New law in BW regarding heating system

Hello everyone.

Is it true that I have to install a solar system on the roof if I want to replace our oil heating system?
If the new heating system costs 8,000 €, how much do I then have to invest in [Photovoltaik]???
Thanks for your help.

What now? Solar or photovoltaic? - And no, I am not aware of such a law.

However, I do not want to deny that solar support can make sense. Especially in summer for hot water, it’s nice not to have to burn oil or gas.