When we evaluate these different technologies we are discussing them in the context of immediate solutions. Rather than waiting for a panacea which may or may not ever happen, we are basically advocating for a flexible, multi-fuel approach that considers the best and worst of each available fuel source.
Vegetable Oil-
Vegetable Oil is product that comes from crops like soy, cottonseed, canola, and many others. Vegetable oil is run in modified diesel vehicles by using a series of heaters or heat exchangers from hot engine coolantto bring the vegetable oil to a thinner viscosity than it is as at room temperatures to allow it to behave closer to diesel fuels. It typically has excellent emissions because it does not have the contaminents of diesel. The politics of vegetable oil can be debated but typically vegetable oil does not compete with food crops because it does not destroy the meal from the crop unlike corn-based ethanol. The greenhouse gas reduction of using vegetable oil as a fuel could be in excess of 90% reduction versus petroleum fuels. However, there is not enough vegetable oil to power America’s fuel demands and this also introduces many other potential negative aspects.
Biodiesel-
Biodiesel is commonly confused with vegetable oil because it is usually produced from vegetable oil. Biodiesel, which can be run in any diesel engine, produces staggering emissions reductions versus petroleum diesel fuel because it does not contain the contaminants, carcinogens, particulate matter, and sulfurs of diesel fuel. The principle problem with diesels is their fuel, not the engine design. Biodiesel is also considered an 78% reduction in greenhouse gas versus diesel fuel. Biodiesel, however suffers from some issues with vehicle compatibility and gelling because of its formulation. Until biodiesel is re-formulated it must be reconsidered as a fuel so it performs better and so that the lingering issues with potential conflicts with food-crops can be cured.
Natural Gas-
Natural gas is primarily methane gas that occurs naturally in the ground. Unburned or in an environment where it is uncaptured allows methane, which is 21 times more-potent a greenhouse gas than CO2, to escape in the environment. However, natural gas, when burned in buses and fleet vehicles, can offer an immediate 70% reduction in greenhouse gas versus versus diesel fuel. Vehicles which burn natural gas can also burn “biogas” which is methane gas captured from land fills, methane digesters, and other waste locations (literally “running your vehicle on garbage”) but transition to a natural gas infrastructure is needed first. The largest single issue with natural gas is the big business (Haliburton Corporation, etc) trend towards natural gas drilling called “fracking” which basically hydraulically inserts “fracking fluid” (composed of many dangerous chemicals) and millions upon millions of gallons – per well) to basically cause mini underground earth quakes which in-turn release stored natural gas. Natural gas must be refined before it can be burned and this unrefined natural gas is dangerous across the board to water wells, local residents, and the environment as whole and must be made illegal, immediately.
Synthetic Diesel-
Synthetic diesel is a very interesting trend that is similar to biodiesel except that it is synthetically manufactured from one of many sources. Diesel made from other fossil fuel sources such as coal seems like a mistake, but synthetic sources from non-fossil fuel sources could provide some promising opportunities.
Electric-
Electricity in America still comes from over 50% fossil fuel sources like coal-fired power plants. That said it is tremendously efficient to use and could be an excellent option. The largest limiting factor is limited range and/or extreme weight due to the volume of battery storage required for any overland vehicle.
Hybrid – Gasoline/Electric-
Interesting concept but it still uses dirty gasoline fuels and their emissions. Gasoline Electric is an excellent stepping stone.
Hybrid – Diesel/Electric-
This is the same as gasoline electric but is rarely available other than some expensive commercial vehicles such as fleet buses. It could potentially have greater efficiency because diesel engines are typcially more efficient than gasoline.
