and wind power at my home. When, this wasn’t (sufficient) to meet my needs perhaps I could “plug” my hydrogen generator into an electric power supply (yes I would be paying for the electricity BUT I would be cutting out all middle men, refineries ect). Can’t Hydrogen be generated from water with a simple electric current? Also, don’t the Hydrogen based ENGINES already exist? I keep hearing that it is distribution of the Hydrogen around the nation which is the big obstacle. Couldn’t this point source solution solve much of the distribution problem (that is to say people generating much of their own Hydrogen). Imagine the FREEDOM of not depending upon the Middle East, Exxon or even the gas station down the street for your power. One might even be able to largely go “off the grid” with sufficient solar and wind power generation.
(that was before my animal rights days). Why, couldn’t this same principal be utilized to exponentially INCREASE the efficiency of solar power generation? Thus, magnifying “lenses” would be placed over my photo-voltaic, solar cells to increase their UV exposure rate. For that matter couldn’t a SERIES of lenses be used to heat increase the energy even more? If this would “overwhelm” the cells perhaps it could be directed at water which would then generate steam (which would drive a turbine) instead.
The problem with Hydrogen is not distribution but production. Here’s a recent SD thread on the topic (found via search):
Hydrogen powered cars: What’s the Straight Dope?
possible, just inefficient. Like I said my “home system” would use electrolysis and would use sun, wind, and regular electricity in that order. The BIG advantage is that you would control your OWN supply of “gas”. No need for filling stations, OPEC, . You WOULD need a scource for the necessary solar, wind, and electric Hydrogen gas generators as well as maintenance.
My car already runs on hydrogen. It’s called gasoline. There’s more hydrogen in gasoline than liquid hydrogen.
Forget about PV arrays, pure hydrogen, etc. They’re energy vessels, not fuels.
in sight. Also there is something to be said for having a “clean” fuel. There is even more to be said for “getting of the grid” and being able to supply your OWN energy needs (or at least MOST of your own energy needs). Heck, when I’m camping in the Summer IF I had wind and Solar power, I might even be able to sell energy BACK to the electric company. It’s about freedom as much as anything.
Agree. But when you look at the big picture (production, distribution, etc.) hydrogen “fuel” is not clean burning. Neither is alcohol.
Lots of people have “gotten off the grid.” While it may provide a feeling of freedom, keep in mind that you’ll be paying much, much more per kilowatt hour if you use PV arrays.
Hydrogen is not clean-burning. Or rather, the hydrogen itself is, but the coal you probably used to produce the hydrogen produced tons of CO[sub]2[/sub]. Now, burning coal does have the advantages that it’s done on a large scale at a single location, so emissions are easier to control, and the United States has a lot more coal than oil, so at least we’re not as dependent on foreign oil. But it’s far from a panacaea.
As to magnifying glasses on PV arrays, you’re still limited by the area you have available. If your arrays are on your roof, then you’re limited to the amount of sunlight hitting your roof. To get twice that amount, you’d need magnifying glasses totalling twice the area of your roof.
Why would you burn coal to make hydrogen? Most commercially produced hydrogen today is made from natural gas, a resource we have in abundance. Hydrogen is a fossil fuel.
Specifically, I am arguing for a “point source” (and that is KEY) solar/ windpower solution. Unfortunately, I’m just not knowledgable enough about the technology to know how much power (on average) can be generated with your average solar/wind array (and thus how much Hydrogen can then be generated via electrolysis). IF it is significant and not cost prohibitive (or could be made less prohibitive via mass production) here is how my program might work:
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Government offers some significant dollar for dollar TAX CREDIT for any homeowner that installs my solar/wind/ hydrogen generator.
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Even without the Hydrogen genearation part the wind/solar equipement could be used to generate electricity for general residential use (to lessen the drain on the grid).
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At the same time the government offers a monstrous incentive to the first automaker who can make and SELL one million Hydrogen powered auto’s to the public (maybe the incentive would be ten years without having to pay corporate income taxes or something equally worthwhile).
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In addition, anyone who generated EXCESS hydrogen (via the above or any other acceptible method) could sell it TAX FREE on a Hydrogen Exchange. For instance, I will one day inherit a three hundred acres in Nevada about a hundred miles North North East of Vegas. Perhaps I might put THOUSANDS of wind/solar hydrogen generators on my otherwise mostly useless property and somehow sell the “product” on the exchange. Even people with lessor space in less ideal locations (with regard to sun and wind) might be able to do this to some degree to earn extra income.
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In addition, there would be a concerted effort to fund a Hydrogen distribution system to supplement the above measures.
The tough part is the creation of the integrated solar/ wind/ Hydrogen generation and storage units. Is the technology currently available to even consider doing this?
One amp of current is 1 coulomb of charge passing a given point per second. A coulomb is roughly 6x10^18 unit charges.
One mole of any gas is Avogadro’s number (roughly 6x10^23) of atoms. When electrolyzing water, you are crudely doing:
2 H[sub]2[/sub]O + 4e- = 2H[sub]2[/sub] + O[sub]2[/sub]
Therefore, you would need 10K coulombs per gram of hydrogen. (more precisely, Faraday’s number [F] or 96,485.3 C/mol) This would be 1 amp of current for 26 hours 48 min, or 26.8 amps for one hour, per gram of Hydrogen gas produced (assuming I recall the electrolysis equation correctly). Voltage is not a key parameter, since you a mere 1.2 V will easily suffice. Solar cells are often made to generate higher voltage by wiring individual “cells” in series, but the natural voltage generated by most silicon cells (the most common type) is around 1.5V, so you could easily rewire a 12v 1 A panel to generate 10A at 1.2-1.5V
The solar constant at Earth orbit is crudely 2 cal/cm^2. At the Earth’s surface it’s a bit over half that. Since 1 cal = 4.2 J, 1A@1V = 1 W, and 1W = 1 J/sec, you should be able to calculate the theoretical limit of Hydrogen production by electrolysis with solar panel-generated electricty with the set-up of your choice. I’d cut that figure in half for a more reasonable real-world estimate
I hope that was the kind of answer you were looking for. I also hope I didn’t drop a subscript in the electrolysis equation. It’s late.
Nothing wrong with the principle. Communications satellites often have reflector panels attached to the solar panel.
The problem is that it would only work on sunny days. You can’t focus diffuse light from a hazy or overcast sky, and in some parts of the world, that’s all you get most days. Also, it would require a tracking device so that the focused light always falls on the solar cell. Not only is it expensive to make this device, but it also lowers durability and reliability. It would be expensive to maintain.
to run your average automobile. There is also the little problem of WATER (at least with regard to my future Nevada property!). Of course even in the Nevada desert if you dig deep enough there may be water down there somewhere. Actually, maybe this would work better in costal regions using salt water. IF we took this approach then we could add tidal current energy to solar and wind power (in fact don’t they have this type of electrical generation in The Netherlands or maybe I’m thinking of Sweden).