Establishing high-speed internet links across miles of rugged terrain often requires installing solar-powered relay towers on mountain ridges, grain silos, or remote hilltops. These solar repeater nodes host point-to-point (PtP) wireless bridges, LTE/5G cellular modems, meteorological telemetry sensors, and automated irrigation controllers.
Because site access may require snowmobiles or four-wheel drive vehicles, maintenance visits must be kept to zero. The power system must be engineered for continuous year-round autonomy, transient lightning suppression, and ultra-low quiescent power draw.
1. Why 24V DC is the Telemetry & Wireless Standard
In the wireless internet service provider (WISP) and telemetry industry, the overwhelming majority of outdoor radios—including Ubiquiti Networks (airMAX, airFiber, UISP) and MikroTik RouterBOARDs—operate natively on 24-Volt Passive PoE (positive voltage on pins 4 & 5, negative ground on pins 7 & 8).
[2x 200W Solar Panels] ──► [24V MPPT Controller] ──► [24V 100Ah LiFePO4 Battery]
│
▼
[24V Passive PoE Injector / Switch]
│
┌───────────────────────┴───────────────────────┐
▼ ▼
[PtP 5GHz Wireless Bridge] [Industrial LTE/5G Modem]
(e.g., Ubiquiti NanoBeam: ~6W) (e.g., Teltonika RUTX50: ~7W)By standardizing on a 24V battery architecture, incoming battery voltage connects directly into passive PoE midspans and radios with zero DC-DC conversion steps. This eliminates conversion inefficiencies, reduces circuit component counts, and maximizes mean time between failures (MTBF).
2. Telemetry Node Power Budget Analysis
| Hardware Component | Nominal Operating Draw | 24-Hour Duty Cycle | Daily Energy Overhead |
|---|---|---|---|
| 5 GHz High-Throughput PtP Wireless Dish | 6.5 Watts | 100% Continuous | 156 Wh |
| Industrial Cat 4 / 5G Cellular Gateway | 7.0 Watts | 100% Continuous | 168 Wh |
| Ultrasonic Weather Station / LoRaWAN Hub | 1.5 Watts | Polling 1x per min | 36 Wh |
| MPPT Charge Controller Quiescent Draw | 0.8 Watts | 24 Hours | 19 Wh |
| Total Continuous Station Power | ~15.8 Watts | — | ~379 Wh per day |
A continuous load of 15.8 Watts translates to ~0.66 Amperes at 24V. Over a 24-hour day, the node consumes roughly 380 Watt-hours.
3. Battery Bank & Winter Solar Dimensioning
Because remote telemetry stations are frequently situated on windy, cloud-prone peaks, a 5-day autonomy reserve is mandatory to survive extended winter storm fronts:
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Usable Battery Capacity: 379 Wh/day × 5 = 1,895 Usable Watt-hours.
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Nominal Bank (at 80% DoD): 1,895 ÷ 0.80 = 2,369 Nominal Wh (~100Ah at 24V LiFePO4).
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Array Sizing (at 2.5 Winter Peak Sun Hours):
Required Array = 379 Wh/day ÷ (2.5 PSH × 0.64) = 237 WattsSpecifying two 200W or two 250W panels (400W–500W total) provides double the baseline winter generation, ensuring the battery bank fully recovers within a single sunny afternoon after a multi-day storm.
4. Lightning & Static Dissipation (Motorola R56 Standard)
Mounted at high elevations on metal towers or masts, telemetry nodes are prime targets for atmospheric electrostatic accumulation and nearby lightning strikes:
- Gas-Discharge Tube (GDT) Ethernet Surge Protectors: Install an outdoor-rated RJ45 lightning arrestor (such as a Ubiquiti ETH-SP-G2) at the base of the mast before cables enter the equipment box, clamping transients to ground in nanoseconds.
- Dedicated Tower Ground Rod: Bond the mast to an 8-foot copper ground rod using heavy 2 AWG bare copper wire, keeping bend radii smooth and wide (minimum 8-inch radius) to provide a low-impedance path to earth.
Calculate your remote node’s exact battery runtime using our Battery Runtime Calculator.