The fast growing depletion of fossil fuels resources calls for a switch of our economy to alternative energy sources. A very challenging problem concerns finding a reliable, sustainable energy source to be used as a transportation fuel for private cars. For the long-term future, the main source that will be available to us is electricity from alternative energy, therefore cars will have to rely on it. The aim of this presentation is to discuss and compare in terms of efficiency, costs and safety issues the four options that we presently have or can envisage, which all contemplate either a direct or an indirect use of electricity generated from alternative energy sources. We will also show that while the first two options are available, proven technologies ready for implementation, the other two options are research programs the success of which strongly depends on the achievement of breakthrough results. The 1st option is the plug-in hybrid car. An hybrid car runs on a battery for 40-50 miles (sufficient to cover about 80% of our daily commutes) and automatically switches to a conventional gasoline engine when the battery is low, which also recharges the battery. The gasoline, especially for the future, can be produced in a sustainable way from syn-gas processes, where the CO is obtained from partial gasification of biomass while H2 is generated by electrolysis using alternative energy sources. We will show that converting the H2 to gasoline and diesel is the best method to store and use it, and it also allows the highest yield of fuels as compared to other biomass conversion processes. Although it cannot compete in cost and efficiency with direct use of electricity, at present plug-in hybrid is the best compromise, as we do not have batteries that allow driving cars solely on electricity. Therefore, for the many advantages offered, plug-in hybrid cars are unquestionably the preferable option for both the near and the long term future. The 2nd option is to use the same cars as we use today, but the gasoline will be produced as in the previous case. This option not only can be immediately implemented, but for the short-range future it can help reduce the consumption of petroleum. However, for the long-range future, there are serious concerns about the sustainability of this option, as we might not have sufficient biomass resources to provide all the gasoline needed. Also, we will show that this option is by a large factor more expensive than the previous one. The 3rd technology discussed is the all-electric car. We will show that this type of cars is not ready for implementation, and a breakthrough in research is needed in order to be able to build a light battery that can power a car for several hundreds miles, and that can be quickly recharged. However, this technology can be a complement to the first option. In fact, any time a new and better battery is produced, even if its drivability range is too limited for an all-electric car, it could be perfectly suited for a plug-in hybrid car. Finally, the H2 car will be analyzed, which shares with the first two options the production of H2 via water hydrolysis using alternative electricity. But, similarly to the all-electric car, also the H2 car needs some breakthrough results before it can be implemented. We will show how the direct use of H2 also introduces severe safety and costs issues for both the cars and the new needed distribution systems. Therefore, given the present availability of the first two options, it should be reevaluated if the development of a H2 car still makes sense, and a preliminary analysis will be presented.