A solar farm monitoring station sits far from the nearest substation, and when the local feeder drops, the SCADA host, meteorological sensors and communications radios that the operator depends on go dark with it. A properly sized UPS keeps that telemetry online through any grid event, and at a typical edge site the protected load is small enough that a 10 to 60 kVA unit delivers 99.9 percent availability for the control layer at a modest cost. The whole point is continuity of data, not backup of the array itself.
These sites are not server rooms. They are usually an unstaffed cabinet beside the collector roads, fed by a long, exposed overhead line that sees more voltage sag and outage minutes than a town supply. Inside the cabinet the load is a controller, a small switch, a cellular or microwave radio, a weather station and perhaps a security camera. Total draw is often one to three kilowatts, with short peaks when radios transmit. That is a perfect UPS load: low power, high consequence if it disappears.
The consequence is not lost production. A few minutes of missing SCADA data can mask an inverter fault, a combiner trip or a vegetation fire on the right-of-way, and the operator only finds out when the next scheduled poll arrives hours later. Keeping the monitoring layer alive is what lets a fault be caught and dispatched the same day rather than the next week.
The protected set is the telemetry and control chain, not the power conversion equipment. Inverters ride through short interruptions on their own, and they do not need the UPS. What needs the battery is everything that tells the operator what the plant is doing:
None of that is large, which is why a compact double-conversion unit in the same cabinet is the standard answer rather than a separate battery room. Our solar and storage backup options are described at https://www.upsboss.com/solar-storage/.
Measure the cabinet load at the breaker, not the nameplate. A typical monitoring cabinet runs 800 W to 2 kW continuous, with radio transmit peaks adding a few hundred watts for milliseconds. A 3 kVA UPS at 0.9 output power factor delivers about 2.7 kW, which covers the cabinet with headroom and absorbs the transmit surge. Larger sites with multiple cabinets or a local edge server might use 10 kVA, and a site that also protects a small control building can reach 60 kVA.
Size at 70 to 80 percent of rating so the unit is never near its ceiling, and confirm the power factor of the load. A router or radio with a poor power factor draws more volt-amperes than watts, and the UPS is rated in both. The full range of cabinets and units is listed at https://www.upsboss.com/products/.
The supply at a remote site is dirty. Long feeders sag, transformers switch, and nearby lightning injects transients that a radio front end hates. A line-interactive unit corrects voltage in steps but still passes the input frequency and most transients. An online double-conversion unit regenerates clean output continuously, so the SCADA host and radios see a steady waveform whatever the line is doing. For a cabinet whose only job is reliable data, that isolation is worth the small extra loss.
Efficiency is not the priority here. A 2 kW load at 96 percent double conversion wastes about 80 W, a rounding error next to the value of uninterrupted telemetry. Where the cabinet is solar-fed and off-grid part of the year, that loss is still trivial against the data it protects.
Most monitoring cabinets have no generator. Runtime is therefore a business decision: how long must the site keep reporting after the grid fails? Ten to thirty minutes is the common target, long enough for a grid event to clear or for an alarm to reach the operator and trigger a site visit. Lithium iron phosphate is the better chemistry for these cabinets because it tolerates the wide temperature swing of an outdoor enclosure and lasts eight to ten years against three to five for sealed lead-acid.
If the plant already has a standby generator for the collection system, the UPS only has to bridge the start and stabilisation gap, usually under ten minutes, and the battery can shrink accordingly. Either way, size the battery for the worst summer temperature, because heat is what quietly shortens battery life.
A UPS in a cabinet nobody visits must report its own state. Networked units push battery state of health, last transfer event and remaining runtime to the same SCADA that the rest of the plant uses, so a failing battery raises an alarm before it strands the site. Pair that with a managed power outlet that can cycle a locked-up router, and most faults become a remote reboot instead of a drive to the far corner of the array.
This is where the investment pays back. The cost of a 10 kVA UPS and a lithium battery is small next to a single wasted site visit, and the value of catching an inverter trip the same hour it happens is hard to put a number on until the first one is missed.
Send us the cabinet load and the local supply history and our engineers will return a sized UPS and battery configuration for the site. Start with the options at https://www.upsboss.com/solar-storage/ and the full unit range at https://www.upsboss.com/products/.
Key takeaway: a solar farm monitoring station needs a UPS for its telemetry and control layer, not its array. A small double-conversion unit with lithium batteries and remote monitoring keeps the data flowing through grid events that would otherwise blind the operator for hours.
Does the UPS need to back up the solar inverters?
No. Inverters ride through short interruptions themselves. The UPS protects the SCADA, communications and sensors that report what the plant is doing, which is what an operator actually loses during an outage.
How long should the battery last?
Ten to thirty minutes covers most grid events and alarms; if the site has a generator, under ten minutes bridges the start gap. Lithium chemistry is preferred for outdoor cabinets because it survives the temperature swing.
Can the UPS be serviced remotely?
Largely yes. Networked monitoring reports battery health and transfer events, and a managed outlet can reset a stuck radio. Physical battery replacement still needs a visit, but that becomes planned rather than emergency.
Contact: Frank Zhang
Phone: +86-135 5688 8641
Email: frank@upsboss.com
Add: Jufeng Road, Guangming Street, Guangming District, Shenzhen City, Guangdong Province, China
