In October 2026, a fault with the SIM provider used by a large number of Sungrow EyeM4 dataloggers caused 27 sites in Diagno’s monitored fleet, totalling just over 2 MW, to lose communications over NSW’s Labour Day long weekend. Any site using the same SIM provider was likely affected, meaning the true scale of the outage was likely significant.
The communications modules on these sites do not backfill data, leaving a permanent gap in the generation record. We could not confirm whether the sites generated normally, tripped, or developed faults during the outage.
Until recently, this was the typical outcome of a communications issue. The fault creates uncertainty, but does not necessarily reduce generation. As such, communications issues typically sit at the bottom of an asset owner’s triage list.
Communications are more than monitoring
Dynamic export limits, introduced to Australian networks through the CSIP-AUS standard, rely on a continuous link between the network’s server and each site. When that connection drops, the site reverts to a fallback export limit until the connection is restored. In South Australia, the fallback is 1.5 kW after 24 hours without communications.
Increasingly, communications outages will no longer be visibility issues alone. They will become generation issues, automatically applied to every affected site for most of any extended outage.
Real system limits imposed by a SIM failure
Had these 27 sites been on dynamic export connections, every one of them would have reverted to its network’s fallback export limit for roughly four of the five days. Under South Australia’s flexible exports scheme, that fallback is 1.5 kW for a residential connection. A household system that could normally export several kilowatts at midday would instead be capped at 1.5 kW above its own consumption, automatically and with no fault showing on the inverter.
Australia has the highest rooftop solar uptake per capita in the world, and its networks increasingly depend on being able to control it. Dynamic export limits and emergency backstops are already in place or being rolled out across several states, and they rely on a robust communications link between the network and each site. This reliance will continue to grow, and communications faults will quickly become more than a monitoring inconvenience.
Communications issues must move up the priority list
Presently, communications issues are easy to overlook, on the assumption that the site keeps generating. In this outage, the affected systems did not backfill data, so almost five days of performance for these sites is permanently unknown. Diagno monitors more than 10,000 inverters and meters across Australia, and we see these outages as they happen. System owners and operators will increasingly need proactive, intelligent alerts that flag the problem before a visibility issue becomes a generation issue.
