Approx calculation on hydrocarbon synthesis for evaluation .
This method has the object of using renewable energy to eliminate CO and CO2 pollution from
power plants or any big polluter in order to produce gasoline free of heavy metal, sulfur and
nitrogen oxides.
Based on:
        6 CO + 9 H2 ==> C6H6 + 6 H2O
  
Fisher & Tropsch  exothermic reaction about -400 KJ /reaction at 220 degrees Celsius on fe
catalyst and about 10 bars.

   2 C +  O2 = 2 CO - 220 KJ  or        C + CO2 = 2 CO  
1 mole of C6H6 =  78 grs = 12.2 moles /liter of gasoline.
1 mole of H2     =   2 grs  = 500 moles /kg
1 mole of CO    =  28 grs
1 KWh electric  = 0.005 US$.
50 KWh to produce 1 kg of H2 via electrolysis = 0.25 US$ /kg of  H2 = 0.0005 US$/mole

Th price for a liter of C6H6 =  (0.0005 US$  x 9 moles of H2  + 0.00 USD x 6 moles of CO ) x 12.2
moles/liter  = 0.055 US$/liter.

The enthalpy delta of the chemical reaction being positive, the energy collected could cover the
cost of the investment for the reactor.

Remarks:
In this calculation, we use only C6H6 molecule to make it easy to understand.
Gasoline being a mix of molecules from C5 to C15.
CO and CO2 are collected at the exhaust pipe of a power plant burning either CH4 or coal but
using pure oxygen produced by the electrolysis of H2O.

In this configuration, the power plant becoming pollution free will pay for the service.
By using that method, the power plant can burn more coal therefore reducing the cost for kWh
produced.

Based on today's gasoline price of around US$.8/l pretax.