I used to work for a solar energy firm as chief engineer, and had to make efficiency and cost comparisons with wind power.
Globally and nationally there is no question but that we need both, and indeed all non-CO2 generation technologies. It's not either/or.
Comments on wind speed and urban effects are right. Indeed, not only does wind power increase with the cube of the wind speed, the wind speed itself increases approximately as the cube of the height above the ground. So there is a huge advantage to making them really big and siting them in "open" areas. The domestic ones may be convenient for certain purposes but are not very serious as generators overall. More for show. Also they have more liabilities, in that a turbine blade is more likely to come adrift and do some damage than is a solar panel.
Solar energy is more costly in the UK climate at the point of generation, but significant in that it downscales better. A domestic installation is fine for efficiency; there is some economy of scale with the investors but not huge. (I do have them on my roof). However, a big point is that the network delivery is already there in the National Grid. In a remote site (offshore, or far from a centre of population) the cost of the copper and installation of the power cables can be comparable to that of the generator itself. Also, one can predict average solar irradiation anywhere in the world from NASA data, to a precision of about 1 km. I used to use it for prediction of potential national markets. Solar does make a significant contribution to a carbon-free economy even in the UK. One can do the same for wind power in open areas but not in urban areas as people have already stated.
Terry - yes you are right, though the cabling is very location-dependent. An enormous storage resource which will become more important is electric vehicles, which in general do not need all of their non-driving time to recharge. In the meantime they can store energy and feed it back to the grid at peak hours. The BEV base is already about equivalent to a big power station in the UK, though just starting to be used in that way.
The energy used in manufacture is also relevant. Big wind turbines are quite efficient and pay back the energy used to build them in around a year. Silicon solar panels take longer, probably about three years now (it was five years when I was doing these sums about ten years ago but has improved. Concentrated PV using advanced compound semiconductor cells and lens/mirror concentrators is actually more efficient in regions of strong sunlight, using less land area and only needing a year to payback manufacture. This is the area I was involved in. But all the companies engaged in CPV failed when the Chinese drastically cut the price of silicon solar cells and got virtually the whole PV market other than space applications, on cost of installation. (I am not making a political point here; I have no idea of their internal economics and cost of production).
