ᐅ Solar for hot water and heating, or is photovoltaic better for electricity?

Hello.
Our house will be heated with gas. To just meet the energy-saving regulations, we now need to decide soon whether to install a solar thermal system on the roof for hot water and heating support, or if it would be better to install a photovoltaic system to generate electricity.

What is your opinion on this?

Solar hot water. Everything else is just wasting money. The costs you spend on photovoltaics won’t pay off within a typical timeframe.

How large should the photovoltaic system be, and what is the orientation of the roof?

Nordlys schrieb:
Solar hot water. Everything else is a waste of money. The costs you put into photovoltaics won't pay off within a normal time frame.

Exactly the opposite.

Photovoltaics will not work. The renewable share must contribute to heating, meaning with photovoltaics you would have to use an electric heating element to feed the generated electricity into the heating system. This is completely uneconomical.
Your option is solar thermal.

Mycraft schrieb:
How large will the photovoltaic system be, and what is the orientation of the roof?

Flat roof with an unobstructed view (no trees or similar) facing south and west

Path of least resistance: Alibi solar, meaning 5 sqm (54 sq ft) of solar thermal with a storage tank in the utility room.

Otherwise, large photovoltaic systems, but as Alex already mentioned, the renewable share might still be too low. Then there are various other obscure scenarios.

With more insulation plus controlled mechanical ventilation with heat recovery, it might also be possible. Everything needs to be calculated.