We get called to systems that have been off for six months. Nobody knew, because solar makes no noise when it stops. The only clue is a power bill that creeps up. You can check your own system without touching anything, and it takes about five minutes on a sunny day.
Start with the lights on the inverter
The inverter is the box on the wall, usually near the switchboard or in the garage. Look at it around the middle of a clear day.
- A steady green light means it is generating. That is what you want.
- A flashing green light often means it is starting up or waiting for enough sun.
- A red or orange light, or an error code on the screen, means a fault.
- A blank screen at midday is not normal. A blank screen at night is.
If you see an error code, take a photo of the screen and the label on the side of the inverter. That photo often tells us what is wrong before we arrive.
Check the app or the screen for today's number
Most inverters show a figure for energy made today, in kWh. If yours has an app, the same number is there with a daily graph. On a clear day the graph should look like a smooth hill. A hill with a bite out of it at the same time each day is shade. A flat line is a fault.
Compare a sunny day with what to expect
As a rough guide in Melbourne, each kW of panels makes about 3.6 kWh a day averaged across the year. A clear summer day is closer to 5 or 6 kWh per kW. A clear winter day is nearer 2. So a 6.6 kW system might make 35 kWh or more on a hot January day and about 12 on a bright day in July. These are estimates. Shade, roof direction and the age of the panels all move them.
If your number is less than half of what that guide suggests on a clear day, something is worth looking at.
When to stop and call someone
Do not go on the roof, and do not open the inverter or the isolators. There is live DC voltage in a solar system whenever the sun is up, even with the mains off. If the inverter shows a fault, the app shows zero, or you can see a cracked panel or a hanging cable from the ground, ring a solar electrician.
A health check from us starts from $220 and comes with a written report and photos.