data sources, see Data sources and validation.

Method

The model converts hazard events into damage to the benchmark asset. Then it summarizes the losses across simulated years.

1. Hazard: estimate the frequency and intensity of events in the grid cell.
2. Reach: find whether an event reaches the plant’s footprint.
3. Damage: apply damage curves for the technology to estimate the fraction of plant value lost.
4. Annual loss: add the event losses in each simulated year.

For each asset, the model adds the losses from all hazards in each simulated year. Then it reads the severe-loss measures from those combined annual losses. It does not add the separate hazard percentiles.

Grid resolution. The reference grid uses quarter-degree cells. Some source data are finer: about 1 km for radar hail and 270 m for wildfire. For hail, the model samples several plant positions in a cell and averages the results. Fine source data do not make the benchmark an exact-site estimate.

Outputs

Output	Summary
EAL	The average annual loss across simulated years.
Hazard Loss	EAL divided by asset value.
PML	The loss at the selected return period, read from the loss-exceedance curve.
Climate VaR	The P95 annual loss, read from the loss-exceedance curve.
Expected Total Annual Loss	EAL plus Forced Outage Loss and Recovery Loss.

For units and aggregation, see the Metrics dictionary.

Assumptions

• The model calculates losses for the standard benchmark asset, then scales dollar values to the asset’s capacity. See Benchmark and asset-specific results.
• Asset value is the benchmark asset value, scaled to capacity.

Limitations

• A cell represents an area, not the exact footprint of the plant.
• Wind assets include convective wind and hurricane only. A hazard that is not modeled is not zero risk.
• Total Climate VaR adds asset P95 losses. It does not model how losses at different sites move together.

For all limitations, see Limitations.

Validation

See Validation checks.

Version

Applies to methodology version 1.0, September 2026.