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Renewable Energy > Solar

Sunlight - or solar energy - has been gaining momentum as a source of electricity. Most likely you’ve seen solar-powered calculators or solar panels on rooftops for heating homes. This same solar power can also be used to generate larger amounts of electricity.

Instead of using fossil fuels, solar power technologies use photovoltaic (PV) panels to convert sunlight directly into electricity. This process involves no moving parts. PV systems can be very small (using only a few panels) or many panels can be connected together to construct large systems.

The panels are made of semiconducting materials similar to those used in computer chips. When sunlight is absorbed by these materials, the solar energy knocks electrons loose from their atoms, allowing the electrons to flow through the material to produce electricity. This process of converting light (photons) to electricity (voltage) is called the photovoltaic (PV) effect.

Solar cells are typically combined into modules that hold about 40 cells; about 10 of these modules are mounted in PV arrays that can measure up to several meters on a side. These flat-plate PV arrays can be mounted at a fixed angle facing south, or they can be mounted on a tracking device that follows the sun, allowing them to capture the most sunlight over the course of a day. About 10 to 20 PV arrays can provide enough power for a household.

Because the electricity produced by PV arrays is in the form of direct current, if the electricity is supplied to the electric power grid, the arrays need to be coupled to an inverter which changes the direct current into alternating current. Once converted to the appropriate voltage and frequency, the electricity can be supplied to the electric grid.

Solar Power In-depth
Click on a link below to find out more about solar technologies.

Documents/Articles
Renewable Energy: An Overview - courtesy EERE (PDF)
Get Your Power From the Sun - A Consumers Guide - courtesy EERE (PDF)
Heat Your Water with the Sun - A Consumers Guide - courtesy EERE (PDF)
Small solar electric systems - courtesy EERE
NC GreenPower application for small solar PV and wind (10 kW and under)

Resources
North Carolina Incentives for Renewable Energy - courtesy DSIRE
Find a renewable energy professional in your area - N.C. Solar Center
Renewable Energy Technology Diploma Series - N.C. Solar Center (PDF)