SolXY

SolXY is a 3D simulator for planning rooftop solar panel installations. Build
your roof in the app, place panels on any slope, and see exactly when and
where the sun reaches them — hour by hour, all year round.

Designed for the moment before you commit to a solar installer's quote:
when nearby buildings cast shadows that limit which roof slopes will
actually produce power. SolXY shows you the answer in 3D, on your device,
in a few minutes.

WHAT YOU CAN DO

• Build your home in 3D. Set width, depth, height, and pick from 7 roof
types: flat, gable, hip, gambrel, skillion, saltbox, butterfly.
• Add the garage, the neighbour's house, and any other building that
might cast a shadow. Shadow-casters don't need panels — they just
affect the sun calculation.
• Place a solar panel array on any roof slope. Configure panel size,
rows × columns, gaps, position offsets, and a mounting lift for
scaffolding setups.
• Set tilt, roll, and yaw to match how the panels are mounted, or
enable sun-tracking to see what a tracking installation would do.
• Scrub date and hour sliders to watch shadows move across the roof
through the day and through the year.
• Compute an annual energy yield estimate based on your panel rating,
system derate, tilt, and the simulated shading.
• Save and load scene configurations as JSON for sharing or backing
up your design.

SOLAR PHYSICS YOU CAN INSPECT

• Real sun position computed from latitude, longitude, and time.
• Annual solar paths shown as arcs around your scene.
• Per-panel sun rays toggle showing which panels are catching direct
sunlight at each moment.
• Yearly shading heatmap raycasting hundreds of timestamps against
~0.4 m cells of each roof slope to colour-code total annual sun
received — green where it's clear, red where it's blocked.

PRIVATE BY DEFAULT

• No account. No sign-in. No analytics. No advertising.
• Everything runs on your device. Your location, building dimensions,
and panel layouts are stored only in local storage and never leave
your phone.
• Network access (Android's INTERNET permission) is used only to load
the bundled offline assets — nothing about your design or location
is transmitted.

INTERACTIVE TUTORIAL

A first-run coachmark tour walks you through every group of controls so
you know exactly what each setting does. Replayable from Settings any
time.

LIMITS YOU SHOULD KNOW

• The default yield estimate uses an analytical clear-sky model, which
tends to over-estimate annual production by 10–25 % compared to real
climate data. Treat the kWh figure as an upper bound, not a quote.
• SolXY is a planning aid, not an engineering calculator. Always
confirm structural, electrical, and regulatory aspects of your
installation with a qualified solar installer in your area.