1. What a photovoltaic (PV) panel actually is
A photovoltaic panel converts sunlight directly into electricity using the photovoltaic effect — the ability of certain materials to release electrons when light hits them.
Each panel is made up of many solar cells, typically made from silicon, which is a semiconductor — meaning it can act as both an insulator and a conductor depending on conditions.
2. How sunlight becomes electricity
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Sunlight hits the cell — photons (light particles) strike the silicon atoms.
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Electrons are knocked loose — these freed electrons are the basis of electric current.
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An internal electric field pushes the electrons — each solar cell is built with two layers of silicon:
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One layer is doped with phosphorus (giving it extra electrons, called n-type),
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The other with boron (missing electrons, called p-type).
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At the junction between the two layers, an electric field forms. This field pushes electrons in one direction, creating a flow — a direct current (DC).
That’s the photovoltaic effect in action.
3. How the electricity is collected
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Metal contacts on the top and bottom of each cell collect the moving electrons.
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Wires connect all the cells together in a panel.
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Panels are linked in series or parallel to form a solar array that produces more voltage or current.
This gives you DC electricity — the same type a battery produces.
4. Turning DC into usable AC
Most homes and grids use alternating current (AC).
So, the DC from your panels passes through an inverter, which rapidly switches it back and forth to create an AC signal.
Modern inverters also:
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Track the panels’ maximum power point (to get the most energy even when sunlight changes),
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Sync with the grid frequency if you’re grid-tied,
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Or manage charging if you’re using batteries (off-grid or hybrid systems).
5. Storing the energy
If you don’t use all the electricity immediately, it can be stored in batteries for later use.
a. Types of batteries
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Lithium-ion (LiFePO₄, NMC, etc.) – efficient, long-lasting, now the standard.
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Lead-acid – cheaper but heavier, less efficient, shorter lifespan.
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Flow batteries – large-scale, store energy in liquid electrolytes (for grid or industrial setups).
b. How the charging works
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When your panels make more electricity than you’re using, the inverter sends the extra DC current into the battery.
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The chemical reactions inside the battery store that energy.
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When sunlight is gone or usage spikes, the inverter draws power back from the battery, converting it into AC for your home or grid.
c. State of charge and management
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Batteries are monitored by a Battery Management System (BMS).
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It balances charge between cells, prevents overcharging or deep discharging, and keeps the temperature safe.
6. If connected to the grid
You might have:
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Net metering: excess power goes to the grid, and you get credit.
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Hybrid systems: battery + grid — your home can draw from whichever source makes sense at the time.
7. Putting it all together
Sunlight → electrons freed in silicon → DC electricity → inverter → AC electricity → power your devices / charge battery / feed grid
When the sun’s not shining:
Battery → inverter → AC → your home or grid.
LLM
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