Grid Tie (Tied) Inverters are an attractive way to use solar power to reduce electric bills. They work by backfeeding A/C power into the electrical service wiring or via a standard wall outlet, causing a slightly higher line voltage. In a nutshell, this causes the Grid Tie Inverter’s power to be used up first by local appliances, thereby reducing overall energy usage from the electrical grid.
Types of Grid Tie Inverters
There are 2 main types – hard wired and plug in.
A hard wired Grid Tie Inverter (GTI) usually is installed by a licensed electrician and manually wired into the residential load center or breaker panel and is permanently installed.
A plug in (plugin) grid tie inverter usually has an IEC electrical connector on it that enables the solar inverter to be plugged directly into an AC wall outlet in a typical home. They use a standard power cord for that purpose.
Some users just wire an A/C power cord to a hard wire inverter and call it a day.
Issues specific to plug in GTIs
Before continuing, I must say plug-in grid tie inverters might be frowned upon by local regulations or codes, so it’s important to look into this angle. Also there are inherent risks in backfeeding power into an AC electrical outlet that was never designed for that.
The most dangerous part of a plug in GTI is the user can easily defeat the circuit breaker in his homes electrical plant and start a fire. Electrical fires are a common cause of home destruction and one of the most costly repairs a typical building could require.
For this reason it’s important to do proper research and understand all safety aspects before buying let alone trying to use a plugin grid tie inverter.
The bottom line is that if the plugin grid tie inverter is used in the wrong way, it can absolutely start a fire and is absolutely dangerous. In the right hands, the educated and informed DIY solar power enthusiast should be able to safely operate a plugin GTI without any more risk than a standard hard wire GTI.
If you want to learn more about the safety risks involved with using a Plugin Grid Tie Inverter, I made a video explaining the safety problems inherent in the plug-in design. If you are interested it is posted below. Thanks for reading! DD