A solar monitoring graph tells the story of your home's energy day. Follow the curves from pre-dawn baseload through the morning ramp, midday export and passing clouds to the evening peak, and learn what battery charge and discharge lines reveal. A solar monitoring graph is a record of your home's energy day: when the panels produced power, when the house used it, when energy flowed to or from the grid and when a battery charged or discharged. Once you know what each line means, the shape of the curves shows whether the system is working normally, how much solar the household uses directly and where changes to habits or settings could help. The walk-through below follows a typical Sydney home with solar and a battery on a mostly sunny day with some passing cloud.
What the lines on the graph mean
Monitoring apps differ in colours and layout, but most show the same set of measurements:
- Production (also called PV or solar): the power the inverter is delivering from the panels at each moment, in kW.
- Consumption (or load): the power the household is using. This needs a consumption meter or current sensors; without them, the app can only show production.
- Grid: power imported from or exported to the grid. Many apps draw import on one side of the zero line and export on the other, but conventions vary.
- Battery power: charging and discharging, again usually shown on opposite sides of zero.
- State of charge: the battery's charge level as a percentage, often on a separate axis.
The graph shows power in kW at each moment, while daily totals show energy in kWh; the area under a power curve over time is the energy. At every moment the flows balance: production plus grid import plus battery discharge equals consumption plus export plus battery charging. If one line looks odd, the others usually explain it.
A day in the life, hour by hour
| Time of day | What the graph typically shows | What is happening |
|---|---|---|
| Before dawn | Zero production, small steady consumption | Fridge, standby devices and network equipment form the baseload |
| Early morning | Production rising slowly, consumption spikes | Sun low in the sky; kettle, toaster and other appliances exceed solar |
| Mid-morning | Production overtakes consumption | Surplus begins charging the battery |
| Around midday | Production near its peak, export rising | Battery full or charging at its maximum rate; surplus flows to the grid |
| Afternoon | Production declining, occasional sharp dips | Lower sun angle and passing clouds |
| Evening peak | Production near zero, consumption high | Cooking, lighting and air conditioning; battery discharging |
| Night | Battery discharging to its reserve, then grid import | Baseload continues until morning |
Morning: the ramp and the breakfast spikes
Production begins gently after sunrise because sunlight strikes the panels at a low angle and passes through more atmosphere. East-facing panels ramp up earlier and faster than north-facing ones. Meanwhile, consumption shows narrow, tall spikes: a kettle or toaster can draw more power for a few minutes than the panels are producing. If the battery was emptied overnight, those spikes appear as brief grid imports even on a sunny morning.
Midday: peak production and export
On a clear day the production curve forms a rounded hill peaking around solar noon, which in Sydney falls close to 1 pm during daylight saving time. As a rule of thumb, a 6.6 kW system in Sydney produces roughly 24-27 kWh a day averaged across the year, more in summer and less in winter. The peak on the graph usually sits below the array's rated size, because panels lose output when hot, sunlight is rarely at the ideal angle and the inverter may be rated below the panel capacity.
A curve with a perfectly flat top at the same value on every sunny day usually indicates inverter clipping or an export limit rather than a fault. Because exports now earn far less than the retail price of imported electricity, as explained in understanding feed-in tariffs, a large midday export area suggests that moving some household loads into these hours could add value.
Clouds: dips, spikes and smoothing
Passing clouds produce sudden, deep dips in production lasting seconds or minutes. Just before or after a cloud, production sometimes rises briefly above the clear-sky level, because sunlight scattered from bright cloud edges adds to direct sun. On a graph with five-minute or longer intervals these effects are averaged, so the curve looks smoother than the real moment-to-moment output.
A battery absorbs much of this variability. When production dips below consumption, the battery discharges to cover the gap, so the grid line may stay close to zero while production jumps around. Fully overcast days look different again: a low, flattened hill without sharp edges.
Evening and night: the battery's shift
As production fades in the late afternoon, household demand usually rises. The battery discharge line mirrors the consumption line, supplying the home until the state of charge reaches its reserve setting or the load exceeds the battery's maximum output, at which point grid import fills the difference. On a time-of-use tariff this part of the graph matters most, since evening imports are typically the most expensive, as outlined in understanding time-of-use tariffs.
The overnight baseload is worth noticing too. A consumption line that never drops below a relatively high level through the night can point to an old second fridge, pool equipment running after dark or devices that never switch off.
Patterns worth investigating
Graphs vary from day to day for ordinary reasons such as weather. Some patterns, though, deserve a closer look by a professional:
- zero production on a sunny day, which may indicate a tripped isolator, an inverter fault or a lost data connection
- production that cuts off sharply and repeatedly on sunny days, which may mean the inverter is disconnecting because of high grid voltage
- peak production clearly lower than in the same month of previous years, beyond normal ageing
- a lopsided curve on clear days that suggests new shading from trees or buildings
- a battery that stops charging or discharging when conditions suggest it should
Never open the inverter or go onto the roof to investigate; faults should be diagnosed by a licensed electrician or accredited installer.
Next steps
If your app shows only production, adding consumption monitoring reveals the rest of the story. The energy market lists an Energy Monitoring Dashboard from $590 and a System Performance Audit from $390, which compares 12 months of generation with modelled output; prices are indicative and confirmed after a site assessment. If your graph suggests a battery or a larger system could put more of your solar to use, request a free assessment from Blue Energy Solar.
Frequently asked questions
Why do my app's totals differ from my electricity bill?
The app and the bill measure at different points. The inverter or monitoring sensors record production and household use, while the utility meter records only what crosses the property boundary as import and export. Sensor accuracy, data gaps when the internet connection drops out and billing periods that do not align with calendar months all add small differences. Over a full quarter the figures should broadly agree.
Why does my graph look so different in winter?
In winter the sun rises later, sets earlier and stays lower in the northern sky, so the production hill is narrower and shorter. Low sun also lengthens shadows from trees, chimneys and neighbouring buildings, which may shade panels that are clear in summer. Cooler panel temperatures help efficiency slightly, but not enough to offset the shorter days and weaker sunlight.
How often should I check the monitoring app?
A quick look every week or two is usually enough to catch a problem before it costs much production. Many apps can send notifications for faults or loss of communication, and those are worth enabling. Keeping the app's tariff rates and system details up to date also makes any savings estimates it displays more meaningful.
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