A grid tied solar system in Arizona is connected to the electrical grid. This type of system allows you to sell excess electricity back to the utility company. Also, when the home requires more power than the solar panel system can provide, electricity from the grid is automatically imported. Grid tied systems are usually less expensive than off-grid systems, and they are easier to maintain.
Benefits of a Grid Tied Solar System
Grid tied solar systems are the most common type of solar panel system.
The main advantage of grid tied solar systems in Arizona is they allow homeowners to save money on their electricity. Because, the monthly cost of the solar loan or lease, plus the new utility bill, is lower than the monthly cost of electricity before solar.
Being able to supplement your grid tied solar system with power from the utility means that you can have a smaller and less expensive system. Also, most utility companies allow homeowners to sell surplus electricity back to the grid. Thus, the utility grid acts as a battery, because energy sent to the grid then offsets the customer’s utility bill. This process of exporting surplus power to the utility grid in return for bill credits is called Net Metering.
Another advantage of a grid tied system is that you do not need batteries to store the electricity that your solar panels produce. Batteries are a relatively newer technology, and they are still quite expensive. Also, the storage capacity of consumer solar batteries is still quite small. A single consumer solar battery cannot power large appliances like the air conditioner. Actually, to keep the air conditioner running throughout the day, at least two solar batteries will be needed. Batteries have a starting cost of around $12,000, so adding two or more batteries to a system becomes expensive fast. Typically, off-grid solar systems are double or triple the cost of grid tied solar systems.
Seasonal Changes of a Grid Tied Solar System
The graph below shows the typical relationship between energy consumption and solar production for a grid tied solar system in the Phoenix, Arizona area. Phoenix is unique because temperatures in the summer can rise up to 120 degrees. So, homes in the Phoenix area must run their air conditioners all day long in the summer for people to be comfortable inside. Air conditioners use the most electricity out all the typical large appliances in a home.
As you can see from the graph, the home consumes more electricity in the summer than the grid tied solar system produces. Thus, the home must draw electricity from the utility grid during the day to meet the electricity demand. Further, the home must draw electricity from the grid at night when the solar system is not producing. Due to this, customers will have to pay the utility company in the summer months for the electricity purchased.
However, in the winter, the grid tied solar system produces far more electricity than the home uses. Because, the air conditioner does not run in the winter in the Phoenix area. Most utility companies allow customers to “bank” the electricity surplus. This means that electricity “credits” are built up in the winter and then used in the summer when the home needs electricity from the grid. Customers do not have to pay for these “credits” because their own grid tied solar system produced them earlier in the year. So, these “credits” lower the amount of the utility bills in the summer.
Components of a Grid Tied Solar System
Grid tied solar systems are relatively simple compared to off-grid solar systems. This is because there is no on-site storage equipment and less wiring to deal with. Here are the components of grid tied solar systems:
- Solar Panels: A typical home will require between 10 to 30 solar panels. This depends on how the utility company bills with solar and the energy use of the occupants in the home.
- Inverter: Since the solar panels produce DC electricity, and your home uses AC electricity, the inverters must be present to perform the conversion. These are grid tied inverters, and they communicate with the utility grid. They allow the home to import power from the grid in addition to exporting power to the grid. Some systems have string inverters, which is a single inverter on the side of the house. Other systems have microinverters, which are tiny inverters installed under each solar panel.
- Racking System: The racking system is mounted to the roof of the home, then the solar panels are attached to the racking system. They also provide space between the roof and the solar panels, which is necessary for ventilation.
- Wiring: This connects the solar panels together and sends electricity to the home’s electrical box.
- Net Meter: A second utility meter is installed on every home with solar for the purpose of measuring the amount of energy exported to the grid.
For more information on how solar panels work, visit our page on How Do House Solar Panels Work?