How much does a photovoltaic storage deliver?

Hello,

my question is about a power storage system.
Assuming it has a capacity of 6 kWh.
Then I could (theoretically) operate a 2000 watt fan heater for three hours. Or three fan heaters for one hour.
But: does the storage system even deliver that much "power"?
I was discussing this with an acquaintance yesterday, it was about a "Fasssauna" in the garden.
Can it be operated (4kW) with a power storage system (for free) (as long as the battery is fully charged) or does the storage only deliver part of the required power and the rest comes from the grid?
I hope you understand what I mean with my question.

Thanks, Tom

The maximum discharge power is specified by the manufacturer in its datasheet.

Thank you, I was looking for that expression. So it is basically sensible to do the laundry and run the dishwasher in sunshine even when the storage is full, as long as the photovoltaic system is generating the necessary electricity. Okay...

When charging and discharging, there are always conversion losses.

Prio 1: Use electricity directly "from the roof"
Prio 2: From the storage
Prio 3: From the grid

Hello, attached is my energy balance from what has so far been a really bad August. Our storage has 13.8 KW, our garden sauna has a 9 KW stove. It is clearly visible that the storage cannot deliver everything and of course is emptied very quickly if you assume an average operating time of the sauna stove of around 3 hours.

Green: Photovoltaic production. Blue: self-consumption from the roof or storage. Red: grid usage

But: does the battery even deliver that much "current"?

Most batteries/cells/energy storage systems are based on LiFePo chemistry and can normally be discharged at 1C without any problems.
1C means discharging the battery in one hour. With 6kWh of energy, that would be a constant output of 6kW.

The problem, however, lies with the inverters. Many have a current limit that kicks in beforehand.
But high power outputs are indeed possible with HV (high voltage) batteries.

For that, you should look at the datasheet as already mentioned.

Our battery has 13.8 KW, our garden sauna a 9 KW stove.

If the battery has a power rating of 13.8kW, you can of course easily supply a 9kW load with it.

However, you probably mean 13.8kWh instead of 13.8kW, and thus the answer has nothing to do with the question.
Especially since your graphic doesn’t even have a label.