Quantifying the 2021 Texas Freeze with Satellite Econometrics

In February 2021, Winter Storm Uri descended on Texas, triggering one of the most catastrophic infrastructure failures in modern American history. Temperatures plunged, demand spiked, and the state’s isolated power grid—operated by ERCOT—collapsed. Millions lost power for days.

While utility companies provided their own outage estimates, we can use remote sensing to independently verify the scale of the economic damage. Using Python, Google Earth Engine, and the Difference-in-Differences (DiD) framework, we analyzed the blackout from space.

The Natural Experiment: A Tale of Two Grids

To measure the true impact of the grid failure, we cannot simply look at Houston in isolation. We need a control group—a city that faced the same freezing temperatures but did not lose power.

Enter El Paso. Unlike the rest of Texas, El Paso is not on the ERCOT grid; it is connected to the Western Interconnection. This creates a perfect "Natural Experiment":

• Treatment Group: Harris County (Houston) – ERCOT Grid (Failed).
• Control Group: El Paso County – Western Grid (Functional).

Visualizing the Shock

We utilized VIIRS Nighttime Lights data, which measures the radiance of light emissions from Earth. By comparing the monthly trends, we can see the "Parallel Trends" leading up to the disaster.

Figure 2: Spatial Analysis & Economic Impact. Left: El Paso (Control) shows stability. Right: Houston (Treatment) shows widespread power loss (Blue areas).

The Economic Toll

Our regression model confirmed a 20.37% drop in monthly radiance for Houston. But what does that mean in dollars?

Converting light loss to economic loss is a challenge, but we applied two standard econometric methods to estimate the damage:

Metric	Methodology	Est. Loss (Houston)
Business Interruption	Light-to-GDP Elasticity (1:1)	~$7.6 Billion
Welfare Loss	Value of Lost Load ($9,000/MWh)	~$15.8 Billion

Key Finding:
A 20% monthly drop in light implies a near-total blackout for the 5-day duration of the storm. While satellites capture the immediate grid failure cost, they likely underestimate the total damage (estimated at >$80B) because they cannot see internal physical destruction, such as burst pipes.

Appendix: Deriving the Damage

The estimates above are derived directly from the regression coefficients and Harris County economic data. Here is the step-by-step math:

1. The Radiance Drop

We first calculate the percentage of light lost by dividing the "Shock" (DiD Coefficient) by the "Baseline" (Intercept + Natural Difference).

Formula % Drop = | DiD Coefficient / (Intercept + Treat) |

Calculation % Drop = | -6.83 / (9.30 + 24.23) |
% Drop = 0.2037 (20.37%)

2. Business Interruption (GDP)

Using the Henderson Method, we assume a 1:1 elasticity between light loss and GDP loss for acute disasters.

Formula Loss = (Annual GDP / 12) × % Drop × Elasticity

Calculation Loss = ($450 Billion / 12) × 0.2037 × 1.0
Loss = $37.5 Billion × 0.2037
Loss = $7.64 Billion

3. Welfare Loss (VOLL)

Using the "Value of Lost Load," we calculate the social cost of the unserved energy at the price cap set by ERCOT ($9,000/MWh).

Formula Loss = (Avg Load × Hours in Feb) × % Drop × Price Cap

Calculation Total Energy = 12,000 MW × 672 Hours = 8,064,000 MWh
Lost Energy = 8,064,000 × 0.2037 = 1,642,636 MWh
Loss = 1,642,636 × $9,000
Loss = $14.78 Billion

Analysis generated using Google Earth Engine & Python.