The merits of installing PV panels are the same whether you have a heat pump or not to be honest. The point _OkGo_ is making is that PV will not be generating electricity at the times your heat pump needs electricity, so putting up PV thinking it will provide free electricity to run your heatpump does not make sense.Just on this about the PV solar again, I'm hopefully soon going to be moving to a new build (A2 or A3 BER) that'll have an air to water heat pump, underfloor heating downstairs and radiators upstairs. I'll be working from home most of the time and will probably go for an electric car the next time I change cars. The house won't come with any solar panels as standard, though I was considering asking the builder to install PV. From what you've said it sounds like it may not be worth it, is there any merit to installing PV in this case?
So you just need to look at your electricity usage and ignore whether there is a heatpump there or not and see if PV makes sense. The conclusion you'll likely come to is that it has a payback of somewhere between 6-10 years depending on whether you go for a battery or not and assuming you get a good price. If you plan to stay in the new house for 10/15/20 years then that payback period is fine and you'll be saving a decent few quid on electricity bills.