The architecture
A 100W panel and small LFP battery power a PoE injector/DC converter and outdoor bridge radio. If the far end needs local Wi‑Fi, a second AP hangs off the bridge. The system stays DC; PoE voltage comes from a DC boost converter or native passive-PoE adapter.
Load and sizing math
Outdoor radios are steady loads. Ten watts that never turns off is 240Wh/day, so networking consumes more energy than many people expect.
| Load | Watts | Hours/day | Daily Wh | Notes |
|---|---|---|---|---|
| Bridge radio | 7 | 24 | 168 | Always on |
| Remote AP | 5 | 24 | 120 | Optional |
| PoE conversion loss | 2 | 24 | 48 | Allowance |
| Illustrative total | 336 Wh/day | Before system margin | ||
A bridge + AP can approach 336Wh/day. In that case a 30Ah battery is marginal; 50Ah is more comfortable. If only one bridge radio runs, the project can be smaller.
Full parts list
This is a shopping architecture, not a demand that you buy one exact brand. Match voltage, current and connectors before ordering. Budget ranges reflect the class of hardware rather than a live quote.
100W–200W solar panel
Target spec: Size to 1 or 2 radios and winter sun
Networking is a 24-hour load.
Budget: $55–$240 each
30–50Ah LiFePO4 battery
Target spec: 12.8V
Provides overnight/cloud reserve.
Budget: $65–$180 each
10A–20A controller
Target spec: Low-voltage load output
Automatically protects battery.
Budget: $25–$100 each
Outdoor point-to-point bridge pair
Target spec: 5GHz directional radios
Creates the long-distance backhaul.
Budget: $80–$250 each
DC PoE converter
Target spec: 12V to 24/48V PoE as radio requires
Avoids an always-on AC inverter.
Budget: $20–$70 each
Weatherproof mast enclosure
Target spec: Pole-mounted with glands
Protects controller, battery and network hardware.
Budget: $35–$120 each
Wiring map
Power the radio from DC PoE rather than AC. Keep Ethernet drip loops and surge protection in mind on exposed masts.
[PV]-->[CTRL]-->[LFP]-->[DC PoE]-->[Bridge Radio] )))))) [House Bridge]
|
optional AP
at far site
Step-by-step build
Prove line of sight
Use binoculars, mapping and temporary tripods. Trees in the Fresnel zone can kill a link that 'looks clear.'
Bench-configure both radios
Set SSIDs, IPs, encryption and management access before climbing a ladder.
Mount the solar/network mast
Separate panel and radio enough that the panel does not block the antenna beam.
Install DC PoE conversion
Verify exact output voltage and polarity before connecting the radio.
Aim the bridge
Use signal-level tools in the radio UI and lock mounts after alignment.
Add the local AP if needed
At the far end, bridge Ethernet into a weather-rated AP or switch.
Run overnight on battery only
Disconnect PV after sunset and confirm SOC remains healthy through the next morning.
Test recovery
Force low-voltage shutdown or power cycle and make sure the network rejoins automatically.
Commission it before you trust it
The project is not finished when the LED comes on. Run it through a controlled test so the first real failure is not in the field.
- Line of sight confirmed
- PoE voltage verified
- Radio management password changed
- Surge/drip loops installed
- Battery autonomy tested
- Low-voltage recovery tested
- Mounts torqued
- Remote reboot method documented
- Speed test saved as baseline
Mistakes to avoid
Undersizing the battery because the panel is large
Panels make energy only when conditions cooperate. The battery has to carry the load through night, cloud and short high-demand events. Size energy storage from watt-hours, not panel watts.
Ignoring standby loads
Controllers, routers, cameras, inverters and cellular hardware can consume power 24/7. On small projects, a 5W always-on device is 120Wh per day—sometimes more than the 'main' load.
Using one fuse for the entire project
Fuse each branch according to its conductor and load. The fuse protects wire, not the gadget. A downstream short should not require an oversized main fuse to clear.
Mounting the panel where the project is instead of where the sun is
The load can sit in shade. The panel cannot. Use a cable run, pole or remote mount to put the collector in the best solar window.
Skipping a low-voltage disconnect
Deep-discharge protection is cheap insurance. Many charge controllers or smart battery systems can disconnect noncritical loads before the battery is abused.
Upgrade path
Add a second network branch
Power a camera cluster or weather station from the same remote node.
Add LTE failover
A small cellular router can back up the bridge at mission-critical sites.
Add larger battery for snow season
Always-on radios make winter autonomy the key design constraint.
Frequently asked questions
How far can a point-to-point bridge go?
With clear line of sight, outdoor directional systems can cover far more than ordinary Wi‑Fi; exact range depends on hardware, interference and regulations.
Why not use an inverter?
DC PoE avoids continuous inverter idle loss.
Can the radio run directly from the panel?
Not reliably; a battery buffers clouds and provides 24-hour operation.
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