Regardless the batteries have to be properly maintained....

http://www.batteryequaliser.com/products/product_battery_maintenance.htm

Yes, assuming that you have a proper controller and your utility allows you to put power into the grid. It is one of the design principles behind the Smart-Grid.

Batteries might save some voltaic-generated power, but the cost of saving it with batteries will likely exceed the money spent. The grid acts as your battery only if the voltage generated is more than the voltage on the grid.

The grid acts as your battery ONLY if it is exactly the same voltage and frequency as the public grid it is monitoring. A grid tied inverter will not operate otherwise. (UL 1701 rule) Using this terminology is misleading, however, because the act of repulsing your PV production onto the grid (by failing to consume it) is what actually builds the credit that you will utilize when the opposite condition occurs,(when your demand exceeds your PV production) Hence,the comparison to a battery. Technically, they are very different.

A grid tied PV system is actually much more efficient than using a chemical battery, but fundamentally different, primarily because a battery will supply power for your use when the grid is down, and a grid tied system with out storage is not useful when the grid is down. A battery is not particularly robust or effective at returning the watts you need to charge it.

Finally, using batteries is very expensive, and contributes no financial feasibility to all but the most remote, unpowered locales.

Yes this will work fine without a battery. There are many grid tie inverters out there to do this.

But remember that when the grid power fails your grid tie inverter will also shut down and if you want to be able to use your system when the grid is down you will have to build a mini grid system with a battery back up. With such a system you can switch over the big system using the mini.grid to sort of fool the grid tie inverters into thinking the grid has returned. This way you can still use your system when the grid is down. We have to do this here in the Dominican Republic because we get black outs daily.

The reason grid tie inverters go down with the grid is basically safety. If linemen are working on the grid they dont want people feeding power into it from a variety of different places.

John

thanks all.... your opinions about this will much helping for me...

thanks n regards

Yes, grid tie inverters are very common, and for many people provide a better return on investment than using battery storage.