Author Topic: Grid tie inverter question  (Read 4054 times)

sardonicus

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Grid tie inverter question
« on: September 22, 2013, 10:31:35 PM »
Very new to the whole solar power thing, doing some DIY projects to get more familiar with some things - just to run my greenhouse for now. I am having a difficult time wrapping my head around how a grid tie inverter puts energy back onto the grid. Or really how one is wired up at all to feed the house. I have been watching a few videos on people installing grid tie inverters and it seems like everyone is doing something different. Ultimately I will probably have a professional do the install for the house when I can do that later but I still want to understand things better.

In case my questions got lost in the drivel - I am wanting to know how you wire a grid tie inverter to put power on the existing house circuit and I am wanting to know how this puts energy back onto the grid.

MJLorton

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Re: Grid tie inverter question
« Reply #1 on: September 25, 2013, 12:15:39 PM »
Hello...and thanks for the post.

I hope to do a video demonstrating this in the future so that it is understandable to for the man in the street.

The installation of the grid tie inverter itself is very straight forward (accounting for safety and good practice - fuses, disconnects, etc.).

There's a DC input from the solar panels and an AC output that connects to the house AC circuit through a breaker in the house DB board.

This is where a qualified electrician needs to get involved that understands these systems...and I came across a few that still did not know how to hook these systems up correctly....and I should not be in a position to say this as I'm not an electrician.

I don't want to go into to much more detail as this is not my area of expertise but the grid tie feed can be connected as an alternate power feed through a transfer switch or in conjunction with the power company feed. It can then feed the house and then push back to the grid (hopefully) through some form of legal net metering  system.

One of the most important things to get right here (with any alternate energy source) is that the single (or multiple physically linked) MAINS breaker kills ALL power to the household circuits in case of emergency.

The grid tie will feed the house demand / load first as that is the circuit it is on. If there is excess power from the grid tie it will be "pushed" out onto the grid as there is demand there...Ohms Law.
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