Basic inverter question

[yanosj]

We are about to start building a house in the Virgin Islands. Power is about $.50 a KwH. Looks like no chance of net metering. The choices will grid back up or off grid.

We have plenty of sun and very good wind (trade winds). My question is about inverters. Do inverters only charge the batteries or can they send the power out directly as AC to house? I think that might matter because if the power goes out without going to the batteries it would make sense to have both solar and wind so the wind could supply the lower level at night and stop the batteries from cycling as often. Otherwise it would seem to make more sense to just stick with enough solar to meet our needs as it seems much cheaper than wind and wouldn't make a difference to the batteries.

Thanks

[Sunking]

You need to tap the breaks and need more information.

50-cents per Kwh is high. Go off grid and battery cost alone are going to be $1 per Kwh or more on your island. That does not include any equipment cost. Additionally you will be very limited in how much power you can use in a day. It also means needing a generator to run on those cloudy days. That means fuel and equipment cost on top of battery cost.

Sure 50-cents per Kwh is high, but still a lot less expensive than solar. With utility no daily limits on power and even power on cloudy days.

So be careful what you ask for.

[inetdog]

There are hybrid inverters which can operate in a grid tied mode with specific provisions to prohibit feeding power back into the grid. You have to have a battery, but you do not have to depend on it to supply power while the grid is up, even though when there is no PV available.
With such a system (significantly higher cost for the inverter) you could get by with a smaller battery bank and possibly reduce the cost of your power from solar sources well below .50/kWh.
But such as system would have to be carefully designed and configured. A newcomer would be well advised to read all that he can about this mode and also try to find a local source of knowledge.

The other alternative would be a purely grid tied inverter with the ability to limit PV generation to prevent feeding into the grid.
I do not know of any US marked inverters that operate that way, but there appear to be products designed for the British and other worldwide markets with this configuration option.