CALCULATORS / SOLAR AND RENEWABLE ENERGY

Solar-panel orientation screening calculator

Direct-beam incidence cosine only; diffuse irradiance and shading omitted.

solar-panel-angle.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

This source describes an analytical model. Its quantities and checks are the view.

Scenario	powerW
	277.128
	221.703

All calculated quantities are listed with the inputs. Switch to Source to inspect the equations.

SCENARIOS / CALCULATED VALUESSAME SOURCE

Change an input to see the consequences.

power target277.13 W✓ passes

BASELINE INPUTS

irradiance800 W/m^2incidence30 degarea2 m^2efficiency0.2

CALCULATED

power277.13 W

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Solar-panel orientation screening
# Scope: Direct-beam incidence cosine only; diffuse irradiance and shading omitted.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

irradiance = 800 W/m^2
incidence = 30 deg
area = 2 m^2
efficiency = 0.2

power := irradiance*max(0,cos(incidence))*area*efficiency [W]

check power target: power >= 200 W

scenario alternative: irradiance = 640 W/m^2

Calculated from your source · not saved

Baseline · Baseline

power target277.13 W ✓ passes

alternative · alternative

power target221.70 W ✓ passes

Illustrative first-order example. Checks are editable requirements, not design standards. The broader topic may require additional equations, data, and validation.

Formula and units

This example uses the following equations. Input names and units match the editable source above.

power: power = irradiance*max(0,cos(incidence))*area*efficiency [W]

Original worked example

These are the baseline values in the downloadable source. Edits above let you test your own values.

Given

irradiance: 800 W/m^2
incidence: 30 deg
area: 2 m^2
efficiency: 0.2

Calculated

power: 277.128 W

Assumptions and limits

Direct-beam incidence cosine only; diffuse irradiance and shading omitted.

The requirement checks use the limits written in this example. Passing a check does not establish that the model covers every load, material behavior, or operating condition in a real design.

Download this .napkin example ↓

Take it further with your agent

Napkin keeps the inputs, equations, checks and assumptions together in one study. Your agent sets it up; you change the numbers.

Try with Claude ↗

codex 'Use Napkin (https://napkin.engineering/mcp, or the local Napkin plugin) to build a study: Solar-panel orientation screening. Inputs: latitude; date/time; surface tilt and azimuth. Outputs: incidence geometry; relative exposure. Model scope: Location/weather inputs or explicitly selected irradiation assumptions. Read napkin_capabilities and the current snapshot. Ask me for the values that matter, label assumptions with units, author .napkin source, validate it and apply it with napkin_source using the current revision, then open the study. Add checks for the limits I supply. Keep unsupported analyses explicit.'

Claude needs the Napkin connector; Codex needs the Napkin plugin. Set up your agent ↗

The broader study

The topic brief below describes the broader scope. The worked example above states the particular calculation it implements.

Inputs: latitude, date/time, surface tilt and azimuth
Outputs: incidence geometry, relative exposure
Modes: calculate, compare, sweep
Drawing: Energy and resource plots

EXECUTABLE WORKED EXAMPLE · FIRST-ORDER MODEL · CHECK THE SCOPE & ASSUMPTIONS