Links are to Amazon because it is easy - will shop later.
Custom, plasma cut and welded - maybe in aluminum? Roughly 18” x 18” x 3”, with all sides at about 45 degrees or a little less steep.
Solar panel mount is tough because of heat, fragility, dust. Options considered: plastic cover, potting cells, grate, vertical,
LEDs are covered in clear plastic (⅜ polycarbonate?).
Holes on the corners (or tabs) so it can be lagged down (or screwed for other orientations). Weather stripping all the way around + closing hatch on bottom so it is sealed from the elements inside.
Adding some slope (even five degrees) to the panel will help with water and dust.
LEDs: Maybe just strips of WS2811 with ip6x rating (example), stuck to an aluminum sheet inside. The COB ones look rad, but I can’t find weather proof ones. Aiming for 5-10 Watts at full bright white.
Controller: ESP32 with WLED seems like the right approach. I’m currently leaning toward an integrated version so we don’t have to deal with an enclosure, level shifter, buck down, capacitor and resistor on LED data line, etc.
Getting them to coordinate is a neat idea, and I think we can do it if we have a WiFi router (no internet needed, just network).
Alternatives: Could just go warm white if we don’t want future flexibility, but I think it is worth it. Some folks balk at working under RGB lights, they are a bit less pleasant and can cause visual distortion (multiple shadows, etc) and odd color rendering.
Maybe 12 V 10 Ah LiFePO4 battery as the core (example). A flat pack of 18650 cells would fit better perhaps.
The desired 18x18 max size limits us to 20-30 Watts of solar panel.
For the solar controller I really want MPPT, waterproof, load (capable with day/night), and LiFePO4 compatible. Haven’t found one yet!
Victron Energy SmartSolar is the best I have found (ip32 which is ok). But it is $62! It does have bluetooth, which might make debugging easier (don’t have to open the box to see charge).
Tempted to say “fuck it” and get a $27 20W panel with PWM controller - we can always upgrade later.
There’s a line of very low cost MPPT bare-board controllers from China like this one. Would need housing but could be sorted out in the integration.
Inline fuses will be added where needed - probably ought to store a spare onboard.
Solar controller: Is there an affordable solar controller that is MPTT, waterproof, LiFePO4 compatible, and has day/night load?
LED controller: What’s the best controller for the LEDs? Affordable, robust, waterproof, sync between devices, easy to update while camping.
Thermal management: Operating in full sun on the playa means internal temps could get dangerously high.
Mitigation ideas under consideration: Elevate solar panel slightly for airflow underneath, add heat sink fins, couple to earth.
Pretty worried about the plastic over solar. Maybe pot raw cells in epoxy? Go more vertical? This one is hard.
Wi-Fi sync reliability: Can WLED sync robustly in a dusty, low-signal, multi-node environment with a 12 V router?
Lighting brightness vs runtime: 5–10 W may be too high for all-night operation with one cloudy day. Need testing.
Ingress protection: Full sealing is planned, but fine playa dust may still creep in. Any need for breathable membrane or pressure relief?
Light positioning: The higher the light is, the better it illuminates things. But then it can’t be walk-over-able. Maybe two physical modes? Something that rises up optionally? Lights that are spring-loaded so they fold down when they are run over?
How deep to design for? If we require digging down 2 inches (maybe with a template) then that opens up a lot of design space.
This is a hard design space - the heat, size, price, etc. Alternatives:
Smaller, off the shelf: smaller, combo of driveway lights (or these) and yard solar lights (or these, this package is a little weird, but great reviews). The very low cost of these means we could do 10+ easily - more robust to failure.
Design: simple folded sheet that has both a yard light (flood facing art) and one of the driveway lights (ambient / safety / secondary). At $10 each we can get these super cheap. Make it laggable, open sides for ventilation (since already waterproof).
Could also do an upwash version with these. Just put 3 or 7 in a plate, lag it down.
Bigger: 100 watt panel is more economical (fewer controllers, panels are common), and also much easier for heat. Maybe a bench with lights on either end, facing the art? Solar as seat (under plex / grate), maybe some soft down lighting too.
No solar: batteries are getting way cheap. We could just go with 100 Ah of LifePO4 and have it last ten+ days. Much simpler, about the same price, more weight and volume, much less fragile and location-dependent.