The current annual world garlic production is about 28 million tons per year. There is about 6% mass percent of garlic roots per mass unit of garlic. At a garlic root to activated carbon conversion rate of 20 %, a maximum amount of 0.34 million tons of garlic root-derived activated carbon could be made per year. Based on the SSA sorption capacity of 0.20 mol/kg and 1h cycle times, this amount could capture ~26 million tons (Mt) CO2 per year. Assuming a cycle life of 100,000 cycles, the sorbent would live 11.42 years, hence on an annualized basis 299 Mt CO2/year could be captured, i.e. SSA with garlic-root derived carbons could be scaled up to this amount (see section S9 for calculations). Assuming a typical activated carbon production cost of $3.00 per kg, a cost of $10.00/kg for the PTFE binder, $6.00/kg for the carbon black, and $1.35/kg for the gluten, the cost of an electrode is $3.38/kg at a AC:PTFE:CB:Gluten ratio of 80:5:5:10. At an electrode thickness of 0.7 mm, and electrode density of 0.20 g/cm , this translates to an electrode cost of $0.47/m 2 . Application of a Lang factor of 3.63 gives $1.71/m 2 (section S11). The productivity at 0.20 mol/kg and 1h cycle times is 0.028 mol.h -1 m 2 or 0.0108 tons.m -2 year -1 . Assuming an interest rate of 3% and 11.42-years electrode lifetime gives a capital recovery factor of 0.10. This results in an annualized electrode cost of $0.18/m 2 and carbon capture cost of $16.82/ton CO2. This does not yet consider the counterelectrode, the separator, and the electrolyte. The symmetric counter-electrode does not further increase adsorption; hence it doubles the cost to $34.64/ton. The cost of electrolyte is negligible, but the separator increases the cost to $75.91/ton CO2 assuming a separator cost of $1.2/m 2 . A further consideration is the expanded graphite current collectors ($5/m 2 ), and the carbon cloth as the gas diffusion layer ($9/m 2 ). Figure (a) shows the cost breakdown of these components. The number and thus cost of current collectors can be minimized by scaling the technique using bipolar electrodes in series similar to fuel cell stacks because then only two current collectors at the end of the stacks are needed. If, for instance, there was a stack of hundred 1m 2 electrodes, one would only need two 1m 2 current collectors, and hence they would not significantly add to the cost (to $79/ton in this example case). The ionic current within a bipolar electrode must be interrupted to avoid the shortcircuiting of the ionic circuit. This could be accomplished by "gluing" the positive and the negative electrode together using graphite cement to give the bipolar electrode, or by using carbon black containing polyethylene foils. The graphite cement would clog the pores at the interface of the two electrodes interrupting the ionic circuit. At an estimated graphite cement cost of ~$1/m 2 the carbon capture cost would increase to $115/ton (section S13 to S17). The carbon cloth as the gas diffusion layer is the most expensive component ($9/m 2 ), would increase cost greatly to $432/ton. We are currently exploring cell designs without carbon cloth that use electrodes with imprinted gas flow channels. This possibility arises from the large thickness of our electrodes (~0.7 mm).