EcoRenovator - View Single Post - Off-the-grid with grid-tie inverter?

marzero0 · 10-26-11, 05:14 PM

Hi Xringe, i had read all posts.. Thanks for your investigation and info!

First, excuse me for my not very good english.

I think what happened to your chinese inverter is that the power of the TGI was "regenerated" for the inverter. In other words, current went into the inverter, so the "capacitor" started to acumulate that current and so the voltage was increasing.

What a TGI do is give current at the same frecuency of the voltage of the grid. This means, you can see the TGI as a current source, it doesnt modifies the voltage at all. The current goes in phase with the grid voltage, that means the power is generated (source) and its not consuming.

I think you can use a UPS instead a expensive true sinusoidal inverter. The UPS gives a PMW voltage, this means it have less harmonics than the inverter (is more clean) .

Now im working in a similar idea. The problem of this off-the-grid is when you dont have more energy in your batteries or the solar panel cant give you energy (the night) or simply your system dont have the power to give a load that it needs (a stove of 3000 W for an example). So my idea is to take a system that gives the energy of the PV panels and the batteries, and then if its not enough, it takes energy from the grid. This means a off-the-grid with back-up-grid. All this made with the same equipment (chinese TGI and a UPS). Uhm! in my country send energy to the grid is just give it away (no net mettering for now), thats why the-off-grid is a ver good option. Ill be posting a schematic of what im thinking!

Well thats it, thanks again for sharing your investigation!

10-26-11, 05:14 PM	#53
marzero0 Lurking Renovator Join Date: Oct 2011 Location: chile Posts: 4 Thanks: 0 Thanked 0 Times in 0 Posts	Off grid Hi Xringe, i had read all posts.. Thanks for your investigation and info! First, excuse me for my not very good english. I think what happened to your chinese inverter is that the power of the TGI was "regenerated" for the inverter. In other words, current went into the inverter, so the "capacitor" started to acumulate that current and so the voltage was increasing. What a TGI do is give current at the same frecuency of the voltage of the grid. This means, you can see the TGI as a current source, it doesnt modifies the voltage at all. The current goes in phase with the grid voltage, that means the power is generated (source) and its not consuming. I think you can use a UPS instead a expensive true sinusoidal inverter. The UPS gives a PMW voltage, this means it have less harmonics than the inverter (is more clean) . Now im working in a similar idea. The problem of this off-the-grid is when you dont have more energy in your batteries or the solar panel cant give you energy (the night) or simply your system dont have the power to give a load that it needs (a stove of 3000 W for an example). So my idea is to take a system that gives the energy of the PV panels and the batteries, and then if its not enough, it takes energy from the grid. This means a off-the-grid with back-up-grid. All this made with the same equipment (chinese TGI and a UPS). Uhm! in my country send energy to the grid is just give it away (no net mettering for now), thats why the-off-grid is a ver good option. Ill be posting a schematic of what im thinking! Well thats it, thanks again for sharing your investigation!