☀️Solar Energy

How Does Solar Energy Actually Work?

Solar panels generate electricity through the photovoltaic effect — photons from sunlight knock electrons loose from semiconductor atoms, creating a direct current (DC) that inverters convert to alternating current (AC) for home and grid use. A standard silicon solar cell produces approximately 0.5 to 0.6 volts. Cells are wired in series to form modules, and modules are connected into arrays that produce the voltage needed for grid-tied inverters.

Monocrystalline silicon panels dominate the residential market with efficiencies of 20-23 percent for commercial modules. Tandem perovskite-silicon cells are an emerging technology. For a complete technical deep-dive, read our solar energy systems complete guide.

What Size Solar System Do I Need?

Average US households consume 10,000-15,000 kWh annually, requiring a 6-10 kW solar array to offset 100 percent of usage. A 7 kW system in Phoenix produces approximately 12,600 kWh/year. In Seattle, the same system produces about 8,400 kWh. Roof orientation changes output, so use the solar panel installation guide before sizing.

How Much Does Solar Cost?

Residential solar costs $2.80-$3.50 per watt installed before incentives. A 7 kW system costs $19,600-$24,500 before the 30 percent federal ITC. For solar-plus-storage economics, see the home battery storage guide.

What Is the Next Solar Decision?

Compare roof fit, expected production, utility rates, incentives, and service access before comparing panel brands. The next useful number depends more on the local site than on a headline efficiency claim.