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How a rooftop solar system actually works
Panels turn light into DC electricity. The inverter converts that to AC and pushes it into your distribution board, where the house consumes it before drawing anything from the grid. Surplus flows back through a bidirectional meter as credit. Nothing is stored unless a battery is fitted.
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The house consumes first, always
This is the part people misunderstand. Solar does not fill a tank you draw from later — generated power goes into your board and is consumed by whatever is switched on at that instant. Only what is left over leaves the property. A fridge running at noon is being powered by the roof directly, with no meter involved at all.
What the inverter is really doing
Beyond converting DC to AC, it constantly hunts for the voltage at which the array produces most power — the maximum power point — which shifts with light and panel temperature. It also synchronises precisely with the grid's waveform, and disconnects the instant the grid drops so it cannot backfeed a line someone may be working on.
Where the meter comes in
A standard meter only counts forward. A bidirectional meter counts import and export separately, which is what net metering requires. Without one, exported units are simply given away — the meter has no way to record them, and on some older meters exporting can even read as additional consumption.
What changes when a battery is added
A battery inserts storage between generation and consumption, so surplus charges the bank instead of leaving the property, and the bank runs a backed-up circuit when the grid fails. It does not make the system generate more; it changes when you can use what was generated, which is a different benefit and priced separately.
How does solar power work on a house in Pakistan?
Does solar work on a cloudy day?
Yes, at reduced output — panels respond to light, not direct sun, so an overcast day still produces meaningfully less rather than nothing. Heavy monsoon cloud can drop output to a fraction of a clear day. An on-grid system simply draws the difference from the grid, which is why sizing follows annual units rather than a peak day.
Do panels work better in summer?
Summer produces more because days are longer and the sun is higher, but panels themselves are less efficient when hot — output per degree of heating is on every datasheet as the temperature coefficient. So a cold bright winter morning can outperform a scorching afternoon per panel, even though the summer total is far higher.
What happens to the extra power if I have no net metering?
It is lost. Without a bidirectional meter there is no mechanism to record or credit export, so surplus simply flows away unrecorded. This is why a system sized well above your daytime consumption pays back slowly without net metering, and why usage patterns matter as much as system size.
Rather have it done?
Solar installation covers the survey, the panels, the mounting structure, DC and AC wiring, protection and commissioning. A 3kW on-grid system in Islamabad starts near PKR 350,000 complete, and the figure that matters is the one that includes structure and wiring rather than panels alone.
Solar panel supply and installation in Islamabad — prices and scope