It produces about 3/4th of the power I consume. On rainy days it's about 1/3rd of the power. So I could get by without a generator if needed. And with a decent generator I could be off grid completely (though the gas/diesel to run it would cost more than the kWh I pay the power co).
It'll take anywhere from 11 to 13 years to pay for itself (depending on the inflation rate of per kWh charge), assuming the Dims to put a punitive tax on power to save us from our carbon sins. If they do that my system will pay for itself a lot sooner.