"Dirty" feed in retrofit

R

rthorntn

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Hi

I'm in NSW and have an "eclectic" setup with two "separate" inverters, only one feed-in exports to the grid, unfortunately the "export" inverter doesn't have a battery attached.

My off-grid setup has 19.2kwh of (ten Zenaji "go Aussie" Aeon LTO) batteries attached.

I can switch my panels between inverters (Latronics SATS) so I can choose when I export.

I want to be able to export from battery and a friend suggested using a rectifier to feed one of the DC solar inputs on my feed-in inverter, so I rectify my off-grid inverters AC to like 300v ish DC and send that...any issues with this, if it makes sense does anyone know of a suitable rectifier that can do at least 2kw of output and allow me to vary the output so I can export 0.5kw or 1kw kind of thing?

Thanks.
Richard
 
If you can switch panels between them, then you should be able to connect a battery to the inputs as well. DC is DC, doesn't matter if it's solar or battery. Unless your panels have micro-inverters installed, which is AC, or high frequency DC

I would not recommend using a rectifier to go from one inverter into the other one. This could cause other issues. not to mention the high voltage issues.
Remember, AC voltage isn't actually 240V, that's just the RMS. The upper voltage range would be around 340VAC. Can your inverter handle 350+VDC as a source input? Not to mention it would be choppy, even with a full-bridge rectifier. You would also need to have high voltage capacitors to smooth the output.

Problem with all this is it is highly inefficient. You would be taking Solar/Battery voltage and converting to AC, and then converting it back to DC to just convert it back to AC again. With each conversion possibly loosing about at least 10% during the conversion.
In the end you would actually be wasting more energy to heat/resistance than you'd make from exporting to the grid.
 
Korishan said:
If you can switch panels between them, then you should be able to connect a battery to the inputs as well. DC is DC, doesn't matter if it's solar or battery. Unless your panels have micro-inverters installed, which is AC, or high frequency DC

I would not recommend using a rectifier to go from one inverter into the other one. This could cause other issues. not to mention the high voltage issues.
Remember, AC voltage isn't actually 240V, that's just the RMS. The upper voltage range would be around 340VAC. Can your inverter handle 350+VDC as a source input? Not to mention it would be choppy, even with a full-bridge rectifier. You would also need to have high voltage capacitors to smooth the output.

Problem with all this is it is highly inefficient. You would be taking Solar/Battery voltage and converting to AC, and then converting it back to DC to just convert it back to AC again. With each conversion possibly loosing about at least 10% during the conversion.
In the end you would actually be wasting more energy to heat/resistance than you'd make from exporting to the grid.
Click to expand...
Thanks, my battery system is 48v though, no way to connect that to my feed-in inverter.

Are there any (under $2000 AUD) grid-tie inverters that support any 48v battery (not just the inverter manufacturers own battery)?
 
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