The main reason why this process isn't "something for nothing" is that it takes twice as much electrical energy to produce energy in the form of gasoline. As Aircela told The Autopian:

Aircela is targeting >50% end to end power efficiency. Since there is about 37kWh of energy in a gallon of gasoline we will require about 75kWh to make it. When we power our machines with standalone, off-grid, photovoltaic panels this will correspond to less than $1.50/gallon in energy cost.

Doesn't it sort of defeat the purpose of gasoline being used because it's so energy dense? Like, this seems to suggest little more than the benefits of electrification in transport.