KFW funding for energy storage/photovoltaics

Hello everyone,
yesterday I listened to an interesting lecture that included a few example calculations regarding the profitability and economic efficiency of energy storage systems.
The topic of photovoltaics is currently becoming more profitable purely due to the increase in own consumption.
What is your opinion on the subject? Various calculation examples showed that the stored kWh averages below 23 cents.
The consideration included maintenance costs, repair costs, etc., and an operational period of 20-25 years for the system was assumed.

Regarding my question about the Kfw program, it is as follows: The program is only valid this year. Does that mean that the installation of the system must take place this year, or must the order for the system be placed this year? I am currently building, but the construction will not be ready for occupancy until June/July. Installation would probably not be possible before March/April...

I assume (pure estimation, please do not interpret as a final statement) that, as with most Kfw programs, the application date is decisive. You also apply for KFW in other funding programs for house construction and are not yet finished with the house and still receive money ;)

I suspect quite naively that the program will be extended / relaunched - why should the topic of energy storage already be 'done'? The spread is abysmal, there is still a lot to do...