A solar panel converts sunlight directly into electricity through the photovoltaic effect: photons knock electrons loose inside a silicon cell, a built-in electric field pushes them in one direction, and that flow is direct current (DC). An inverter then converts that DC into the 230V, 50Hz alternating current (AC) your home and the grid use. Understanding both halves — the panel and the inverter — explains almost everything about how a modern solar system behaves.
<div class="tldr" style="border:1px solid #cbd5e1;background:#f8fafc;padding:16px 20px;border-radius:8px;margin:24px 0;"> <strong>Quick answer</strong> <ul> <li>Silicon cells generate DC current via the photovoltaic effect at the p-n junction.</li> <li>An inverter uses high-speed switching (pulse-width modulation) to synthesise grid-matched AC.</li> <li>Panels keep working under cloud — typically 10–25% of rated output on heavy overcast.</li> <li>MPPT and grid synchronisation run continuously, many times per second.</li> </ul> </div>
A solar cell is a wafer of silicon deliberately "doped" with trace elements to create two layers. The upper layer is doped with phosphorus, giving it a surplus of free electrons (n-type silicon). The layer beneath is doped with boron, leaving it short of electrons — full of "holes" (p-type silicon).
Where these layers meet is the p-n junction, the single most important part of the cell. Electrons from the n-type layer diffuse across into the p-type holes, creating a small built-in electric field ready to push electrons in one direction the moment it gets a reason to.
That reason is sunlight. Photons strike the silicon and, if they carry enough energy, knock an electron loose, leaving a hole — the photovoltaic effect itself. Because this happens near the junction, the electric field grabs the freed electron and pushes it toward the n-type layer while the hole goes the other way. Do this to billions of photons per second and you get a continuous, one-directional flow of electrons — an electric current — collected by fine silver busbars printed on the cell.
This is direct current (DC): it flows in one constant direction, like a battery's. Your home and the grid run on alternating current (AC), which is where the inverter takes over.
Because the photovoltaic effect responds to photons, not heat or direct beam sunlight specifically, panels keep generating in overcast conditions — just at reduced output. Clouds scatter and diffuse sunlight rather than blocking it outright, so cells still receive a meaningful number of photons, typically producing somewhere in the order of 10–25% of rated capacity on heavily overcast days, more on light cloud. It's a dimmer switch, not an on/off switch.
A single solar cell produces less than a volt. Panels wire dozens of cells in series to build usable voltage, and multiple panels group into "strings" feeding the inverter. The inverter's core job is converting that DC into the 230V, 50Hz AC that Australian homes and the grid use.
It does this through switching. Inside the inverter, banks of semiconductor switches (typically IGBTs or MOSFETs) turn the DC input on and off thousands of times per second in a precisely controlled pattern — pulse-width modulation. By varying the width of these pulses in a specific rhythm, the inverter synthesises a smooth sine wave of AC, mimicking exactly the waveform the grid produces.
Before conversion happens, the inverter constantly adjusts the electrical load it presents to the panels, searching for the voltage and current combination that extracts the most power available at that instant — Maximum Power Point Tracking. Panel output shifts continuously with sunlight, temperature and shading, so this is a live optimisation loop running many times per second, not a one-off calibration.
Before the inverter can push power into your switchboard and out to the grid, it has to match the grid's frequency and phase almost exactly — Australian mains runs at 50Hz. Inverters do this automatically and continuously, and they must disconnect instantly if grid power fails — a safety function called anti-islanding, which stops your system backfeeding power into lines that network technicians may be working on during an outage.
Once converted to AC, your solar output takes the path of least resistance. It's consumed first by whatever's running in your home right now — appliances, lighting, air conditioning. Anything unused is then exported to the grid through your meter, charged into a battery if you have one, or occasionally curtailed. Which happens, and in what order, is governed by the inverter's internal logic — and in hybrid systems this gets considerably more sophisticated (see How a Hybrid Inverter Works).
A panel generating perfectly at 1pm is only genuinely valuable if that power is used, stored, or fairly compensated — which is exactly why batteries, hybrid inverters and time-of-use tariffs matter as much as the panels themselves.
No. Without photons striking the cells there's no current, which is why storing daytime surplus in a battery is what covers evening and overnight use.
Panels produce DC. The inverter converts it to the AC your home and grid use.
Silicon's electrical output declines marginally as cell temperature rises, so a cool, bright day can outperform a very hot, cloudless one.
To see what a correctly sized solar system would generate on your specific roof, compare the figures with Blue Energy Solar's free solar calculator, or call 0421 458 217.
