Ill-formed question. You must put solar in context: latitude, insolation.
Here in northern New Mexico, at 6000', my 7kW PV array(s) work extremely efficiently in winter, arguably slightly more efficiently than in summer because the panels prefer it cold. They collect somewhat less energy than in summer due to shorter days, but that's not a question of efficiency.
Yeah makes sense, I was thinking mainly about Europe and somehow forgot that the climate is considerably colder in the US but there is still much more sunlight during the winter.
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.
Also it seems that with no subsidies etc. overall heat pumps are considerably more expensive than gas