Project Hail Mary — Solar Panel Simulator

User input Computed output Measured data

Incident angle (°) 0°

0° normal incidence90° grazing

Light intensity (%) 82%

0% — dark100% — full sun

Environmental inputs

Sub-panel blocking — click cells to block

Observed: any blocked cell kills the entire sub-panel branch. Other 3 branches unaffected. 0° = panel normal pointing directly at sun/light source (empirically found as max power position).

Panel power output

Total power

—W

0 W—180 W max

Front side · 160–180 W max at 0°, clear sky

Bus voltage

—

Total current

—

% of max

—

Power loss breakdown

Angle loss

0 W

Intensity loss

0 W

Shading loss

0 W

Output

0 W

Internal circuit — 4 sub-panels in parallel

Power vs. incident angle — polynomial fit per trial

Predicted (poly, all trials combined) May 4 — Trial 1 (10:24 AM) May 5 — Trial 1 May 5 — Trial 2 May 9 — Trial 1 May 9 — Trial 2 May 9 — Trial 3

Normalized power vs. incident angle — P(θ) / P(0°)

cos(θ) reference Poly fit (normalized) May 4 — Trial 1 May 5 — Trial 1 May 5 — Trial 2 May 9 — Trial 1 May 9 — Trial 2 May 9 — Trial 3

Time of day simulator — Seattle, WA · May 9, 2026 · panel lying flat

Time of day 12:00 PM

6:00 AM sunrise8:30 PM sunset

Note: this models the panel lying flat (horizontal), so incident angle = 90° − solar elevation. This is not how our experiment was set up, it's a reference showing how a fixed flat panel would perform throughout the day in Seattle.

Solar angle

—

Est. power

—

Incident angle

—

Measured vs. predicted — all runs

Incident angle	Measured (W)	Measured (V)	Poly pred.	Poly err.

EcoFlow EF-Flex-220B — from manual

Rated power (STC)	220 W ±5 W
Real-world max (front, 0°)	180 W
Open circuit voltage Voc	21.8 V
Max power voltage Vmp	18.4 V
Short circuit current Isc (STC)	13.0 A
Max power current Imp (STC)	12.0 A
Operating Imp (180W ÷ 18.4V)	~9.78 A total
Per sub-panel operating Imp	~2.45 A each
Power temp. coeff.	-0.39 %/K

Simulator built with assistance from Claude (Anthropic)