It makes 1725 watts or 1.7KWH period with all 8 panels combined. Just look at the link LT1RX7 posted.
The fed will give you a tax credit of 15% of the cost of the system, the State you are in may also give you a tax credit. The state I live in gives another 15% credit, so basically the gubbermint will pay for 30% of my solar investment.
1725 watts is not bad for $10,000 especially when you consider 30% of it will be a tax write off, so figure 7K. Avg power cost is 12 cents per KWH so lets say its producing peak power for 10 hours a day so 1.725 x $.12 x 10 = $2.07 every day so it produces about $60 worth of power each month of sunshine. Lets just say its going to take about 10 years for it to pay for itself. Solar panels last at least 20 years so its not a bad investment, too bad the cost hasn't come down more.
Of course under the Cap and Trade system it would only take 3 or 4 years to pay for itself as your electricity rates would likely triple very quickly under that bill.