The Solar Array
One of the great things about solar power is that there are no moving parts in a PV array.
A PV array is what you normally see on a roof. It’s a collection of solar panels, which are comprised of solar cells (usually made of silicon) that sit in the sun to harvest energy. When a photon from the sun hits a cell, it knocks loose an electron from the silicon atoms that make up the cell. There are wires connected to the solar cell that collect these roaming electrons. The wires are connected to other cells and all of the cells together make a solar panel. One panel is connected to the next in a combination of series and parallel connections known as a “string.” All of these connections of cells, panels, and strings are considered a solar PV array.
The Solar Inverter
These connections attach to wiring that comes down from the roof in one or more conduits.
The conduit delivers the wire to an inverter. The inverter is usually located near your main service panel in a garage or on an exterior wall. The inverter converts the DC electricity of the solar array to AC electricity so it can be used in your house. In most cases it also has an display that allows you to read data about how your system is performing at a given moment and over time.
From the inverter, AC electricity travels through additional wiring and conduit to a production meter and in some cases a utility disconnect.
The production meter is there to measure all of the solar power your system produces before it’s consumed by loads in the house or traded with the utility. This is an important step because Washington State Production Incentive is paid based on the data recorded by this meter. Some utilities in Oregon don’t require a production meter.
Main Service Panel
The electricity flows from the production meter through more wiring and conduit to your main service panel.
In most cases, we install a solar breaker at the bottom of your main service panel (aka electrical panel or breaker panel). This connection to your service panel is what makes it possible to power your home with solar. The solar electricity flows first to any loads running in the house, such as a refrigerator, TV, lights, or anything else that might be consuming power while the sun is shining.
If you only have a few loads consuming your solar power and have excess power being produced, the electricity is pushed out to the world at large through your net meter.
A net meter is also considered your “Utility Billing Meter”. Here in Washington State and Oregon, your utility allows you to spin your net meter backwards and generate a credit for your excess solar power on your bill. These credits tend to build up quickly in the summer months and cashed-in during the less-sunny winter months.
One other component you might want to consider adding to your PV system is a data monitoring device.
Monitoring devices collect data from the inverter and present it visually through charts, graphs, or other animations. Most monitoring systems also allow you view your data online, and some even track the overall energy use within the home. Monitoring systems illustrate how solar equipment performs under various conditions, and can be a great motivator for conserving energy overall.
And voilà, your home generates it’s own solar power!