What are the alternative car fuels recommended by todays science world? What is the most effecient method?

Question

I'm aware of Hydrogen 7 technology, pioneered by BMW. However, I heard that hydrogen as an alternative fuel is one of the most in-efficient. I'm also aware of working electric engines that go back as far as Tesla's designs, and Tesla Motors whose recenlty created a fully electric 220 hp beast. The Tesla Roadster. I want to get into the "meat" of the science behind alternative fuels and since the technology apparently is public knowledge why aren't we as a society mass producing these marvels. What is the government hiding? Besides it's oil addiction. We as a species know our immediate threat to extinction can be erradicated if we take immediate action. So what's the problem? I recommend renting "An Inconvenient Truth" for all those that haven't seen it. Please back up opinions or theory by citing reliable references before entering it into this blog. We want to keep this blog as reliable as possible.

Answer 1

Before answering your question, two things:

First, Y! Answers is not a blog.  It is a question-answers site, where people can ask questions, and then hope that someone knowledgeable responds.

Second, the government is hiding nothing.  Oil has simply been so cheap that alternatives really haven't been (re)investigated.  Also, we seem to be hitting a sort of catch-22.  Everyone wants knowledgeable scientists to investigate these things, but nobody wants to pay them.  What's crazy (from the point of the conspiracy lot) is that most of the research into alternatives is being funded by "Big Oil" and "Big Auto", who are the same ones accused of covering up the research.  Of course, it's all been published and put out in the open.

Now, to address your question about fuels:

Yes, hydrogen is pretty much a waste of energy, and research.  When used in a fuel cell, it is about as energy efficient and polluting as a hybrid.  When used in a combustion engine like the Hydrogen 7.... it's money (and energy) out the muffler.  There was a good article/letter in Chemical and Engineering News.  I think the August 4, 2003 issue, or sometime around then.

http://www.communitysolution.org/fcf-11....

Hydrogen is the only non-carbon "fuel", without getting into batteries and fuel cells.  Our options for carbon-based alternatives to petroleum are biofuels.  A biofuel is simply any fuel produced from an agricultural or farmed source.  In a sense, even petroleum is a biofuel... just one that's been stored away for a very long time.  Chemistry is a wonderful thing, and we can make pretty much anything from anything.  The only issue is how efficiently we can do it.

For plant oils, the most efficient option is biodiesel.  For starches and cellulose, we have several options, although one is not a motor fuel, per se:

1) Ethanol (from fermentable sugars and starches)

2) Ethanol (from cellulose)

3) Gasoline and Diesel (from synthetic oil made from cellulose)

4) A furnace (just burn it and make electricity)

And batteries:

Battery powered vehicles are definitely the most efficient, but until Lithium Ion batteries, the energy density just wasn't there to give them all that good a range.  For short daily commutes (50 miles or less) they worked OK, but most people needed more than that.  Also, in a single vehicle family, it just isn't a good option.  Now with EVs pushing 200 miles on a single charge, they are becoming a valid option, even for the single car family.  Of course, the initial price is still quite high.  They only use 1/3 to 1/4 of the energy (and therefore cost), but that difference is hard to justify the initial outlay.  For example, if a person commutes 70 miles a day with a compact gasoline vehicle, or similar sized EV:

70 miles / 35 mpg = 2 gallons per day = $8 per day.

21 kW hr * $0.12 per kW hr = $2.60 per day.

Take 50 weeks, 5 days per week; difference is $1,350 per year.  It would take ten to thirty years to justify the $10,000 to $30,000 difference in initial price.  And the price of electricity will go up roughly with the price of gasoline (but not quite as fast).  Hopefully, that cost issue will come down, but Li-Ion and NiMH batteries have been the same price for a while now.

There are also zinc-air fuel cells, which use metallic zinc as fuel.  The fuel cells can operate as rechargeable batteries, or the zinc oxide slurry can be drained out, and turned back into zinc.

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And the depressing bit.  Only about 20% of our oil use is for daily commuting in a personal car.  It would take about 25% of our agriculture to replace that with biofuels.  By joining biofuels (used in electric plants) and EVs, we might be able to offset that oil use with 10% of our agricultural lands.  A small wind turbine or 160 sq ft of photovoltaics could recharge an electric commuting car, so it might even be possible to replace 20% of our oil use without any agriculture.  But that only takes care of 20% of our oil use, and it's a lot of effort.

Answer 2

The best is electric.  See the links below for explanations.