Solar power for your home
The basic components of a solar power system and how they work
There are three types of solar power systems that you might consider installing on your home being:
- A grid connect solar system;
- A hybrid solar system, being a grid connect solar power system that is connected to the grid but also has solar batteries to provide power storage; and
- An offgrid solar power system.
This page shows the basics of a grid connect solar power system.
However, before we do that it is important that we distinguish between two different types of solar energy being solar pv (or photovoltaic solar) and solar thermal.
Solar pv is where the irradiation in sunlight is used to stimulate the flow of electrons in a semiconductor to create a flow of electricity. So in this instance it is the irradiation is sunlight that is useful, not the heat. In the case of solar thermal then it is the heat produced by the sun that is used. Solar thermal is mainly used to heat hot water and this is by far it's most common application.
Components of a grid connect solar power system
Solar cells in the solar panels mounted on your roof convert sunlight directly into DC power.
The cells contain semiconductors and the irradiation in sunlight stimulates the movement of electrons accross these semiconductors.
A component called a solar inverter converts this DC power into AC power that can be used by your house or business. The system is interconnected with your utility or grid electricity supply. This is why it is called a grid connect system. During the day, if your solar system produces more electricity than you are using, your utility may allow net metering, in which case you get a credit for the amount of kwh (kilowatt hours) of power that you feed back into the grid. You can find out more about the net metering offered by your power company in by searching our incentives and rebates for home solar power page for your state.
Your electricity company continues to provide power as usual at night and during the day when your electricity demand exceeds that produced by your solar power system. A solar inverter is a device that transforms DC battery or solar panel voltage into mains type AC power; suitable for use by regular appliances. A solar inverter is an integral part of a system, but attention to this aspect is often overlooked. You can have the best solar panels available, but if your solar inverter is of poor quality, overall system performance can be greatly impacted.
Here is a diagram that shows how it works: