I agree with most of that and I'll add a few comments:
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Originally Posted by J_D
There will be no major shift away from oil as the worlds predominant transport fuel. The price will just continue to increase until we cut consumption. All the so called "alternative" fuel sources will continue to be bit players for quite a while yet. We currently have no alternative fuel source that is as abundant as oil.
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Yep.
Lets run through the alternatives.
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Ethanol: Ethanol is already becoming a problem rather than a solution because most of the worlds ethanol is currently produced using food crops, which means someone goes hungry so you can fill up your SUV. The current demand in the US for corn as a feedstock for ethanol production is already resulting in driving up the price of Mexico's staple food. If the process for turning any biomass into ethanol is perfected and made economical this would alleviate demand on food supplies and increase the potential feedstock available for ethanol production but the world currently uses about 80 million barrels of oil a day so production would have to be on a massive scale to make a major dent in the use of oil. There is also a lot of debate going on at the moment about whether ethanol is actually net energy positive. Generally speaking every barrel of oil we currently extract from the wells in the middle east uses about 5 to 10% of that barrel of oil to extract and refine. The mere fact that there is currently a question mark over the net energy balance of ethanol suggests that it isnt a very good fuel to use and will only make a minor difference to oil use.
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The food issue is real, as is the increased demand for land to grow the feedstock crops. Both of those are alleviated when non-food feedstock is used. That is currently an economic issue rather than technical. Water to grow the crops is also a real issue.
An integrated approach using food "waste" is certainly worth pursuing. That is the primary reason that Manildra produces ethanol in NSW; it is a means of extracting value (or avoiding a disposal cost) from the waste left after starch and sugar products are obtained from wheat.
As it stands now, the total energy balance is less significant than the source of the energy used. If natural gas and coal are used to grow and extract the ethanol, it may be viewed as a way to convert those energy sources into a fuel suitable for use with our current vehicle and infrastructure technologies and investment. Cellulosic ethanol is much more obviously energy +ve and there is scope for improving the plants (legume type N2 fixation for eg.) as well as the fermentation processes.
Ethanol is a safer bet than other alternatives because to some extent, a fermentation vessel (with different micro-organisms) can be used to produce from biomass some of the chemicals that we currently get (cheaply) from oil. If ethanol doesn't play out (and it's better than most alternatives) switching to produce something else may be an option so the investment isn't wasted.
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Hydrogen: First up hydrogen is NOT a fuel source, it is a battery. Hydrogen isnt abundantly available in nature except when its attached to oxygen, the process of liberating the hydrogen from the oxygen(electrolysis) uses a lot more energy than the resulting hydrogen contains. The laws of physics say you cant get more energy out of the hydrogen than the electrolysis uses in the first place, so the only way hydrogen will become a major fuel source is if the world builds a LOT more power plants, these would have to be nuclear because using coal would produce more pollutants than burning oil, and we all know how much the world loves nuclear power.
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Agreed, Hydrogen just isn't going to happen in any of our lifetimes. There is simply too much infrastructure - new vehicles, production, design, repair and use - required for it to work any time soon, even if it was ready to go now (it's not). There is also going to be significant increase in demand for electrical energy for other uses.
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Biodiesel: Youve seen the stories on TV "My diesel vehicle costs 20 cents a week to run off used chip fat". Works well when only a few people are doing it but as soon as everyone else jumps on the bandwagon there isnt enough used chip fat to go around and crops have to be planted to produce the biodiesel, using up precious arable land for fuel production and resulting in ever higher food prices and more starving people.
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Worse than ethanol in that a much smaller portion of the plant (or algae?) is used. Maybe if it was integrated with food or ethanol production, it's better than throwing stuff away.
Liquid fuels are going to be necessary for agricultural production (no 4km extension leads or dragging tons of battery packs around) so biodiesel (and ethanol can be used as the short chain alcohol in ester based biodiesel) is worth pursuing on that basis.
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Electric cars: Aside from the fact that you would have to build a massive number of nuclear power plants to run a fleet of electric cars most of the oil a car uses is used before you even drive it off the car lot. All the plastics used in the car and the energy used in its production add up to more oil than the car will use on the road during its lifetime and batteries only add to this hidden oil consumption. As we all know rechargeable batteries have a limited useful life(about 3-5 years). The oil consumed producing a new battery pack for an electric car every 3-5 years would easily use more oil than a petrol car would over the same time period.
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There are also issues with the materials used to make the batteries as some of them may be difficult to find and in demand for other uses. "Peak Lithium"? Not much use for shipping either.
The electrical demand problem applies here too.
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Alternative fuel sources and subsidies avoid the real issue which is efficiency in the use of oil. Subsidies would be better placed into creating an efficient and free public transport system to decrease the number of people using private vehicles to drive to and from work.
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Jack the tax up on the oil sourced fuels. If people still want to use it, and pay for it, they can. If they want to use it they will use it more efficiently. The alternatives will also look better economically. With increased efficiency, the alternatives become more viable too; eg. the land/water use issue is lessened.
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The good news is the world isnt going to run out of oil. We have an abundance of the stuff, the problem is the oil that is left is getting harder(and thus more expensive)to extract. The world will continue to be run by oil at least for another generation, we just have to use this resource more wisely and efficiently.
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Ultimately, it will run out though, so we do need to look at replacement energy sources. And so far, any discussion around CO2 release has (intentionally) been ignored. The role of govt., via subsidies or taxation, needs to be to smooth the transition to the more efficient use and any alternatives.