With approximately one-kilowatt of energy hitting each square meter of sunlight earth each hour, it quickly becomes apparent that solar energy has great potential as an energy source. While these numbers can vary greatly based on weather conditions as well as the angle of the sun to the earth’s surface, many US business and residential buildings are incorporating solar technology to take advantage of this alternative resource. But where is this energy produced?
It Starts With Solar Panels
Energy from the sun is collected in silicone cells as it hits the panel surface. These silicone cells are made from either monocrystalline or polycrystalline components. Each panel consists of a glass surface that allows sunlight to penetrate the panel’s interior where the cells are housed. Each cell has a thin layer of silicone (polycrystalline) or highly refined silicone (monocrystalline) that shed electrons during this process.
Those electrons are negatively charged and help to create an electric current within the panel housing. This current is collected by the internal wiring. The amount of current generated depends upon the amount of sunlight hitting the cells as well as the efficiency of the solar panel’s components. Highly refined monocrystalline silicone is more efficient than polycrystalline cells.
Making Solar Energy Current Usable
The current generated by the collection process is Direct Current (DC), which needs to be converted to Alternating Current (AC), which is the type of current supplied to wall outlets from the power grid. This is done by a device called an inverter. Current generated by the panels travel down the wires that collect it and into these devices. Once the inverter converts it from DC to AC it is carried to an electrical panel and meter. From there, the AC energy moves through a home’s wiring to a wall outlet or is carried onto the power grid.
In most solar panel systems, a meter is used to generate the AC power in either a 120-volt supply or in a 240-volt supply that is used by heavy appliances such as washers and dryers. In the event that the energy collected does not meet a home’s needs, traditional electricity is still accessible from the power grid. Conversely, extra solar energy that is unused is transferred to the power grid.
Other Solar Panel Components
In order to keep the current stable and to prevent overloads to the system, a charge controller is installed. Solar panel systems connected to the power grid will also have a utility meter included in the system that the power company uses to monitor the energy generated. Solar power can also be stored in a battery form. A series of batteries, called a battery bank, store energy that can be used at a later time.
Other Solar Collectors
Thermal solar collectors gather heat instead of light from the sun and can be used for pools and water heaters. Concentrating collectors employ mirrors to focus sunlight onto collectors that generate solar heat.