Converting Sunlight to Electricity
A solar power system is a combination of solar modules wired in series to form an array designed to meet a predetermined electricity demand. Solar modules are comprised of multiple solar cells. The solar cells capture energy from sunlight and convert it into electricity. This conversion process occurs because of the special properties of the semi-conducting materials (silicon) from which solar cells are made. The silicon that makes up solar cells is a "semi-conductor" material having properties of both a metal and an insulator. N-type silicon ('N' is for negative) contains phosphorus, which produces more free electrons and is a better conductor than pure silicon. P-type silicon ('P' is for positive) contains boron which works to produce the positive charge in the electricity the modules produce. The two layers work together to produce electricity from sunlight. However, solar cells alone cannot produce usable electricity. They need to be connected with other system components that produce a specific electrical demand, often referred to as "load".
Play the video below for more detail on the photovoltaic process.
When the sun shines on the solar modules of a system, they produce direct current (DC) electricity. This electricity is transmitted from the modules to an electronic inverter which converts the DC electricity to alternating current (AC). The AC electricity is then transmitted to the home or building's distribution system to supply electric power as needed throughout daylight hours. The excess electricity is diverted out to the power grid causing the electric meter to spin backwards and produce credits toward the electric utility bill. During non-sun hours, utility power provides the electricity needed.
