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How do solar panels (cells) generate electricity?

Figure 6 - Solar Panel Cutaway

Figure 6 - Solar Panel Cutaway

 

Photocells (photovoltaic or “PV”) can be thought of as a direct current (DC) generator or charger powered by the sun.

When light photons of sufficient energy strike a solar cell, they knock electrons free in the silicon crystal structure forcing them through an external circuit (battery or direct DC load), and then returning them to the other side of the solar cell to start the process all over again. The voltage output from a single crystalline solar cell is about ½ Volt with an amp output that is directly proportional to the cell's surface area (approximately 7 amps for a 6 inch square multi-crystalline solar cell). In typical solar module there will be 30 to 36 cells connected in series. This produces a solar module with a 12V nominal output (17V peak output) that can then be wired in series and/or parallel with other solar modules to form a complete solar array capable of charging a 12, 24 or 48 volt battery bank.

General Lead Acid Battery Description
General Lead Acid Battery Applications
General Lead Acid Battery Types
General Lead Acid Battery Chemistry
Discover® Sealed Valve Regulated Lead Acid Batteries
Discover® Deep Cycle AGM Battery
Discover®700 Series Dry Cell Battery
Discover® EV Traction Dry Cell Battery
General Benefits and Features of Discover Valve Regulated Lead Acid (VRLA) Technology
Sales Channels for Discover Battery Technologies
Things to question when making a battery buying decision
What to consider when buying a deep cycle battery
Information gathering before buying batteries
Calculating cost to own when purchasing batteries
Safety First
Safety and Productivity
When working with batteries
When handling battery acid
When installing or replacing batteries
When booster cables are used
Danger of exploding batteries
Warning and warning labels
Parallel connections for sophisticated users and installers
Parallel connections for unsophisticated users and installers
Charging
When charging batteries
Selecting a charger
General charging information for AGM and GEL batteries
GEL battery charging
AGM battery charging
Equalizing (Flooded batteries only)
Discharging
Typical self-discharge of VRLA batteries at different temperatures
Typical self-discharge of high quality deep cycle flooded batteries at different temperatures
How much will a system cost for my 2000 square foot home?
Can I use all of my normal 120/240 VAC appliances?
What components do I need for a grid-tie system?
What components do I need for a complete solar system?
What type of solar module mounting structure should I use?
Where should I mount the solar modules and what direction should I face them?
Should I set my system’s battery bank up at 12, 24 or 48 VDC?
Should I wire my home for AC or DC loads?
Can I use PV to heat water or for space heating?
How do solar panels (cells) generate electricity?
Will solar work in my location?
Tables & Figures