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More "Miles Per Acre" From Bioelectricity Than Ethanol
CarnegieScience writes "Scientist calculate that, compared to ethanol used for internal combustion engines, bioelectricity used for battery-powered vehicles would deliver an average of 80% more miles of transportation per acre of crops, while also providing double the greenhouse gas offsets to mitigate climate change."
Miles per acre? What's that in rods per hogsheads?
As a bunch of (electric) eels tied with electric cord??
how long until
The problem with using biomass to generate electricity to run cars is that you've got to get the electricity into the car and store it there, usually in a lithium-ion battery. That whole process probably diminishes your efficiency by an order of magnitude. If this guy's taken all that into account, well, so far so good. But I think we're going to need literally quantum advances in energy storage technology (think molten salts and carbon nanotube supercapacitors) before we can get fossil fuels completely out of our transportation system.
The real advantage of producing ethanol right now is that you can just mix it into gasoline and sell the combination fuel (E85) for use in most post-2004 model year cars. It doesn't require a total revamp of the energy distribution network for vehicles.
...now all we need is a fuel that comes in the form of a long string, and we can finally express fuel efficiency as a dimensionless number.
BTW, 20 miles per gallon works out to 3.4409911e+10 inverse acres. Or, to look at it another way, one gallon per 20 miles is 2.9061395e-11 acres, or about 0.12 square millimeters. That's the diameter of the imaginary thread of gasoline that your vehicle is gobbling, Pac-Man-like, as you drive down the highway.
Comparing energy production density to Corn-based Ethanol is like stealing candy from a baby. Corn-fueled Ethanol has a tough time doing much better than just burning fossil fuels outright in systemic carbon footprint, and in some studies, is actually WORSE than strictly burning gasoline/oil.
Yes, the average is a net improvement of anywhere from 25% to 70% return on investment, but even then, you have to consider the value of the farmland itself! We'd probably do much better by simply growing wild grass on prime farmland, harvesting it, and burying it, when looking in terms of carbon footprint!
So saying that NNN technology is X% better than bioethanol is like saying that doing X is less painful than scraping off your penile foreskin with a cheese grater.
Truthful, but not very useful. Come back when you have something that actually works. For example, what's the benefit of bio-electricity over Photo-voltaics? Now that the latter technology is down to (or better than) $1/watt, this becomes a very, very tough technology to beat, and actually works better on craptastic, rocky soil off in the desert someplace with 3 inches of rainfall per year.
Meaning, we can get back to using farmland for growing food, and stop with this silly "let's raid the kitchen cupboard to feed our guzzling SUVs!" craze that's been on for the last few years.
I have no problem with your religion until you decide it's reason to deprive others of the truth.
Food crops as energy sources was never a good idea, we didn't breed them for their modern harvestable energy content, and even if we did we'd be offsetting fuel crops. Algal Oil is a MUCH better biofuel solution as it can be build anywhere you have the following things:
A) Land [cheaper the better] .. so cannot pull it straight from the air, have to filter it.. but pretty much everywhere]
B) Source of Water [doesn't neccesarily need to be fresh or particularly clean, in fact fertilizer polluted water might even be a good thing]
C) Source of Carbon Dioxide [clean CO2
D) Sunlight
And it already works, we have "pilot plants" already cranking it out.
Don't have to offset prime forest or prime agricultural - vast stretches of the semidesert southwest would be usuable.
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We can get fossil fuels out of our energy system right now with drop in non-fossil replacements like Algal Oil [ see my discussion of it in this thread http://tech.slashdot.org/comments.pl?sid=1225951&cid=27864987 ]
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Agreed... pump em full of Algal Oil produceed biodiesel... instant carbon neutrality [assuming all energy used for pumps, etc in the production plant is carbon neutral which can be done]
That's the nice thing about using Algal Oil as a drop in replacement for fossil oil - it's chemically identical but all that carbon in it was sucked out of the atmosphere.
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I'm driving a home-converted electric car right now. I didn't even choose my components for efficiency, and according to my kill-a-watt meter, I'm still running more than twice as efficient as an internal combustion engine.
There have been several studies comparing overall efficiency, including power transmission losses. The EV wins every time.
For geek dads: Contraction Timer
Morpheus: "The human body generates more bio- electricity than a 120-volt battery and over 25,000 B.T.U.'s of body heat."
Now we just need some poor saps to lock into an energy-harvesting pod while we jack their mind into The Sims 24/7... actually that sounds like a special kind of hell. Perhaps we can give them their choice. Some might choose to live in WoW 24/7... actually some choose to live in WoW 24/7 -already-... perhaps they would be the first to volunteer! It's like getting corporate sponsorship AND never having to shower again, WIN WIN!
"I Don't Have Enough Faith to be an Atheist"
The real blow-it-out-of-the-water numbers are when you eliminate "bio" from the equation, period. Corn yields 300-450 gallons of ethanol per acre. Sugarcane, about 550-850 gallons or so. Switchgrass can theoretically yield over 1000 gallons per acre and algae 5000, although those numbers are likely to get way smacked down by reality (especially the algae numbers). But let's just go with them. CAFE average is ~24mpg, and you get less mpg on ethanol, but hey, let's just say our cars get 40mpg. The average driver goes 12k miles per year, so corn can support 1.3 drivers/acre, sugarcane 2.3 drivers/acre, switchgrass 3.3 drivers/acre, and algae a way-over-optimistic 16.7 drivers/acre.
A compact linear fresnel reflector solar thermal generating station produces about 1MW nominal capacity for every 4 acres and has about a 20% capacity factor (in non-optimal sites). That's an actual MW per 20 acres, or 488,288,000Wh/acre-year. The Volt and Tesla Roadster both use about 200Wh/mi, so let's go with a more pessimistic 300Wh/mi after losses and with less efficient designs. That's 121.7 drivers per acre. I.e., it beats the pants off even the highly speculative numbers for algae. And it uses no water or fertilizer -- and we use *way* too much water as it is.
If you want land efficiency, converting the sun directly to electricity and using that electricity directly rather than having the intermediary stage of "plants" is the way to go. And we farm too darn much of this planet as it is already.
You're not made of Tuesday!
Aglae can produce oil instead of ethanol. Oil that can be treated just like light sweet crude at the refinery, with a lot less impurities [so it's easier to refine].
So to not do something stupid like Algae Ethanol and do Algae Oil the biggest advantage is it's a potentially carbon neutral drop in replacement that can be used in existing gasoline and diesel engines.
If you can get efficient storage of electricity (like hopefully EEStor isn't full of it) a pure-eletric system will be better - but at the same time we can cut our greenhouse gas emissions massively by using Algal Oil as a drop in replacement for fossil oil.
Now as gas/diesel demand drops down in about 50 years we can do other things with that algae production infrastructure I'd imagine.
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Of course, the obvious NEXT questions are annoying things like:
1. What kind of numbers do you get with nuclear and/or fusion reactors, instead of biomass reactors or cornfields?
It is worth mentioning that the MIT Nuclear Engineering senior project recently was the engineering design of a fusion reactor to produce hydrogen for automotive fuel. One of the reasons given for producing hydrogen rather than electricity is that we don't have anything remotely resembling a power grid in the Northeast that could handle the output of a commercial-size fusion reactor.
And their design was apparently conservative: you could build it, starting TODAY.
2. How do you distribute the electricity from your biomass reactor or your solar field to the cars? See previous paragraph about power grid issues.
Hydroponic Algae is several orders of Magnitude less complex than Hydroponic food crops.
Algae is a free floating aquatic plant so a lot of the labor intensities go away in the blink of an eye, and it has a higher plant density than hydroponic corn.
Hydroponic Wheat/Corn/etc is more expensive because it's wasteful and increases the energy costs associated.
Need to separate your Algae from the water? Sieve.. isn't so simply for corn, etc as they have to sit in racks and only their roots are being bathed and all kinds of other complexities.
All you need to grow hydroponic algae is water circulation, sunlight, carbon dioxide and some nutrients in the water [clean up fertilizer polluted water anyone?]
and the "wear and tear" on transparent plastic tubes that simply have algae-bearing water running through them isn't going to be nearly as bad as other hydroponics.
In short: bad comparison.
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Algae is a free floating aquatic plant so a lot of the labor intensities go away
Hydroponics isn't expensive because of labor. The labor on a hydroponic farm is, if anything, lower than on a conventional farm. It's expensive because of the massive amount of plastic and steel that you need. You're talking endless *acres* of plastic. And all plastics suffer UV degradation to some degree.
Hydroponic Wheat/Corn/etc is more expensive because it's wasteful and increases the energy costs associated.
Hydroponic *everything* is expensive because of capital costs. Staples are simply not grown in hydroponics because nobody wants to pay a fortune for them. The only things that are generally economically justifiable to grow in hydroponics are things that are *already* expensive due to labor costs.
Sieve.. isn't so simply for corn,
I take it you've never heard of a combine.
Again, it's not the harvesting that's the issue. It's not marginal costs at all. It's capital costs.
All you need to grow hydroponic algae is water circulation, sunlight, carbon dioxide and some nutrients in the water
You've made it obvious that you've never done hydroponics in your life.
and the "wear and tear" on transparent plastic tubes that simply have algae-bearing water running through them isn't going to be nearly as bad as other hydroponics.
Again, you make it quite obvious. UV creates free radicals in the plastic which causes crosslinking, making the plastics brittle. It happens in all plastics. Untreated thin film polyethylene (the cheap stuff) generally lasts for under a year before it becomes semi-opaque and so brittle even the stresses of a light breeze can break it. About the longest you'll get is thick, rigid, UV-treated polycarbonate, which is probably good for about 10 years in this kind of role, but I doubt they'd even dream of paying for that. They'd probably go with UV-treated PVC thin film tubing, good for 2-3 years. Or they might use some sort of fluorinated thin film. But that's still monstrously large capital costs for this kind of coverage, for such tiny revenue per acre (~$10k/year).
You're not made of Tuesday!
Whether or not EEStor is real or not is becoming increasingly unimportant. When they first started pushing their (questionable) tech, conventional li-ion cells on the market were 160Wh/kg and most of of the stable ones were ~$1/Wh and under 100Wh/kg. Now conventional li-ion cells are 200Wh/kg with longer life, the stable ones are under $0.50/Wh and rapidly headed toward $0.35/Wh or so, and there have been literally dozens of lab breakthroughs that if any one of each anode and cathode tech were commercialized, would make li-ion cells have the claimed energy density of EEstor's EESU. So, honestly, I don't really care all that much about whether they're legit or not anymore.
Hydrogen is already obsolete. I mean, come on, 6 figures for a fuel cell stack strong enough to run a car? 1/3rd the efficiency of EVs, and that's *if* you use fuel cells rather than combustion? 5 year fuel cell lifespans, tops? Many more moving parts (including a compressor)? An explosive, ozone-depleting fuel that leaks through almost anything, pools under overhangs, has a ridiculously low ignition energy, burns in almost any mixture with air, rapidly undergoes deflagration to detonation transitions, etc? That has no better range than a modern li-ion EV? And takes 3 times as long to fill as the high end rapid-charging EVs and 1.5 to 2x as long as the low-end rapid charging EVs? Why exactly is this supposed to be appealing?
You're not made of Tuesday!
i know the phtysics of UV degrading plastics, but then again most of the applications im seeing aren't using your normal plastics. They seem perfectly capable of turning a profit.
As for yuor "blah blah combine" combines don't exactly work on HYDROPONIC CROPS...
Yes you have some valid points about wear and tear, but apparently all analysts and people experimenting with it think that at $50/barrel that Algal Oil is perfectly economically viable.
BTW: bioplastics.
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And their design was apparently conservative: you could build it, starting TODAY.
No one has demonstrated sustained useful greater than unity energy yields from fusion outside of bombs and stars. It is entirely possible that their design would work, but the track record of fusion attempts says its unlikely. Now don't get me wrong, I'm all in favor of fusion research, and I think it's worth spending money on. But, when the fundamental concept your engineering project relies upon has not been demonstrated in a manner that obviously scales to your project, calling it conservative is a stretch. In fact, calling it engineering is a stretch -- it's scientific research. Once they have a scale model and *strong* reason to believe it will scale properly, then you can call it a viable design -- but until it or something like it has been demonstrated at scale, you can't call it conservative.
"Shipping is responsible for 3.5% to 4% of all climate change emissions" from same article
It's not the carbon emissions that are the real problem with cargo ships, but the NO and SO pollution. As far as I can tell, these are not greenhouse gases so much as carcinogens. While, yes, they do need to be reduced, your post was very misleading in implying that the majority of air pollution and climate change comes from cargo ships. It doesn't.
You were very generous with 40mpg. The highest mileage a 2009 car gets on E85 is only a paltry 16 city 23 hwy, much lower than the 22 city 32 hwy on gasoline. Most new vehicles that burn E85 are trucks so the cafe average is probably closer to 13mpg, which would be worse if running on E100.
http://www.fueleconomy.gov/feg/byfueltype.htm
plants are only about 6% efficient(max) at converting sunlight into sugars & cellulose. Modern solar panels are around 20% efficient(very expensive space panels are at 40%).
ethonol must be distributed by truck or rail(there is no pipeline yet).
electricity transmission loss is around 3%.
How you use the energy matters also. Internal combustion engines waste most of the energy as heat(75-80%) and use only 20-25% of the energy to move the car. Electric batteries and motors are around 85% efficient.
Electricity wins.
Now if we can just get some affordable batteries and solar panels...
We have the best government that money can buy.
Wait. Corn? Switchgrass? I thought bio-electricity was about breeding electric eels.
Too bad "Put an eel in your tank" has a completely different connotation from "Put a tiger in your tank."
We are the 198 proof..
Where does this notion come from? No, seriously. Current electric cars are about the same weight on average as current gasoline cars (they tend to be heavier than other cars in their class, but the lighter classes are overrepresented currently, so it's about a wash). Same amount of material, and therefore.... they're somehow incredibly resource hungry? Where does this come from?
Or is the notion that batteries somehow consume incredibly rare resources? You're thinking of fuel cells, which take platinum (trivia: so do catalytic converters). For example, one of the most popular chemistries for EVs today is lithium phosphate. It's made of lithium salts (which are so abundant that their prices generally range from $4 to $8 per *kilogram*, and which are available at essentially limitless quantities in the oceans for $20-35/kg), phosphoric acid (one of the world's most common industrial chemicals, and found in soft drinks), sugar, iron powder, a porous polyethylene membrane (polyethylene being one of the cheapest and simplest plastics), graphite or amorphous carbon, and bulk electrolytes (formulations vary), plus casing, wiring, etc. What exactly in this mix are you seeing as incredibly rare? The cost of lithium phosphate batteries (and spinel cells as well) are predominantly capital costs, not materials costs.
You're not made of Tuesday!
Oh come on, not this lithium scarcity nonsense again....
You're not made of Tuesday!
1 mile per gallon (imp) = 59.95 furlongs per firkin (US)
should be:
1 mile per gallon (imp) = 52.46 furlongs per firkin (US)
if it actually matters to anyone, that is...
Those who can make you believe absurdities can make you commit atrocities. - Voltaire