A 15 W PoE access point looks tiny, but it draws 360 Wh a day, every single day, with no sleep cycle. That's more than many solar security cameras use in a week: cameras nap between motion triggers, WiFi gear can't. Solar can power WiFi access points, routers, and hotspots off-grid, but only if the panel and battery are sized for a constant load, not a daytime-only load.
- WiFi gear is a constant 24/7 load (typically 5-25 W depending on the device), so both the solar panel and the battery bank need sizing against your worst production month, not an average one; undersizing for winter is the most common field failure.
- A 12V battery-direct DC architecture with a PoE injector avoids the conversion losses of running an inverter just to feed a standard AC adapter, and it simplifies the wiring for remote or unattended sites.
- Custom panel sizes and 7-14 day samples are available for fleet and OEM deployments that need a specific form factor, voltage, or mounting footprint before committing to a full order.
This guide walks through the power budget math for 24/7 WiFi loads, the sizing formula for panel and battery capacity, the 12V/PoE architecture that outperforms an inverter setup, real deployment scenarios from remote gates to construction trailers and campgrounds, and the sourcing path for custom panels. Production runs 3-4 weeks, with shipping to 20+ countries.
Can WiFi Run on Solar? The 24/7 Power Problem
Yes — WiFi routers, access points, and hotspots run reliably on solar power, but only when you size the system for a constant 24/7 load. The design failure mode isn't the panel or the battery chemistry; it's treating a WiFi radio like a duty-cycled device when it isn't one.
Most solar-powered field electronics get their power budget from intermittent use. A security camera or a soil sensor wakes up, captures data, transmits, and sleeps, so its average draw over 24 hours is a fraction of its peak draw. That low duty cycle is why a small panel and a modest battery can carry a camera through the night.
A WiFi radio doesn't work that way. Routers and access points beacon continuously to keep the network discoverable, whether or not a client is connected. Draw stays near-constant hour to hour, which multiplies the watt-hours consumed per day compared to a duty-cycled sensor pulling the same peak wattage. Undersizing here isn't a rounding error. It's the single most common reason a "solar WiFi kit" runs the battery flat by week two.
The panel and battery have to be sized against that continuous draw, not the device's peak spec sheet number. This is the same contrast we cover in solar WiFi camera systems across farm buildings, where cameras' low duty cycle lets a smaller array carry more devices than a WiFi node ever could on the same footprint.
There's a second trap layered on top: backhaul. A solar WiFi node still needs an internet source somewhere upstream (a cellular modem, a point-to-point wireless bridge, or a satellite terminal), and that backhaul radio adds its own constant draw to the same power budget. Typical off-grid WiFi deployments underestimate total watt-hours by ignoring this second radio entirely, then wonder why the math from the router's datasheet alone doesn't hold up in the field.
Power Budgets: Routers, Access Points, and PoE Classes
One number decides the whole solar system design: the device's real continuous draw in watts. The PoE class printed on the spec sheet is a ceiling, not the actual draw: a router rated for 802.3at (PoE+) at 30W might only pull 8W in normal operation. Size the battery and panel around the measured or vendor-typical wattage, not the port class.
| Device type | Typical continuous draw | Typical daily energy |
|---|---|---|
| Home/SOHO router | 5-10 W | 120-240 Wh/day |
| Outdoor access point (802.3af PoE) | 8-13 W | ~190-310 Wh/day |
| High-power AP (802.3at PoE+) | 15-25 W | 360-600 Wh/day |
| Point-to-point wireless bridge radio | 4-8 W | ~100-190 Wh/day |
| Cellular router/gateway | 5-10 W | 120-240 Wh/day |
PoE standards set the port ceiling, not the device draw. IEEE 802.3af delivers up to 15.4W at the port, 802.3at (PoE+) up to 30W, and IEEE 802.3bt up to 90W using all four pairs. Actual device consumption usually sits well below the class ceiling. Pull the vendor's typical-draw figure from the datasheet, then add the injector's own conversion overhead on top.
Before finalizing panel and battery sizing, run the device on an inline power meter for a full day and log the actual watt-hours consumed; vendor numbers are a starting point, not a substitute for measured load.
Sizing Panel and Battery for Always-On WiFi
For a 24/7 load, daily watt-hours equal continuous draw in watts times 24 hours. Divide that figure by your worst-month peak sun hours, then multiply by a loss factor of roughly 1.4 to size the panel. Battery capacity is daily watt-hours multiplied by autonomy days, typically 3-5 for connectivity gear people depend on.
Size for the worst month, not the annual average: a system that balances on May sun hours will brownout the access point in December. Peak sun hours are the hours of sun-equivalent-to-1000W/m² a location gets in a day, and that number swings 2-3x between summer and winter at most latitudes.
Example: a 12 W access point plus PoE injector draws 288 Wh/day (12 W × 24h). At 2 peak sun hours in the worst month, 288 Wh ÷ 2 gives a 144 W base, and with a 1.4 loss factor for wiring, MPPT conversion, and angle mismatch, you land on roughly a 200 W panel. Battery sized for 4 days of autonomy needs about 1,150 Wh, roughly 90-100 Ah of usable capacity at 12 V. Treat it as a sizing method, not a guarantee.
LiFePO4 and sealed lead-acid both hold up outdoors, but the trade-off shifts once the load cycles daily instead of a few times a year. LiFePO4 rates for 2,000-4,000+ cycles at 80% depth of discharge versus 300-500 for sealed lead-acid, which matters directly for a router that discharges and recharges every single day. LiFePO4 packs also need a cold-charge cutoff below 0°C to avoid damaging the cells, so check the built-in BMS spec if the install sees freezing nights.
See our battery chemistry guide for remote monitoring for the full comparison. Sealed lead-acid costs less upfront but weighs roughly 3x more per usable Wh, which matters when the mount is on a pole with ladder-access only. Batteries aren't part of the panel kit — customers source them locally to match voltage and mounting constraints.
System Architecture: 12V DC, MPPT, and PoE Injection
The reliable architecture for a solar-powered WiFi node is battery-direct DC, with no AC inverter anywhere in the chain: panel → charge controller → 12V battery → DC-DC converter or passive PoE injector → device. Every conversion stage costs efficiency, and an inverter is the stage worth cutting first.
An inverter idles at several watts even with nothing plugged into it, often more than the WiFi radio and PoE camera combined draw at idle. On a system sized for winter sun hours, that parasitic draw is the difference between a battery bank that survives a three-day cloud front and one that doesn't. It's also one more component that can fail in the field, on a mast, in the rain.
MPPT versus PWM comes down to load profile. A WiFi node runs 24/7/365, including short winter days when every extra watt harvested matters, and that favors MPPT's 10-30% harvest advantage over PWM. PWM is acceptable only on small systems where panel voltage is closely matched to battery voltage and budget is the binding constraint.
Powering PoE devices from a 12V bank means either a passive PoE injector or a 12V-to-48V PoE step-up converter, depending on what the device expects. The catch: 802.3af/at devices expect negotiated power delivery, while passive injectors skip negotiation entirely and just push voltage down the line. Match injector output voltage to the device's PoE spec exactly, or you risk underpowering the radio or camera at the far end.
Enclosure and wiring details decide whether this survives a season outdoors. Junction points need an IP67 rating minimum. Fuse the battery output before it reaches anything else. On cable runs over 15-20 meters, check voltage drop against the device's minimum input spec: a PoE camera that browns out on a long run looks like a bad unit when it's really a wiring problem.
- Mount the panel and run its output to the charge controller input.
- Connect the charge controller's battery terminals to the 12V battery bank.
- Fuse the battery's positive lead before any downstream wiring.
- Run fused 12V output to the DC-DC converter or passive PoE injector, matched to the device's voltage spec.
- Connect the injector's data+power output to the WiFi device via IP67-rated connectors.
For wire gauge tables and a full parts-level wiring diagram, see LinkSolar's 12V solar wiring architecture guide.
Deployment Scenarios: Farms, Bridges, Construction, Substations
The same battery-direct architecture (panel, charge controller, battery, load) covers four recurring deployments: farm WiFi coverage, bridge and structural monitoring gateways, temporary construction site connectivity, and utility substation telemetry. What changes across them isn't the wiring; it's the load size and the autonomy target the battery has to hold, since a farm access point idles most of the day while a substation gateway runs continuous duty regardless of season.
The most common ask is extending WiFi from a farmhouse router to barns, equipment sheds, and outbuildings that sit past normal range. A point-to-point wireless bridge between two buildings, each end running off its own solar-battery pack, avoids trenching a cable run across a field or paddock. Typical loads are modest, like a WiFi access point powering a barn camera or an automated gate controller, but the building is often the last one on the property line, where mains power isn't worth trenching for a single load.
A structural-monitoring integrator we work with specced solar power for a bridge-deck vibrometer feeding a LoRaWAN gateway that logs vibration data for long-term structural monitoring. The vibrometer itself draws very little current. The gateway, running its radio and cellular or Ethernet backhaul continuously, is what actually sizes the panel and battery.
Job trailers and site offices need connectivity that moves when the site does. A panel-and-battery skid that relocates with the crew beats running temporary grid power or trenching for a project that lasts months, not years.
A transmission-utility contractor in Peru is deploying hybrid systems, current-transformer (CT) harvesting paired with solar, to power transmission line and substation monitoring points, where the communications gateway has to stay online around the clock regardless of line load. That always-on gateway duty cycle is close to what a LoRaWAN gateway pulls (see our guide to solar panel sizing for LoRa gateways); where the backhaul is cellular instead of WiFi or LoRa, the sizing math shifts closer to what we cover in solar power for 4G LTE gateways.
Sourcing Panels for WiFi and Gateway Fleets
Fleet deployments live or die on repeatability — the same panel spec, bracket, and connector across 20 nodes or 200, and that's a sourcing problem before it's an engineering one. Buy retail one-offs and every node ships with a slightly different voltage output, a different connector, a different mounting hole pattern. Standardize on one panel SKU per node class instead, and field installs get faster because the crew isn't matching parts on-site, and a single spare pool covers the whole fleet.
Certification paperwork only needs collecting once per SKU, not once per shipment. Ask your supplier for the IEC 61215 test report, CE and RoHS documentation if any nodes land in the EU, and ISO 9001 QC traceability so you can trace a bad batch back to a production run. As a sourcing partner, LinkSolar pulls these documents from our manufacturing partners and runs factory-side QA per batch, so the file lands with the first order, not after a customs hold.
Hardware details are worth speccing before quoting, not after the first field failure. IP68 connectors matter on exposed pole mounts where the panel sees rain and dust year-round; junction box position and cable length need to match your enclosure layout so installers aren't splicing extensions in the field. Mounting hardware should be locked too: pole and wall brackets rated for your install environment, and if any nodes go up in North America, installers will ask about UL 2703 compliance on the mounting system specifically.
Work the sample-first way: order samples before committing to a production run. Verified turnaround is 7-14 days for samples and 3-4 weeks for production, with shipping to 20+ countries so multi-region fleets can source from one supplier instead of juggling three. Reference points from the current catalog: mini panels start at 0.11W for $9.90, scaling to 25W with MPPT at $85.60; larger and custom sizes are quoted against your fleet's actual power budget.
For fleet-specific sizing math and enclosure integration notes, see the integrator guide to remote solar power; for the full remote solar power systems range this sourcing approach draws from, browse current stock and quote paths.
Frequently Asked Questions
Can Wi-Fi be solar powered?
Solar power can run Wi-Fi hardware around the clock when the panel, battery, and charge controller are sized for the device's continuous draw. A typical outdoor access point pulling 5-10 W needs a 100-200 W panel paired with several days of battery autonomy to survive mid-latitude winters, though exact sizing depends on your site's worst-month sun hours.
How can I get Wi-Fi off-grid without an internet provider nearby?
The Wi-Fi radio only distributes a connection locally; it can't manufacture internet access on its own. The backhaul has to come from somewhere else: a cellular modem, a point-to-point wireless bridge from a connected building, or a satellite terminal. Each of those adds its own continuous power draw, so size the solar budget around the backhaul device, not just the access point.
Do solar-powered Wi-Fi extenders work?
Consumer all-in-one solar extenders exist and can work for casual, fair-weather use. Their built-in panels are small, though, and struggle to keep up with continuous draw once winter sun hours drop, which is why anything mission-critical needs a separately sized panel and battery rather than the integrated unit.
How big a solar panel do I need for a Wi-Fi router?
Multiply the router's continuous power draw in watts by 24 to get daily watt-hours, divide by your site's worst-month sun hours, then multiply by roughly 1.4 to cover charge controller and battery losses. A typical 8 W router lands in the 100-150 W panel range for northern winter sites, though your own draw and location will shift that number.
Designing WiFi Power That Survives Winter
The sizing logic in this guide comes down to four steps: measure the device's real draw instead of trusting the datasheet, size the panel and battery for December's sun hours rather than the annual average, run the load DC-to-DC off the battery instead of through an inverter, and lock the winning combination down as a standard SKU once you're deploying more than a handful of units. Skip the first step and every number after it is wrong; skip the standardization step and every fleet install becomes its own one-off engineering exercise.
Next step: meter your device's actual draw for 24 hours, look up your site's worst-month sun hours, and run the two formulas above. That gets you a panel and battery range you can start pricing instead of guessing at.
Ready to spec it? Request a quote with the device model (or its measured draw), the site location, and the mounting situation, and our engineering team will confirm panel wattage, controller type, and bracket fit before you order anything. Samples ship in 7-14 days once specs are confirmed.
