How a Residential Solar System Works

Here we will explain how a residential solar system works in the Phoenix, Arizona area.

• Your home uses alternating current (AC) electricity.
• The inverter converts the DC electricity from your solar system to AC electricity so that your home can use the energy.
• Modern solar systems either have a string connected setup using one inverter or parallel connected setup using microinverters. When microinverters are used, each panel has a smaller inverter installed underneath it that converts the energy that panel creates.
• The advantages of microinverters are:
  • They allow each solar panel to work independently, so that shade, damage, or debris on one panel will not affect the remaining panels in the system. With a single inverter setup, shade or debris on one panel can reduce the output of the entire solar system.
  • They allow each individual panel to be monitored by the homeowner or the solar installation company, which allows people to detect, repair, and replace underperforming panels.
  • They are more reliable, especially in the extreme heat weather of Phoenix, Arizona.
  • They have longer 25-year warranties as opposed to the 5 or 10-year warranties on single string inverters.

Once the AC electricity leaves the inverters, it then travels to the electrical box and is sent into your home to power the appliances the same way electricity from the grid does.

• Solar batteries store energy produced by the solar panels that is not immediately used in the home.
• The energy stored in the battery can then be used at night-time when the solar panels are not generating any electricity. This can lead to a cost savings because the home is being powered by stored energy that is free compared to buying energy from the utility company at night.
• Batteries are also deployed to lower the amount of energy taken from the utility grid during on-peak times when utilities have inflated time-of-use charges and demand charges. This can lead to a cost savings because the homeowner will use more stored energy and less energy from the grid with inflated prices during on-peak times. Further, a battery can also lower the peak demand in on-peak times by drawing less power from the grid, which results in savings.
• Currently, batteries are often too expensive, and a battery purchase can prevent the homeowner from saving money by switching to solar. Current batteries also have a relatively low capacity for energy storage. But just like computer hard drives which have significantly dropped in price and have exponentially increased storage size, so will solar batteries. In the future, batteries will likely be on every home that has solar.
• An added benefit of solar batteries is that it can power the home when the grid goes down. Without a battery, a grid failure stops the solar system from producing energy as a safety measure to prevent electricity being sent to the grid and harming utility line workers fixing the issues.

• Power generated at power plants and rooftop solar systems travels through a complex system of electricity substations, transformers, and power lines. This system is often called the “grid”.
• Every solar system in the Phoenix, Arizona must be connected to the grid according to law. This ensures that the home still will get electricity if the solar system goes down. Also, the present technology of solar panels and batteries is not quite advanced enough to allow an affordable “off-the-grid” solar system. And “off-the-grid” system can be built, but its price is out of reach from most consumers and it will end up costing more than staying with the utility company. Further, it is often necessary, especially at night and in the summertime, for homes to draw power from the grid to maintain consistent electricity in the home.

If you any more questions about how residential solar systems work, please feel free to call us at (602) 753-0560.