energy loss and its utilization

[sairam]

how to do simulation for hybrid ( Grid tied and off grid both Combined ) system ?

i was designing solar off grid system where there is huge energy loss when battery is in fully charged condition.

how to use this energy ? is there any system available by which we can feed this energy in to grid ?

Thanks

[André Mermoud]

If you have a "normal" grid at disposal, a stand-alone system is usually not very useful (not economically optimal).

Now except grid, there are no much uses of the excess electricity (you could heat up water for example).

Please see my comment about hybrid systems in the FAQ : Can I include a battery in a grid-connected system ?

[sairam]

thanks for your reply,

but here situation is different,

we have to provide off grid power to lighting and fans for hospital with 24 hours battery back up.

is there any way to use excess power when grid and solar is available and battery is fuly charged ?

battery will be used during power failure only.

total isolated off grid AC connected load is 73 kw and other premises grid load is 325 kw.

[André Mermoud]

As explained in the FAQ referenced above, you have many different strategies when mixing solar system, batteries and grid.

In your case the batteries may be charged either by the solar array or by the grid. Which will be the conditions and strategy for chooosing one or the other source ?

The batteries will probably feed only emergency circuits in your system, involving a double-circuit in your building. How to define these needs ?

When the batterie are full the solar array will inject its energy into the grid - through which kind of inverter ? (probably a standard grid-connected),

In case of a weak grid, how to model the grid unavailability ?

etc...

Such an installation and operational conditions are too complex for being defined in a general software like PVsyst in the present time.