Currently in Colombia, it's been developed a massive public transportation systems in several major cities based on bus-type vehicles that use fuel and gas engines. This fact is not currently considering the electrical traction as it is made at the "Metro de Medellin" - the unique metro railway in Colombia-that uses an electrical distribution system along the railway with the advantage of Colombia's sustainable hydraulic energy. In its place the systems are being designed using gas and fuel without considering the uncertainly in the exploitation capability, the duration of these natural resources and the amount of CO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> Ton delivered to the air. The paper exposes several aspects of making an energy planning with electrical distribution network to use on a new Medellin public massive transportation instead of the use of gas and fuel. It will be considered the completely gas and fuel engines vehicles substitution by electric engines vehicles keeping in mind the new energy planning distribution system along the bus-ways, the possibility to evaluate the project as a Clean Development Mechanism (CDM) with the quantity of CO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> not emitted and energy costs ($/kWh, $/m3 of gas, $/gal of fuel and $/gal of biodiesel). It will be certainly a great opportunity for the electric energy distribution company because of the increase of the electric energy demand. This assessment might be applied in several other cities in Latin America, with similar features that Medellin.