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How Solar Works
Four steps, and only one of them involves the panels. The parts people find surprising are what happens to the electricity afterwards.
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Sunlight hits the panels and produces direct current. An inverter converts it to the alternating current your house runs on. Your home uses what it can at that moment, and anything left over charges a battery or goes to the grid. That is the whole mechanism. Almost everything that makes solar complicated is about the fourth step — what your utility pays for the surplus, and under what rules.
The four steps
01 — Sunlight reaches the panels
Photons strike the silicon cells in each module and knock electrons loose, producing direct current whenever there is usable light.
Panels respond to light, not heat. They work on cloudy days at reduced output, and they actually run slightly more efficiently in cold conditions than in extreme heat — which is why solar in cold climates performs better than most people assume.
02 — The inverter converts it
Your house runs on alternating current. An inverter makes the conversion and manages the array.
There are two broad architectures. A string inverter is one box handling the whole array, which is cheaper and means one shaded panel can drag down everything on its string. Microinverters or optimisers sit under each module, so each panel works independently and reports separately. On a shaded or multi-plane roof that difference is worth paying for. Inverter types compared goes through it properly.
03 — Your home uses it first
Production feeds whatever is running at that moment — the fridge, the air conditioning, anything plugged in. This is the electricity that is worth the most to you, because every kilowatt-hour you use on site is one you do not buy at your retail rate.
Which is why consumption timing matters. A household that is out all day exports most of its midday production; one that runs heavy loads in daylight keeps more of the value.
04 — The surplus goes somewhere
Whatever your house does not use in real time flows onward: into a battery if you have one, otherwise onto the grid.
This is the step that decides whether solar pays. Under full retail net metering an exported kilowatt-hour is worth the same as one you avoid buying. Under net billing or an avoided-cost buyback rate it is worth considerably less, which changes the right system size and makes storage more attractive. Net metering vs net billing vs buyback explains which you are on and what it is worth.
What a system is made of
Six components. Quotes list them; almost nobody explains them.
| Component | What it does |
|---|---|
| Solar panels | Silicon cells in a laminated, framed module. Rated in watts, warranted on output for roughly 25 years, and the component least likely to need attention. |
| Inverter | Converts DC to the AC your house runs on. One central unit, or small ones under each panel. Usually the first thing to be replaced — inverter warranties are commonly far shorter than module warranties. |
| Racking and flashing | Rails, mounts and the flashings that seal every roof penetration. This is where workmanship shows up years later as a leak, or does not. |
| Production meter and monitoring | Measures what the array makes and reports it. Without it, a failed string can go unnoticed for a year. |
| AC disconnect and interconnection | The switch the utility can open, and the agreement that permits your system to be connected at all. |
| Battery, if you have one | Stores production for later. Optional, and a separate decision with its own arithmetic. |
Why it shuts down in a power cut
A grid-tied system disconnects itself the moment the grid goes down, even in full sunshine. People find this genuinely surprising, and it is not a fault.
If your array kept pushing power onto the local network during an outage, it could energise lines that utility crews believe are dead. Anti-islanding protection is a code requirement for exactly that reason.
Riding through an outage requires a battery and an inverter configured for it, and even then only the circuits moved onto a critical load panel stay live. Battery storage covers what that actually gets you.
What happens over twenty-five years
Panels lose a small amount of output each year. A performance warranty states the floor — that output will still exceed some percentage of the original rating after a given period — rather than promising the panels stop at the end of it.
The inverter is the component most likely to need replacing during the system's life, because its warranty is typically much shorter than the panels'. That is a normal, budgetable event rather than a failure. Panel degradation and system upgrades cover both.
Common questions
How do solar panels actually make electricity?
Photons strike silicon cells and knock electrons loose, producing direct current whenever there is usable light. There are no moving parts and nothing is consumed — which is why panels are the most reliable component in the system and carry the longest warranties.
Do solar panels work on cloudy days?
Yes, at reduced output. Panels respond to light rather than to heat or to direct sun, so an overcast day produces a fraction of a clear one rather than nothing. Annual production estimates already account for typical cloud cover at your location.
Do solar panels work at night?
No. Production is zero after dark. At night your house draws from the grid, or from a battery if you have one. This is why a system that offsets your annual consumption still leaves you connected to the utility.
What happens to electricity I do not use?
It charges a battery if you have one, and otherwise flows to the grid, where your utility credits it under whatever export arrangement applies to you. What that credit is worth varies enormously — full retail under net metering, considerably less under net billing or a buyback rate.
Does solar work during a power outage?
A standard grid-tied system shuts down in an outage. That is a safety requirement: it stops your array energising lines that utility crews may be working on. Keeping power requires a battery and an inverter configured for it, and even then only the circuits on a backup subpanel stay live.
Do panels stop working after 25 years?
No. A performance warranty guarantees output will still be above a stated percentage of the original rating after a given period. Panels typically keep producing beyond that, at gradually declining output. The inverter is far more likely to need replacing first.
Where to go next
- What solar costs and what actually moves the price.
- Which incentives apply to you, starting with the federal position.
- How to choose an installer, which is a separate decision from choosing a system.
- What installation involves, step by step.
HyreSolar is an independent solar information platform. We do not install, finance, maintain or service solar systems.