How solar actually works
Four explanations, written for someone who has not decided anything yet: what is inside a panel, what each box on the wall does, what changes on your bill, and what keeping it all running actually involves.
Start anywhere
These four pages are independent. Read them in any order. If you are not sure where to begin, start with the bill, because it is the part that decides whether any of the rest is worth your money.
Anatomy
Inside a solar panel
Components
How a solar system works
Billing
Import and export units
Upkeep
Solar maintenance
The whole thing in five sentences
01
Panels make DC
Sunlight frees electrons in silicon cells and the cell structure pushes them one way. That is direct current, and it is what leaves the roof.02
The inverter makes AC
Your appliances and the grid both run on alternating current. The inverter converts, and while doing so it also decides how hard to push the panels for maximum output.03
Your building uses it first
Generation goes to whatever is switched on at that moment. Only the surplus goes anywhere else, which is why what you run during daylight matters.04
The surplus goes to the grid
A bidirectional net meter records what you export as well as what you import, keeping the two as separate running totals.05
The bill nets them off
Your DISCOM offsets exported units against imported ones according to net-metering rules set by the state regulator — TGERC in Telangana, APERC in Andhra Pradesh. That netting is the whole financial mechanism.06
And then it just runs
There are no moving parts in a rooftop PV array. Maintenance is cleaning, inspection and eventually one inverter replacement, not an engine to service.
Common questions
How does a solar panel actually generate electricity?
Sunlight arrives as photons. When a photon strikes the silicon in a solar cell it can knock an electron loose, and a junction built into the wafer pushes those freed electrons in one consistent direction rather than letting them wander. A directed flow of electrons is a current: direct current, in this case. Everything else in a solar system exists to protect that process, convert its output, or measure it.
Do solar panels work in cloudy weather?
Yes, at reduced output. Panels respond to light, not to heat, so an overcast day still produces, considerably less than full sun, but not nothing. Heat is in fact the opposite of helpful: cell efficiency falls as temperature rises, which is why a cool bright day can out-produce a hot one.
What happens to my solar system during a power cut?
A standard on-grid system shuts down. This is anti-islanding: a legal safety requirement that stops a grid-tied inverter from feeding power into lines a lineworker may believe are dead during a grid failure. It is not a fault — it is the inverter doing exactly what it is designed to do.
How long does a solar installation last?
Panels are typically warranted for performance over about 25 years and degrade slowly rather than failing outright. The inverter is the shorter-lived component and should be expected to need replacement once in that period. Cables, connectors and the mounting structure last well if they were specified correctly at the start and are inspected periodically.
Where should someone new to solar start?
With the bill. Understanding what import and export units are, and how net metering nets them off, tells you what solar can and cannot change about what you pay. Once that is clear, the components and the panel construction make far more sense, because you can see what each part is contributing.
Once the theory makes sense, the roof decides the rest
Orientation, shading and your actual consumption pattern are things nobody can assess from a webpage. A free site survey gives you numbers for your property rather than a national average.