Inverters

[Georgie Porgie]

First off what a great site...so much info...I am wet behind the ears with so much knowledge to take in. Try to make this easy for you and myself. I am starting out and was hoping with a goal of using my solar to be plugged in with an inverter(pure sine wave) to the house to compliment my energy usage...assuming that is a no no due to microfit program, so unsure. Understood these are stackable as well. Just thinking of all options..

[Rob Beckers]

Hi Georgie,

Welcome to Green Power Talk!
What do you currently have in solar PV? Just plugging inverters into the grid is very much frowned upon by the utility companies. Battery based inverters won't work (you'll fry them the moment they connect to the grid, unless you have one that has a "sell back" option). Grid-tie inverter would work, but there are rules in place so line-men don't get electrocuted because your inverter is powering the lines when they think it's switched off.

-RoB-

[Georgie Porgie]

Thanks for reply...first off I am just building 2x 36 watt panels from scratch and then will do the battery bank situation...im in no hurry...was wondering more on the later on, then now...first ill power outside deck lights...then garage..and keep building...I know of the pure sine inverters with the shut off features for black outs that allow you to plug directly to outlet...was sure it was a no no...but hey its a forum...and you never know what you read on the net. Really these inverters are stackable but you would not get rebates just be helping your own electricity....unless you were on the large scale then of course micro fit.

[Dave Turpin]

You are talking about the inverters you can buy on eBay or the like.
Do they work? Yes. They don't have MPPT so they are less efficient, but they do work.
Are they safe? Most have anti-islanding features.
But... Are they legal? Not in the US and Canada, not in the EU, and I don't know about elsewhere. At the same time, if you are producing only 70 Watt, it's not like the power company will notice. Your homeowner's insurance will probably deny you, though, if the inverter burns your house down.

[Joe Blake]

George,

I started out by building my own "stand alone" system with 128 watts of PV panel, a regulator, 240 volt inverters (3 of, 150 watts, 300 watts, 600 watts) and deep cycle batteries. (Now up to about 150 Amp Hour at 12 volts). I use a couple of automotive battery chargers to augment the 128 watts of solar power. However, the chargers are running off my roof top PV array, which is feeding back into the grid and giving me a small amount of credit. (Up to $112 Australian as at my last bill.) This way the batteries are always at maximum charge, and the battery system is completely independent of the roof top system (other than the charger(s)), and when, as happened last Monday, we have a fairly violent storm come through and take out the power to about 50,000 houses, I'm still able to run a couple of camping freezers and my TV. Because of the isolating function of my roof top inverter, I lost my mains power, but it was no big deal, especially since I've got a 12 volt generator attached to my indoor bicycle trainer. :D According to the power meter I can peak at better than 130 watts, but I can comfortably maintain 70-80 watts for lengthy periods.

I think I've got the best of both worlds now. :blink1:

Joe