ᐅ Ground source heat pump and domestic hot water heat pump???

Hello dear community,

I am currently considering the issue of domestic hot water heating.
Photovoltaics and a ground source heat pump are almost certainly going to be installed. Now I am wondering what the most efficient way to heat domestic hot water is: using the ground source heat pump or an additional hot water heat pump?
How efficient is a ground source heat pump at heating domestic hot water during the summer? After all, the ground temperature is cooler than the ambient air temperature.
Hot water heat pumps have the additional benefit in summer of cooling the air, and there are apparently models available that are combined with ventilation systems.
In that case, the ground source heat pump could be turned off completely in summer, which might extend its lifespan. But of course, this would also mean adding more equipment that could potentially fail.
I tend to prefer as little technology as necessary. Are there any recommended combined systems that provide heating, ventilation, and hot water production all in one? I know that’s asking for three features at once...

I would be very grateful for any suggestions and experiences.

Best regards,
Judyyy