Energy Matters Forums

[Andy Chee]

I was thinking that it might be possible to stimulate the solar panel inverter into producing power by using a small sinewave inverter operating from some back up batteries.??
Does anyone have any experience of this? How much power would be needed to stimulate the solar inverter? Surely this is not that different from operating two inverters in parallel.

Yes you can have battery back-up, but not quite in the convoluted parallel inverter wiring scheme you're thinking of.

There already exists on the market grid-connect inverters designed with a battery back-up input, however these are not standard equipment on the ordinary installations you typically see advertised by retailers.

[Gr11zzly]

On further investigation it seems the equipment to use is a POWER ROUTER. I think its an inverter that supplies either the Grid OR the house. Expensive though!! About $1/Watt

[SR76]

Do you mean by fooling the (bigger) grid-connect inverter into thinking that the grid is active, by providing a frequency to lock on to? If so... that's some clever thinking.

Here are the issues that spring to mind, though...

a) The user shouldn't be able to do this unless the grid is definitely isolated with some sort of secure switch

b) With a grid connect system, you can easily have the panels generate 3kW, and you can either switch everything on in the house and use 10kW or switch everything off and use 0W - the system doesn't mind about large and rapid changes in load. I would think that if the grid is isolated then the grid connect inverter might not like it so much!

[Andy Chee]

http://www.sma-australia.com.au/en_AU/p ... stems.html