no doubt the eroi of wind can get well into the double digits but only if you build it on a suitably large scale. Solar does not have the same exponential scalability. 2 solar panels are only twice as good as one. a 4m rotor yields 4 times the energy of a 2m windmill.
While I admit I'm speculating a bit, I'm sure it's not nearly as simple as that. With wind, you have to scale various components along with the rotor -- particularly the rotor shaft, gear box and brake mechanism. That adds to the cost whereas with solar you just have to add more of the same identical components. More to the point, the spacing between rows of wind turbines is about 15 times the rotor diameter, so when you double the rotor size you also double both the width and the spacing, and thus quadruple the land area needed. So even though wind energy scales with the square of the rotor diameter, it only scales linearly with land area usage, which is the same as for solar.
There are 3 parameters to consider when judging the quality of an energy source:
concentration or energy density
availability (on demand, or storage component)
Fossil fuels have all 3, nothing else does. Uranium and water power are not abundant, solar and wind have limited availability, not are they concentrated.
The energy density is most important for transport, where the vehicle has to carry its own enery supply (unless connected to the grid which is practical only for rail transport). It is also important for fuels that will be used to produce electricity on a utility scale, since you have the cost of transport to the generating plant. It's not nearly so important where electricity can be produced (and perhaps used) in place, i.e. with wind and solar. And while solar is diffuse energy, it's not exactly weak at 1.3 kW over every square metre of the earth's disc.
But in any case, there is no point complaining about the lower concentration or intermittent availability of renewables -- that's what we are going to have to live with so we will need to start thinking a different way. A completely different paradigm is that we start adjusting demand to availability rather than the other way around. Up to a point, that's easier than you think -- with the right technology and enforcement, much domestic demand could be deferred to periods when electricity is most available, and adjustment of industrial usage is very possible ... for one example there is an ongoing experiment with European cold storage facilities, where giant refrigeration equipment can be allowed to vary the temperature within certain parameters without effect on stored food, but allowing them to adjust their electricity requirements to availability.
Biomass contains the storage component thus allows high availability, is relatively concentrated, is abundant in certain areas, but not everywhere, so it may be the closest competitor.
I'm a renewables fan, but I'm not at all convinced about biomass. Apart from a very few products like palm oil and sugar cane (both of which only grow in the tropics), the energy density is rather low. Corn ethanol is a scam from an EROEI POV, wood for electricity generation is only marginally useful and then only if the generating plant is closely collocated with where the wood is being harvested. The only thing biomass has going for it is the capability of being turned into bio-alcohol or bio-diesel, to help with the problem of liquid fuels for transport. But once you accept that you must do some of that to solve the transport problem in the short term, both the sustainability and EROEI arguments go away (at least for a while). And we have better ways of doing it without biomass, the example I pointed out before being methane to methanol which is already done cheaply and commercially.
Solar and wind are usually be used via a grid, so this must be accounted for in EROI accounting. If you are off grid you need batteries, which certainly condemn them to less than parity, since batteries are so high in embedded energy. If plugging into the grid the parasitic load of an inverter must be taken into account. Many EROI calcs do not account for all the energy costs as far as I am aware.
You are not comparing like with like there. If fossil fuels were to be used on a household scale, you'd need the cost of gas or steam turbines and cooling towers for every house. Clearly there are economies of scale to be achieved at the large utility level, which is why we do things that way today. The economics may work out differently for renewables -- perhaps at the municipal level for solar. Again, there is no point comparing the way we do things we do today with how they will have to be done in the future, as if our present level of convenience was utterly sacrosanct.
In theory, but not yet in practice. Separately we must account for using one reactor bred off another's fuel over a long time and take that into avcount
Not sure if you were applying that to fusion energy? There are some versions of fusion that would need tritium bred from lithium by a previous generation of reactors, but tritium is radioactive and preferably avoided if possible. But if necessary, so be it. Tritium can be bred while still generating energy, so there is an issue of complexity, but no additional EROEI issues.
You reminded me of something else though ... fission power still has a lot of mileage in it. For a start, there's lots of material from decommissioned bombs lying around. But the proliferation issues are problematic. But there is also the thorium fuel cycle where 232-Th is used to breed 233-U -- this uses an abundantly available natural isotope of Thorium to breed fissile Uranium. Apparently the proliferation problems are much less, and Thorium is allegedly lying around in copious quantities on Indian beaches. The world may get over its aversion to nuclear fission when the lights start going out, so we have many different options here.