The May 2007 edition of Popular Science has an article titled Green-Fuel Guide where they give a description of gasoline alternative vehicles that they predict will be in use by 2027. They also give an estimated market share of these technologies and their pros and cons. I found it interesting and thought I would post it for those of you who follow such stuff.
Batteries: Pros - Clean Energy, High MPG Cons - Not powerful enough Est. Market Share - 30% Whether in hybrid form or alone, electric propulsion will lead the way out of the petroleum era.
Natural Gas: Pros - Clean, Abundant, Domestic Cons - Few pumps, Nonrenewable Est. Market Share - 3% This cleanest burning fossil fuel heats half of the homes in the United States. Why not siphon a bit off for your car?
Ethanol: Pros - Renewable, Domestic Cons - Energy-intensive Est. Market Share - 6% Corn-based ethanol won't meet our energy needs, but cellulosic ethanol could reverse its fortunes.
Diesel: Pros - Great Mileage, Available now Cons - Still made from oil Est. Market Share - 20% Its low sulfur content and sophisticated exhaust cleaners set the stage for a big diesel comeback.
Biodiesel: Pros - Clean, High Energy Cons - Limited Supply and Market Est. Market Share - 4% Already common in Europe, biodiesel could get traction here as well but it needs for regular diesel to catch on first.
Hydrogen: Pros - Zero Emissions Cons - Enormous Investment Needed Est. Market Share - 2% Hydrogen remains the gold standard for eco-friendliness, but its prospects are dimming as reality sets in.