A GNSS reference station consumes very little energy — often 10-40 Wh/day — but it cannot tolerate interruption without corrupting the data stream that downstream users depend on. The design problem is therefore reliability and power quality, not array size. Getting this wrong produces a station that looks fine on paper and drops out during the first thunderstorm season.
What the load looks like
- Receiver: 1-4 W continuous, sensitive to supply noise and to brownouts during firmware operations
- Radio or 4G backhaul: 2-10 W, high peak current during transmission
- Antenna and cabling: no power, but the most lightning-exposed part of the installation
- Optional met sensor or tilt sensor: negligible average, burst on measurement
With a 20 Wh/day load, a 60-100 Wp array is generous for most latitudes because the constraint is not energy but the number of consecutive no-sun days and the condition of the battery at end of life.
Design targets that actually protect uptime
| Parameter | Target | Why |
|---|---|---|
| Autonomy | 5-7 days at full load | Covers overcast periods and delayed maintenance visits |
| Voltage window | Within receiver spec at all battery states | Prevents brownout resets during transmit bursts |
| Surge protection | DC SPD on array, coax SPD on antenna | Antenna is the primary lightning entry path |
| Backup | Secondary small battery or UPS module | Rides through battery replacement without a data gap |
| Monitoring | Battery voltage and charge state logged | Early warning of degradation before dropout |
Voltage stability matters more than capacity
Receivers that reset under load create data gaps that are expensive to post-process. Two practical measures: keep the radio on its own DC branch with a local capacitor bank, and use a battery whose discharge curve stays flat across the state-of-charge range. LiFePO4 holds voltage far better than lead-acid under a pulsed load, which is why it is the default for high-uptime reference stations despite higher upfront cost.
Lightning and grounding
A GNSS antenna is a deliberate vertical element on a roof or pier, and it will attract strikes. Protect the coax with a gas discharge surge arrester at the entry point, bond the mast to the building earth, and keep the DC earth separate from the signal earth except at the single designated bonding point. Stations that skip the coax protector usually lose the receiver, not the panel.
Routine checks that prevent outages
- Log battery voltage monthly and compare to the commissioning baseline
- Clean the panel at the start and end of the dusty season
- Check torque on mast and panel fixings after storm season
- Verify the backup battery still accepts charge after two years
FAQ
How much solar power does a GNSS reference station need?
Typically 60-150 Wp of array with a 5-7 day autonomy battery, because the load is small but the uptime requirement is high.
Can I run a GNSS receiver directly from a solar panel?
No. The receiver needs a stable supply through the night and through cloud, and panel output varies constantly. A battery and controller sit between the array and the receiver.
Why does my GNSS station reboot during transmission?
Almost always voltage sag on the battery or undersized cabling between battery and radio. Check the pack’s continuous discharge rating and the cable cross-section before replacing anything.
We supply solar power for structural, dam and reference-station monitoring. Send your receiver and radio specification or see GNSS monitoring power.