Solar electric systems, also known as photovoltaic or PV systems, convert sunlight into electrical energy in order to meet some or all of the energy demand in a home, business or community. Let’s take a look at how the components of a solar energy system generate electricity.
The Building Blocks of Solar Power
A photovoltaic cell, also known as a PV or solar cell, is the basic building block of a solar electric system. These solar cells convert light energy into electrical energy through what is known as the photoelectric effect.
When light (in the form of a photon) strikes the special semiconductor material in a solar cell, it knocks electrons loose from that material. Electrical conductors attached to the positive and negative sides of the PV cell form an electrical circuit, capturing those electrons in the form of an electric current. A special property in the solar cell known as the built-in electric field provides a force which drives the current through an external load, such as a light bulb.
An individual solar cell typically produces 1 or 2 watts of power, which isn’t very much. And it doesn’t capture all the photons that hit it – only about 14% of the light that hits a solar cell is absorbed (the remaining photons will be reflected or pass right through the solar cell). So, we connect the photovoltaic cells into larger units called modules, or solar panels, which are then connected into solar arrays that are sized to meet a variety of residential, commercial, or community solar energy needs.
What Other Components Are Included in a Solar Energy System?
In addition to the solar panels, a solar electric system will include mounts that tilt the solar array toward the sun and components called solar inverters that convert the solar panels’ direct current (DC) electricity into the alternating current (AC) electricity used in homes and businesses. Some solar energy systems also use batteries to store solar electricity for later use (for example, at night).