03-15-10, 02:43 PM | #1 |
Lex Parsimoniae
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Off-the-grid with grid-tie inverter?
http://ecorenovator.org/forum/applia...-inverter.html http://ecorenovator.org/forum/solar-...-inverter.html If this configuration would actually Start up, it seems like the 12VDC-to-120VAC inverter would be using very little from the battery, since the grid-tie inverter would try to make it's voltage just a tad higher.. Anyways, I was thinking this might be the lowest cost way to DIY off-grid power.. If it did work, you could stack the little 300 watt grid-tie (or Enphase) GTIs and get some nice power-point-tracking from each panel.. Comments please: Thanks, Rich |
03-15-10, 03:10 PM | #2 |
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It looks interesting. But, in order for this setup to be legal, you'd still need some sort of disconnect going to your service panel. Or, are you thinking the grid tie will take care of that?
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03-15-10, 03:24 PM | #3 |
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It would be cheaper to just use a regular inverter.
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03-15-10, 03:26 PM | #4 |
Lex Parsimoniae
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I'm thinking more along the lines of taking a couple of 200 watt panels camping with you,
or to some remote cabin site.. The idea here, is to use the much cheaper grid-tie micro-inverters, off-the-grid. Or, maybe you have to do some light construction work, way out in the boondocks? Haul out some 220 watt panels, a little power-box to hook up to your 12v truck battery, connect up some panels and you could run small power tools and charge up the rechargeable power tools on site. (If the sun stayed out). Would not replace a gas generator, but might be good if you didn't need 5KW.. I'm pretty sure that PV is going to get a lot cheaper, pretty soon.. |
03-15-10, 03:31 PM | #5 |
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03-15-10, 03:40 PM | #6 |
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If this setup is completely off grid why do you even need the grid tie inverter?
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03-15-10, 06:39 PM | #7 |
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Because, they are compatible with many PV panels, cheap &,
they are scalable when used off-grid or with a grid-tie system.. Scalability is important if you only need (or can only only afford) a few hundred watts. You can meet that need at a reasonable price with micro-inverters. |
03-16-10, 06:30 AM | #8 |
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I was under the impression that grid tie inverters need to be connected to the grid to work.
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03-16-10, 07:56 AM | #9 |
Lex Parsimoniae
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Leo, Do you Know what the Gird is? Do you want to know the truth?
The answer, the number 60. As in 60 Hz. The voltage is 120 or 230. So, as I've said before, if you can trick the GTI into thinking it's connected to the grid, then it will work.. That's why the 12Vdc-to-120Vac inverter needs to have a pretty clean output. I'm pretty sure that my little modified-sine-wave inverter would NOT work. But I'll bet an old UPS (computer back-up Un-interruptable Power Supply) would work just fine. And, it has it's own LA pack! |
03-16-10, 08:30 AM | #10 |
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I suppose that makes some sense. It just seems a bit more complicated than it needs to be.
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