Most modern solar systems come with a monitoring app, and it is one of the best things about owning one. It turns something silent on your roof into numbers you can check from your phone. But the app is only useful if you know what you are looking at. This guide explains what monitoring shows, what a healthy system looks like, and which warning signs are worth a phone call.
What solar monitoring actually is
Your inverter (and battery, if you have one) connects to your home wifi or a mobile data link and sends its readings to the manufacturer’s cloud. You then view them through an app or web portal. Every brand has its own app, but the core information is the same.
Some systems also fit optimisers or microinverters, which let the app show output panel by panel. That is very useful on roofs with some shading, because it shows exactly which panel is underperforming and when. We explain how that works in our guide to SolarEdge inverters and optimisers.
The numbers worth watching
- Generation: how much your panels are producing right now, and the total for the day, month and year.
- Consumption: how much your home is using, so you can see what your solar is covering.
- Import and export: what you are buying from the grid and what you are sending back.
- Battery state of charge: if you have storage, how full it is and when it charges and discharges.
- Self-consumption: the share of your solar that you used yourself rather than exported. Raising this is where most of the savings come from.
What a healthy day looks like
On a clear day, generation should rise smoothly through the morning, peak around midday and fall away through the afternoon, like a gentle hill. Cloud shows up as dips and ripples in that curve, which is perfectly normal. A south-facing roof gives a single hump. An east-west roof gives a flatter, wider curve with a morning and an afternoon shoulder.
Do not expect the same numbers in December as in June. Output in midwinter can be a small fraction of midsummer, simply because there is less daylight. The useful comparison is this month against the same month last year, or against what your installer predicted for that time of year.
Warning signs worth acting on
Most of the time, the app will just confirm everything is fine. These are the things that justify a closer look:
- Zero generation on a bright day. Check whether the inverter display shows a fault, and whether the system has simply lost its wifi connection. If the inverter shows an error and the sun is out, call your installer.
- A flat-topped or clipped curve. If output hits a ceiling and stays there, it may be an export limit or an inverter limit. That can be by design, but it is worth knowing about.
- One panel consistently lagging. With panel-level monitoring, a single panel well below its neighbours points to shading, dirt, bird nesting or a fault.
- A gradual year-on-year drop beyond normal ageing. Panels lose a little output each year. A sudden step down is not normal.
- Repeated error codes or offline alerts. One-off glitches happen. A pattern does not.
If you are unsure whether something is a fault or just weather, take a screenshot of the graph and the date and send it to your installer. That makes it far quicker to diagnose. Our guide to common problems with solar panels covers the usual causes in more detail.
Monitoring is not a substitute for a warranty
Monitoring tells you something is wrong. It does not fix it. What happens next depends on your installer and your warranties, and that is where a local team with its own employed installers makes a real difference. We explain who covers what in our guide to solar panel warranties.
Using the data to save more
Once you have a few weeks of data, the app becomes a way to save money, not just a progress report. If you can see your generation peaks at midday while your big loads run in the evening, you can shift the dishwasher, washing machine or immersion heater into the sunny hours. A home battery automates the same idea by storing the midday surplus for the evening.
It is also a good honest check on your system size. If you are exporting most of your generation, you may benefit from storage or from moving usage into daylight. If you are importing heavily even at midday, your system may be smaller than your needs.
Is monitoring included?
With almost every current inverter and battery, yes, the app is part of the package and there is no ongoing charge. It depends on a working internet connection in the property, so if your router sits far from the inverter, tell your installer at survey stage so they can plan a reliable connection, such as a wired link or a wifi extender. It is a small detail that avoids a lot of ‘why is my app offline’ calls later.
Talk to a local installer
At DES Renewable Energy, every system we fit is MCS-certified, installed by our own employed teams, and set up so you can see it working from day one. We cover Dorset, Hampshire and Wiltshire from our base in Wimborne. If you would like a system designed around your roof and your usage, request your free, no-obligation quote.