Q: What is the minimum amount of amp hours needed for Outback Inverter?

[foo]

This would be for a Grid Tied application.

I have Outback Power Vented VFXR3524A 3500W 24VDC Hybrid Series Sine Wave Inverter.
3.5kW of solar panels.

I have two questions:
What is the minimum amount of battery required to keep the Inverter running? I am assuming there's a minimum amount of battery required to keep the inverter from bogging down, being interrupted too fast and too often.

I was wondering if there was a way to not use batteries with the Outback inverter for Grid Tied Solar. I saw an article about using supercaps instead of batteries. Would there be a way to keep the Grid Tied application working without using batteries in some way using capacitors?

Thanks in advance for any info.

[Mike90250]

capacitors are rated for power, from 0v - 50v In use with an inverter, only usage from 20-28v is allowed, so with a cap, you buy capacity you can never harvest (0-20v)
and they (even super caps) would only run a inverter for a second or two, even if solar was charging.

There are special GT inverters that do run strictly from solar pv

[foo]

capacitors are rated for power, from 0v - 50v In use with an inverter, only usage from 20-28v is allowed, so with a cap, you buy capacity you can never harvest (0-20v)
and they (even super caps) would only run a inverter for a second or two, even if solar was charging.

There are special GT inverters that do run strictly from solar pv

I tried to reword the second question. I realized it seemed like I was asking if I could use a capacitor to store the power and then harvest it when needed. What I meant to ask is, is there a way to simply perform the inversion process(via the inverter) of solar to a/c without storing it to battery?

I am guessing a battery is used for fluctuations in power input. So there may be no way around it. But I wondered how much of this excess the inverter actually needs to keep itself happy. Can something else help with this?

[Mike90250]

in a word - no.

generally, in a 24v system, you need 100A of battery for every 1kw of output. caps cannot meet this requirement.

[jflorey2]

What is the minimum amount of battery required to keep the Inverter running?

For the Radian it's 400AH. For the GVFX series it's not listed, but an example goes as low as 85ah for a 24V inverter.

I am assuming there's a minimum amount of battery required to keep the inverter from bogging down, being interrupted too fast and too often.

Depends on a great many things, primarily your loads.

I was wondering if there was a way to not use batteries with the Outback inverter for Grid Tied Solar. I saw an article about using supercaps instead of batteries. Would there be a way to keep the Grid Tied application working without using batteries in some way using capacitors?

Not really; you'd need a very large cap bank (read - thousands of $$$) to get enough capacity to do a useful system, even if you didn't want to do a 'regular' battery system. The control loops in those inverters are slow, and thus you can't get away with a small capacitance; there needs to be enough energy to ride through control system delays.

What I meant to ask is, is there a way to simply perform the inversion process(via the inverter) of solar to a/c without storing it to battery?

Sure; use a grid tie inverter. If you want to do both, Outback is soon coming out with the Skybox - a string inverter that will work with or without batteries.

[foo]

Thanks for the info both of ya.

Will Skybox work with 24v or 48v solar arrays?

[jflorey2]

Will Skybox work with 24v or 48v solar arrays?

Skybox is a string inverter and will work with high voltage strings. Generally 125-600V, but the final specs aren't out yet.