[wildekek]

There is a lot of 'it depends' on the efficiency of solar in winter. Solar is actually more efficient in winter, but depending on your latitude you get less hours of sun, and a lower angle of incidence.

Heat pump up-front cost are higher indeed. But depending on your local grid situation, they can drastically decrease the amount of electricity you shove and pull from the grid, by adapting to your solar performance. You can use them to convert your house into a thermal battery. Managing the time when you consume and produce energy will become the most important cost factor in the next few years in countries that advance towards renewable energy sources.