Short answer: Somfy sells two solar routes for blinds. The WireFree Li-ion Solar Panel Kit (9027294) mounts inside the window and keeps a Somfy Li-ion WireFree motor or the 9021217 battery pack charged, one panel per shade. The Simu AutoSun kit (2009607) boxes a 6 Nm motor, battery and solar panel together for exterior solar screens and interior shades.
A solar panel on a Somfy shade does one job. It tops up a battery so the owner skips the ladder trip with a charger. The panel has to match the battery behind it, though, and Somfy builds two separate systems for that. This guide covers the motors each one charges, the window rules Somfy prints for panel placement, and the parts that finish the job.
The two Somfy solar systems side by side
The Somfy WireFree Li-ion Solar Panel Kit (9027294) adds solar charging to a WireFree shade you already own or are building. Somfy launched it to its fabricator network in March 2022 and opened it to North American homeowners in February 2023 as a DIY purchase. It charges a lithium-ion cell, either inside the motor tube or in an external pack.
The Somfy Simu T3.5 ESP Hz 6Nm 18rpm 12V DC AutoSun Kit (2009607) is a complete motor system. Somfy lists it as "T3.5 ESP Hz 6Nm 18rpm 12V DC KIT (Includes battery and solar panel)", with a NiMH battery doing the storage.
| Part | WireFree Li-ion Solar Panel Kit (9027294) / AutoSun T3.5 kit (2009607) |
| Kit contents | Panel, mounting brackets with screws, glass mount adhesive with alcohol swab / Motor, battery and solar panel |
| Battery it charges | Li-ion, inside the motor or in the 9021217 pack / 2.2 Ah NiMH AutoSun battery |
| Motor | Your Somfy WireFree motor, bought separately / T3.5, 6 Nm (53.1 in-lb) at 18 rpm |
| Somfy applications | Interior shades and blinds, panel inside the window / Exterior solar screens and interior window coverings |
| Radio | Whatever the motor carries, RTS or Zigbee / Simu Hz, 433.420 MHz, 492.15 ft open field |
| Warranty | 5 years / 5 years |
Pick the WireFree kit for an interior roller, cellular or tilt blind that already runs on a Somfy Li-ion motor, or one you plan to build that way. Pick AutoSun for an exterior solar screen with no power at the opening.
Motors the WireFree Li-ion panel charges
Somfy publishes the compatible list on the kit's own product page, and it splits into two groups. Motors with the Li-ion cell built into the tube take the panel cable direct. Somfy's solar brochure lists these RTS references:
- Somfy Sonesse 40 WireFree RTS (Li-ion) (1240485)
- Somfy Sonesse ULTRA 30 WireFree RTS (Li-ion) (1003310), on units manufactured after March 2020
- Somfy Roll Up 28 WireFree RTS V2 (Li-ion) (1241150)
- Sonesse 28 WireFree RTS (Li-ion) (1003297), also on units built after March 2020, and Roll Up 24 WireFree RTS (Li-ion) (1240278)
External-battery motors draw from a separate pack, and the panel charges that pack. Somfy's list covers the Somfy Roll Up 28 WireFree RTS V2 (External Battery) (1241162), the Cord Lift WireFree CL32 RTS (1002422), the Cord Lift WireFree TLW25 RTS (1003294) and the Tilt 50 WireFree Through-Shaft RTS (1240276). Each of those runs from the Somfy Rechargeable Lithium-ion Battery Pack (9021217).
Zigbee owners are covered too. Somfy's somfypro catalog adds the Sonesse ULTRA 30 WireFree Zigbee (Li-ion), the Sonesse 28 WireFree Zigbee in both battery styles, and the Zigbee versions of the TLW25 cord lift and Tilt 50. The panel feeds the battery. The radio makes no difference to it.
One generation note matters. Somfy's WireFree power supply compatibility matrix pairs the original WF Li-ion Solar Panel with the 9021217 pack. Somfy's newer Li-ion 2 battery packs take their own Li-ion 2 Solar Panel, and the matrix marks the two as not compatible with each other. Read the battery part number before you order a panel.
Window placement rules from Somfy's solar brochure
A panel in shade charges nothing. Somfy's WireFree Li-ion Solar Panel brochure sets the conditions:
- The panel needs direct sunlight, and that sunlight has to pass through the window opening.
- Mount the panel on the inside of the window only.
- Use one panel per motorized window covering.
- East, south and west-facing windows get more sun exposure.
- Remove window tint from the area behind the panel.
- Check for overhangs, deep eaves, awnings, insect screens, large trees and nearby high-rise buildings that block the glass.
A north-facing window under a deep porch roof fails most of that list. Plan a plug-in charger for that shade instead, and save the panel for the sunny elevations. Somfy also publishes a worksheet, the WF Li-ion Solar Panel Checklist, in the kit's document set on somfypro.com. Run it per window before you buy.
Installing the WireFree panel kit
Somfy describes the kit as plug and play, with no electrician needed. The box carries the panel, brackets with screws, and glass mount adhesive with an alcohol swab for prepping the glass. The panel cable connects to the motor's charge port or to the 9021217 pack, depending on the motor type.
Somfy's product page also suggests getting help from a Somfy professional for the install, and it ships two instruction documents: installer instructions and a consumer version. Follow the one written for your motor. Charge ports and cable routing differ between motor families, and the spec sheets and install guides for each reference sit in our Somfy spec sheet library.
The brochure lists an optional plug-in wall charger with a 6 ft cable as backup. For the 9021217 pack, Somfy's matrix names the Somfy Lithium-ion Charger V2 Head (9025166) among the chargers that fit. Keep one on hand for a run of cloudy weeks. Our guide to WireFree batteries, chargers and cables maps each charger to its motor.
AutoSun for screens and shades with no power nearby
AutoSun suits a job outside the WireFree range: an exterior solar screen on a patio wall with no outlet in reach. Somfy rates the 2009607 motor at IP 44 with Class II insulation and an operating range of -4 to 140 F. Its 6 Nm of torque and round head fit the T3.5 tube class with a 1.57 in minimum inside diameter.
| Torque and speed | 6 Nm (53.1 in-lb), 18 rpm |
| Supply | 12V DC, 9 to 15 V window |
| Current and power | 2.2 A, 26 W in operation, 0 W standby |
| Radio | Simu Hz, 433.420 MHz, 492.15 ft open field |
| Limits | Electronic, 54 turns |
| Head | Round |
| Tube | 1.57 in (40 mm) minimum inside diameter, 1.42 in motor diameter |
| Cable | RNF, 3.28 ft, Molex connector |
| Protection | IP 44, Class II, -4 to 140 F |
Somfy lists a 3.2 W AutoSun solar panel (9025235), the 2.2 Ah NiMH AutoSun battery in an aluminum case (9020635) and the Simu Battery Charger V2 (9029465) among the kit's accessories. The spare battery and charger matter on long jobs. A shaded patio in winter may need a top-up from the charger.
Control runs over Simu Hz radio. Pair the motor with a Simu Hz transmitter and follow the AutoSun programming instructions for the limits, since the steps differ from Somfy's RTS motors.
Solar, plug-in charging or a wired motor
Solar earns its place on high windows, skylight-height shades and openings where a ladder trip is the real cost of a battery motor. It adds little on a low window beside an outlet, where a charger run each season does the same work.
Wired power still wins on large or heavy shades and on jobs with daily cycling across many windows. Our comparison of Somfy WireFree vs wired motors sets out where battery power reaches its limit. Browse panels, packs and chargers in our Somfy power, battery and charger collection.
Frequently asked questions
Does the Somfy solar panel work with any WireFree motor?
It works with the Li-ion WireFree motors Somfy lists for it, such as the Sonesse 40 WireFree RTS (1240485), the Roll Up 28 WireFree RTS V2 (1241150) and external-battery motors running the 9021217 pack. Sonesse ULTRA 30 and Sonesse 28 WireFree RTS Li-ion units qualify when built after March 2020. Newer Li-ion 2 packs take a separate Li-ion 2 panel.
How many solar panels do I need for my blinds?
One per shade. Somfy's solar brochure calls for one panel per motorized window covering, mounted on the inside of that window. Each panel charges the battery of the motor it plugs into, so a room with four WireFree shades needs four panels. Windows facing east, south or west give the panels the most sun to work with.
Can a Somfy solar panel go outside the window?
The WireFree Li-ion panel cannot. Somfy specifies mounting on the inside of the window only, with direct sun passing through the glass and tint removed behind the panel. For exterior solar screens, Somfy's Simu AutoSun kit (2009607) packages a 6 Nm IP 44 motor with its own battery and solar panel, built for an opening with no power.
Do I still need a charger with a solar panel?
Keep one as backup. Somfy's solar brochure lists an optional plug-in wall charger for the WireFree system, and Somfy's matrix names the 9025166 charger for the 9021217 battery pack. Long cloudy spells, winter sun angles and heavy daily use can outpace the panel. AutoSun owners use the Simu Battery Charger V2 (9029465) for the same reason.
Sources: Somfy WireFree Li-ion Solar Panel Kit product pages (somfysystems.com and somfypro.com e-cat 9027294); Somfy WireFree Li-ion Solar Panel Brochure and Spec Sheet; Somfy WireFree Power Supply Compatibility Matrix (DOC166035); Somfy North America press release, February 28, 2023; somfypro.com e-cat 2009607, T3.5 ESP Hz 6Nm 18rpm 12V DC Kit.
Shade Motors Direct is an authorized source for genuine Somfy motorized window shade, blind, and drapery parts.
