How do hydrogen cars give off less greenhouse emissions?
How do hydrogen based cars give off less greenhouse emissions? Technically, isn’t water vapor considered to be a large contributor to the greenhouse effect, even more than say CO2? Not to mention, won’t the energy from a hydrogen car have to come from a most likely oil based or coal based source, thus losing efficiency between the energy transfer and thus making these cars even less efficient from a global perspective? I do realize that the hydrogen cars may be more efficient from a combustion sense, which may raise the global energy efficiency, but by giving off water vapor, wouldn’t that just make global warming (I’m assuming it actually happens considering that most scientists believe it does) worse?
It’s whether or not there’s a net increase in the atmosphere. The idea behind a hydrogen economy is that the hydrogen is extracted from water from the environment, once recombined with oxygen it just becomes water in the environment again, no net increase. With fossil fuels, the hydrocarbons represent carbon and hydrogen that has been sequestered from our environment for millions of years, using the fossil fuel combines it with oxygen in our environment to form CO2 and H2O resulting in a net increase of CO2 and H2O in our environment as well as a net decrease in O2.
Of course, gasoline and diesel don’t have to be refined from fossil reserves, they could be synthesized from CO2 and H2O in our environment hence achieving the same zero net increase of a hydrogen economy, indeed that was the conclusion of Sandia Labs research into more efficient ways of producing hydrogen from H2O, the same methods used to extract H2 from H2O can be used to extract CO from CO2 and a mixture of H2 and CO can synthesize gasoline/diesel via the Fischer Tropsch synthesis.
Synthetic liquid hydrocarbons would have the advantage over hydrogen of not only being more compact, more stable and easier to contain but the advantage of working with the nearly one billion existing vehicles and with the existing infrastructure thereby avoiding the carbon footprint of new vehicle manufacture and of constructing a distribution infrastructure.
Synthetic fuels also have the potential for being carbon negative if biofuel to liquid processes like gasification/pyrolysis are used in conjunction with biochar carbon sequestration.
Being carbon negative is something a hydrogen economy would not achieve but ironically existing gas guzzlers could if we just changed how we make gasoline.
It is ironic that what most would consider the environmentally friendly option, that of hydrogen fuel cell cars, is actually not the most environmentally friendly option at all.
Hyrdrogen cars are (will be) big polutors. The burning of hydrogen leaves only water vapor as exhaust but…. the problem is the recovery, production and storage of hyrogen in the first place. Liberating hydrogen from water (the only practical option), requires as much energy as is liberated later when it is burned. In addition, the gas must be compressed and/or refrigerated for practical use. This requires a lot more energy. And… then there are the transportation and storage energy requirements. All of this results in a very inefficient energy usage system, in which all of the inefficiencies are met by burning conventional fuels or through nuclear power generation. In the US today, most electricity is still produced by burning coal or natural gas….. which result in large greenhouse gas emissions. If we were to start building nuclear plants again, it might be possible to reduce these sources, but it will take 20 years or more of investment and effort to change the basic equation. And… would you really be happier with an additional 200 nuclear plants operating around the country?
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Water vapour isn’t a "driver" in the energy balance of the earth. It is a parameters which contributes as a "feedback". The water vapor in the atmosphere depends on the energy levels. It has been studied and found that this adjustment of water vapour only takes 50 days.
If you were to remove CO2 the earth would be cooler and the atmosphere would contain less water vapor. If you were to add CO2 the atmosphere will contain more water vapor.
Water vapor from human thermal sources do not play a major role… think about it: the energy we use is less than 1 / 10 000 the solar input of energy.
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this is why hydrogen cars (or any alternative energy car) haven’t replaced regular cars yet (and won’t replace them before decades). there hasn’t been an alternative energy that is truly green and /or efficient.
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It’s whether or not there’s a net increase in the atmosphere. The idea behind a hydrogen economy is that the hydrogen is extracted from water from the environment, once recombined with oxygen it just becomes water in the environment again, no net increase. With fossil fuels, the hydrocarbons represent carbon and hydrogen that has been sequestered from our environment for millions of years, using the fossil fuel combines it with oxygen in our environment to form CO2 and H2O resulting in a net increase of CO2 and H2O in our environment as well as a net decrease in O2.
Of course, gasoline and diesel don’t have to be refined from fossil reserves, they could be synthesized from CO2 and H2O in our environment hence achieving the same zero net increase of a hydrogen economy, indeed that was the conclusion of Sandia Labs research into more efficient ways of producing hydrogen from H2O, the same methods used to extract H2 from H2O can be used to extract CO from CO2 and a mixture of H2 and CO can synthesize gasoline/diesel via the Fischer Tropsch synthesis.
Synthetic liquid hydrocarbons would have the advantage over hydrogen of not only being more compact, more stable and easier to contain but the advantage of working with the nearly one billion existing vehicles and with the existing infrastructure thereby avoiding the carbon footprint of new vehicle manufacture and of constructing a distribution infrastructure.
Synthetic fuels also have the potential for being carbon negative if biofuel to liquid processes like gasification/pyrolysis are used in conjunction with biochar carbon sequestration.
Being carbon negative is something a hydrogen economy would not achieve but ironically existing gas guzzlers could if we just changed how we make gasoline.
It is ironic that what most would consider the environmentally friendly option, that of hydrogen fuel cell cars, is actually not the most environmentally friendly option at all.
References :
http://www.sandia.gov/news/resources/releases/2007/sunshine.html
http://www.worldchanging.com/archives/007427.html
I know the technology for an hydrogen powered car is out there. If the owners of the knowledge are willing. It would 98 % pollution free and that’s all I know. We could have had it as early as 10 years ago.
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