How monitoring data gets from your panels to your phone
Solar monitoring involves three distinct systems working together: the hardware that measures the electricity, the communications device that sends the data, and the cloud platform that stores and displays it. Understanding which part of this chain has failed is the key to diagnosing monitoring problems quickly.
The solar inverter is the primary measuring device on your system. It has internal energy meters that track DC power from the panels, AC power output to the home, battery charge and discharge (if you have storage), and grid import/export via the CT clamp sensor. These measurements happen continuously — typically every few seconds — and are stored in the inverter's internal memory, independent of whether the monitoring portal can receive them.
This matters: if your monitoring goes offline, the inverter continues to record locally. When connectivity is restored, most inverters sync the buffered data to the portal — though the buffer period varies by brand from 24 hours to several weeks.
The communications dongle — a small device that plugs into the inverter's RS485 or WiFi port — acts as the bridge between the inverter and the internet. It reads data from the inverter over an internal serial bus, packages it, and uploads it to the manufacturer's cloud server via your home WiFi or a wired LAN connection. Data is typically uploaded every 5 minutes, though some brands offer 1-minute resolution on premium portal tiers.
The manufacturer's cloud server receives the data, stores it in a time-series database, applies any post-processing (tariff cost calculations, CO₂ offsets, performance ratio), and makes it available through the web portal and mobile app. Each brand operates its own platform — GivEnergy Cloud, SolisCloud, FusionSolar, MySolarEdge, Enlighten, and so on. These are separate systems with different features, data retention policies, and reliability track records.
Occasional cloud outages are normal — manufacturer servers go down for maintenance or experience connectivity issues. If your dongle appears to have a working WiFi connection but the portal still shows the system as offline, check the manufacturer's status page or community forum before diagnosing the problem locally.
When you open the monitoring app on your phone, it does not connect directly to your inverter — it connects to the manufacturer's cloud server and retrieves the data that was uploaded earlier. This means you can check your system from anywhere in the world, but it also means that a problem with the cloud or with the dongle will prevent you from seeing live data even if you are standing next to the inverter. Some brands (notably GivEnergy and SolarEdge) offer a local API that allows direct connection to the inverter on your home network, bypassing the cloud — but this is an advanced feature not used by most homeowners.
What the five key monitoring figures actually mean
Most portals display the same five measurements in different layouts. Understanding what each one represents — and how it is calculated — helps you spot problems and verify the system is performing correctly.
The DC power from your panels after conversion to AC by the inverter. Measured in kW at any instant, and kWh as a daily/lifetime total. On a clear summer midday, a 4 kW system typically shows 2.5–3.8 kW depending on panel orientation and temperature.
Zero generation? Check whether it is genuinely daylight, the inverter is powered on, and the app is showing live data (not cached). If the inverter display shows output, the problem is monitoring rather than generation.
Total power demand from the home at any moment. Calculated by the inverter from the CT clamp reading plus its own output. A well-insulated UK home with moderate usage typically shows 0.3–0.8 kW base load overnight, rising to 2–6 kW when cooking or using high-draw appliances.
Zero or wrong? Almost always a CT clamp issue — check the clamp is connected, correctly oriented, and on the right cable.
The percentage of the battery's usable capacity currently stored. 100% is full, 0% is the reserve floor (typically 5–10%). The SoC should follow predictable daily cycles: charging from solar during the day, discharging in the evening, topping up from the grid during cheap-rate hours overnight.
Stuck or erratic? May indicate a BMS communication fault, a reset charge schedule, or a CT clamp direction error causing incorrect charge control.
Import shows power drawn from the national grid; export shows excess solar or battery power returned to the grid. The inverter cannot simultaneously import and export at the same instant — apparent simultaneous readings on some portals are an averaging artefact over the portal's sample window.
Unexpected export? Check your export limit setting in the inverter has not been reset — particularly after a firmware update.
Cumulative energy figures from the inverter's internal meter — separate from your smart meter. Daily generation totals are useful for day-to-day performance tracking. Lifetime generation gives a rough health check: if your 4 kW system has been installed for four years but shows fewer than 13,000 kWh lifetime (roughly 3,500 kWh per year), there may be an ongoing performance issue worth investigating.
Note: Portal totals and smart meter totals will differ slightly — they use different instruments. For SEG payments, the smart meter is the authoritative source. Use portal data for performance comparison and trend analysis, not billing disputes.
CT clamps: the hidden sensor that makes consumption monitoring possible
Your inverter can measure its own output precisely — but it cannot directly see how much power the rest of your home is using. That data comes from a CT clamp (current transformer), a clip-on sensor that wraps around your incoming supply cable and measures the AC current flowing through it.
A CT clamp works by sensing the magnetic field generated by current flow through a cable. It clips around the live conductor on your main incoming supply cable (inside your consumer unit or meter cabinet) without making electrical contact. The tiny induced current it produces is sent back to the inverter, which converts it to a power reading using the measured voltage. Because it wraps around only the incoming supply — not the solar output cable — it sees the net grid flow at any moment. From this, the inverter can deduce total household consumption by combining the grid reading with its own generation figure.
CT clamps are directional — they distinguish between current flowing into the property and current flowing out. If the clamp is installed facing the wrong direction, or if the software direction setting is reversed, the inverter reads import as export and vice versa. This causes: consumption figures that are clearly wrong (often appearing negative), battery charging at the wrong times, apparent export when the system is actually importing, and confusing portal data that shows negative consumption or negative generation.
CT clamps are calibrated sensors but not precision instruments. Small offsets (±50 W) at low consumption levels are normal and not a cause for concern. However, persistent large errors — showing 500 W consumption at 3am when you know the house is empty — may indicate the CT clamp is positioned on the wrong cable, is picking up interference from a nearby cable, has developed a fault, or has been incorrectly sized for the cable gauge. Accuracy also degrades if the cable the CT clamp wraps around is not centred in the clamp opening.
Why monitoring goes offline and how to fix it
Monitoring going offline does not mean your solar system has stopped working — in the vast majority of cases, generation and battery charging continue normally. The system just cannot send its data to the cloud. Here are the four most common causes, in order of frequency.
The most common cause. The dongle has dropped its WiFi connection — usually after a brief router restart, a broadband outage, or a signal fluctuation. The dongle should reconnect automatically, but sometimes it needs a power-cycle to prompt reconnection. Locate the dongle on the inverter (usually a small white or black device plugged into a port on the side), unplug it, wait 30 seconds, and reinsert it. Allow up to 10 minutes for it to reconnect and for the portal to update.
Check the dongle's LED: most show solid green for connected, flashing for connecting, or red/off for a fault. Consult the dongle manual for your specific indicator pattern.
If you have replaced your router, changed your WiFi password, or switched to a different network name (SSID), the dongle will still be trying to connect to the old network and will fail permanently until it is re-paired. Each brand has a different re-pairing procedure — most involve pressing a button on the dongle to put it into setup mode, then connecting to it as a temporary WiFi hotspot and entering the new network credentials. Check your inverter's dongle manual or support portal for the specific pairing steps.
Inverter or dongle firmware updates can change the communication protocol between the dongle and the cloud server, requiring the dongle to re-authenticate. If monitoring went offline shortly after you triggered a firmware update, the dongle likely needs to re-establish its server registration. A power-cycle is the first step; if that fails, check the manufacturer's update notes for any specific post-update steps required for the dongle.
See the firmware update risks guide for a full list of what to check after any firmware update.
Occasionally the manufacturer's cloud platform experiences an outage — planned maintenance, unexpected downtime, or a regional connectivity issue. If multiple users report the same platform offline at the same time, this is almost certainly a server-side problem and not your hardware. Check the manufacturer's status page or community forum. Account issues — such as a subscription lapsing, an account migration, or a portal update requiring a password reset — can also cause the portal to show no data while the dongle is actually transmitting normally.
For detailed diagnosis steps, see the full monitoring offline troubleshooting guide.
A remote diagnostic session reviews your inverter event log and portal data to pinpoint whether the fault is a dongle issue, a network problem, an account issue, or a hardware fault — without a site visit.
Monitoring portals by brand — key differences and where to find your data
Every manufacturer runs its own monitoring platform. They differ significantly in data resolution, historical data retention, API access, and reliability. Here is a quick reference for the most common UK systems.
One of the more feature-rich portals for UK homeowners. Shows generation, consumption, battery, and grid in real time with 5-minute resolution. Charge schedules, export limits, CT clamp settings, and EPS mode are all configurable from the portal. Also accessible via the GivEnergy app. Historical data retained indefinitely. API available for home automation integrations. See the GivEnergy monitoring setup guide for full portal walkthrough.
FusionSolar is Huawei's monitoring platform, available via web and mobile. 5-minute data resolution; shows PV generation, battery, grid, and self-consumption metrics. The EMMA home energy manager integrates with time-of-use tariffs directly from the app. Historical data retained for at least 10 years. Dongle (SmartLogger or SDongle) connects over WiFi or wired LAN.
SolisCloud provides live and historical monitoring with 5-minute intervals. Data logger (S3 series) connects via WiFi. Charge schedule configuration is available from the portal on newer firmware versions. App available for iOS and Android. One known limitation: historical data access beyond 12 months can require contacting Solis support.
MySolarEdge portal connects via the SolarEdge SetApp or the monitoring gateway. Provides panel-level power data (a key differentiator — Solaredge optimisers report each panel individually), system-level generation, and storage data. 15-minute resolution in the standard portal. The site image feature lets you assign panel data to a roof layout.
Enlighten provides microinverter-level monitoring — every panel reports individually. This makes it excellent for identifying single-panel failures. Web portal and app with lifetime data retention. IQ Gateway (Envoy) is the communications hub that connects microinverters to the cloud. Enlighten Manager available for installers with more detailed diagnostic data.
ShinePhone (mobile) and ShineServer (web) provide generation, consumption, and battery data. Shine WiFi-X or LAN dongle connects the inverter to the cloud. 5-minute data intervals. Historical data available for at least 2 years in the standard account tier. Charge schedules and battery settings accessible from the app on compatible models.
FoxCloud provides real-time and historical monitoring for Fox ESS hybrid inverters. The H3/H1 series uses a WiFi module for cloud connectivity. Data includes generation, battery SoC, consumption, and grid figures. Charge/discharge time periods are configurable via the FoxCloud portal or the Fox app. API available for integration with third-party platforms including Home Assistant.
SolarWeb is Fronius's monitoring platform, known for detailed energy flow diagrams and a well-designed web interface. 5-minute resolution with lifetime data retention. The Fronius Smart Meter provides consumption data; the Datamanager card handles WiFi connectivity. Fronius also supports direct MODBUS TCP/IP access for local integrations.
SunsynkConnect provides real-time monitoring and charge schedule configuration. The Sunsynk Wifi Dongle or LAN dongle connects to the cloud. A key feature is the ability to set different charge and discharge strategies for each day of the week — useful for complex tariff structures. API access available for home automation users.
The Tesla app provides monitoring for Powerwall systems, showing home consumption, solar generation (if connected), battery SoC, and grid figures. The Tesla Gateway handles monitoring and grid interaction. The app includes a Time-Based Control mode for tariff optimisation. All configuration is handled through the app — there is no separate web portal for homeowners.
AlphaCloud provides generation, battery, and consumption monitoring for AlphaESS hybrid systems. WiFi module connects to the cloud. App available for iOS and Android. Charge schedules and time-of-use settings are configurable via the app on compatible firmware. AlphaESS also provides an OpenAPI for third-party integrations.
Sigenergy's monitoring platform is built around the SigenStor system. The app and web portal provide real-time generation, battery, and grid data. As a newer system, portal features continue to develop rapidly — check the Sigenergy app for the latest configuration options and monitoring capabilities.
Moving into a house with solar — how to access the monitoring account
Monitoring accounts are registered to the email address of the original installer or homeowner. When a property changes hands, the account must be formally transferred — you cannot simply create a new account for an already-registered system.
The inverter serial number is on a sticker on the inverter body — usually on the front or side panel. For battery systems, the battery unit also has a serial number. You will need this to initiate a transfer with the manufacturer. Take a photo of it for reference.
Each manufacturer has a transfer process. GivEnergy handles transfers through givenergy.cloud — log in or create an account and use the transfer request form with the serial number and completion documents. Solis, Growatt, Fox ESS, and others require emailing their support team with the serial number, previous owner's details (if available), and evidence of property purchase. Most transfers complete within 3–10 working days.
If the original owner's account details are unknown and the installer has gone out of business, most manufacturers can still process a transfer using the physical serial number and legal proof of ownership (completion statement, Land Registry title). In some cases, the dongle must be reset and re-registered as a fresh installation — this typically causes a gap in historical data but restores full access going forward.
Once you have access to the monitoring account, verify the charge schedule is correct for your energy tariff, the export limit matches any DNO agreement, and EPS mode is configured if you want backup power capability. Previous owners' configurations are sometimes left unsuitable for new tariffs or usage patterns — it is worth a review before assuming the system is optimised for your household.
Related guides and problem pages
The hardware behind the data — what inverters do and why they're central to everything monitoring measures.
How CT clamps measure consumption, why direction matters, and what goes wrong when they're misread.
Firmware updates can disrupt monitoring communications and reset CT clamp direction — what to check after every update.
Step-by-step diagnosis for monitoring that has gone offline — covering dongle, WiFi, firmware, and cloud causes.
Specific steps for pairing or re-pairing your solar dongle to a new or changed WiFi network.
Transfer your monitoring account after buying a house with solar or after an installer has gone out of business.