Your panels are the highest metal on the street. Ask where the lightning goes.

Quotes list panels and inverters. Protection is often one vague line.

Bengaluru's thunderstorms are most common in the pre-monsoon and post-monsoon months, and October is one of them. A rooftop solar system puts metal frames and long cable runs on top of your building, connected to your home wiring and to the BESCOM grid. Earthing and surge protection are what keep a storm, or a grid fault, from turning into damage to the inverter or your appliances. On many quotes they appear as a single line, or not at all.

Three different jobs, often confused.

Earthing gives stray current a safe path into the ground. The panel frames and mounting structure should be bonded together and connected to an earth pit, and the inverter and AC side need their own earthing. This protects people from shock if insulation fails, and it is also the base that the other protection relies on.

Lightning protection means an arrestor or air terminal that gives a direct strike a controlled route to earth instead of through your panels and wiring. Whether it is needed depends on the building and the installer's assessment, such as how tall the structure is and what already exists on the roof. Do not assume it is included.

Surge protection devices (SPDs) handle the voltage spikes that travel along cables, from a nearby strike or from the grid. Systems usually have them on the DC side before the inverter and on the AC side after it. A direct strike is rare. A surge coming in through the wiring is the more common risk.

Why this matters for the money.

The inverter is the most expensive part most likely to fail first, which is why we wrote about the inverter warranty. Warranties generally exclude damage from external causes such as lightning or surges, and the exact wording varies by manufacturer. Read your inverter's warranty terms and ask the installer to confirm in writing what is covered. A system with proper earthing and SPDs is easier to defend if you ever have to make a claim, and it is simply cheaper than replacing an inverter.

What to ask your installer.

• How many earth pits will be used, and where? Are the panel structure, inverter and AC side all connected?
• Are DC and AC surge protection devices included in the quote, and which make and rating?
• Is a lightning arrestor included? If not, why does the installer think the site does not need one?
• Will the earth resistance be tested and the reading recorded in the handover papers?
• Who is responsible if protection is found to be missing or wrongly installed?

When you compare quotes, a cheaper one may simply leave these out. Our commissioning checklist is a good time to look at the installation with this list in hand.

What you can check yourself.

You cannot test earthing without instruments, and you should never climb up or touch wiring in or before a storm. What you can do is look at the handover papers for earth pit locations and a test reading, and ask where the SPDs sit in the inverter enclosure or the distribution board. Earth pits can dry out and corrode over time, so ask for them to be inspected during routine maintenance visits, and ask whether your AMC covers it. Roof fixings also matter, as our guide on mounting structures explains.

During a storm.

Do not go to the terrace. If the inverter trips or the display is dead after a storm, do not keep resetting it. Switch the system off at the isolator only if it is safe to reach, and call your installer. Take photos and note the date, because any claim will start with a record.

The short version.

Treat earthing and surge protection as part of the system, not an extra. Get the scope in the quote, the test reading in the handover, and the warranty position in writing.