Counting efficiency in CO2 management

For me it comes down to relative efficiency, compare the optimum battery to the optimum fuel driven generator. We get a relative comparison.

Solar is a great reference point, the energy collect long the equator in one square meter, and the most efficient solar electric conversion.  That standard gives you the real, land space cost for renewables, used at the location.

Great standard, and relative to that we can compute the efficiency of various  CO2 extraction process, done at the spot, measured in renewable land space.  We are removing all the liffe cycle depreciation and pipeline or power line or lithium or fuel tanks, or any of that.  Just looking a efficiency of pilot plant energy conversion projects. mostly research engineering at a net negative energy cost relative to current practices.

I can, and soon will, guestimate the energy efficiency of a simple atmospheric CO2 extraction . Solar electric to heat pump extraction and filtering of CO2. Or the relative cost in Land space, for solar electric electrolysis of water. Make a game of it, constructing green energy with surplus solar electric.

More complex, solar driven bioreactors,for both alcohol and diesel.  In the game, they all have to be local and judged by land space solar equivalent loss. Ignoring life cycle costs.

Now solar electric, alone, wins in local conversion efficiency, by definition we say. It is about 20%, local at the spot. Under ideal, and sanitary bioreactor, biofuel equivalents might be 5%, one fourth of solar.  That is, 5% of a square meter of already converted solar electric, in one form, or a directed sunlight with special algae might skip the solar electric conversion. Put processes together and make plastic from the atmosphere, at great cost in land space.  Even a bushel of corn used in a fermentation pilot can be costed in terms of equivalent land space. Build a huge data base, begin searching everywhere for solutions to the obvious inefficiency steps.  We have net energy flow to work with.