Comments

It seems many are convinced that burning corn ethanol is like taking food from the starving poor of the world. The reality is that the price of oil has more to do with food costs than the price of corn going from 1.5 a bushel to 8. As another commenter mentioned there is only a few cents worth of corn in a box of cornflakes. Robert Zubrin can make the case better than I can: "Food vs. fuel a global myth" http://archives.chicagotribune.com/2008/may/06/food/chi-oped0506fuelmay06 As for land use, very little land is actually used for corn production currently. Take a look at this graph: http://www.thenewatlantis.com/imgLib/20080520_DefenseofBiofuelsTableL.gif Which comes from this article also by R. Zubrin. "In defense of Biofuels" http://www.thenewatlantis.com/publications/in-defense-of-biofuels And the last thing we are doing is cutting down forests to grow corn. For the record, U.S. forest land has been on the RISE for the last 90 years; between 20 and 80 million acres higher than in 1920. We've added 9 million since 1987 alone... and were adding forest land at a rate 30% faster than we're harvesting them. (Paraphrased from "The Bottomless Well" page 160-161, check it out for the original citations.)

"3. Resistance (R) - a sort of friction that slows the flow of electrons." Which is not to say that the SPEED of those electrons are reduced, just the number of electrons delivered per unit time is reduced. I once had a tour of a hydroelectric dam and the young lady doing the tour said that the voltage was stepped up so as to make the electrons go over the wires FASTER! No... it's so that you don't need to use transmission lines a foot thick. "Because in contrast to direct current, the voltage in an alternating current is easily transformed to a lower voltage (see photo)." Until now! Thanks to the wonders of modern semiconductors it is now possible to step up and down the voltage of DC at will. This will allow the use of high tension DC transmission lines which are more efficient than AC at a given voltage.

It seems many are convinced that burning corn ethanol is like taking food from the starving poor of the world. The reality is that the price of oil has more to do with food costs than the price of corn going from 1.5 a bushel to 8. As another commenter mentioned there is only a few cents worth of corn in a box of cornflakes. Robert Zubrin can make the case better than I can: "Food vs. fuel a global myth" http://archives.chicagotribune.com/2008/may/06/food/chi-oped0506fuelmay06 As for land use, very little land is actually used for corn production currently. Take a look at this graph: http://www.thenewatlantis.com/imgLib/20080520_DefenseofBiofuelsTableL.gif Which comes from this article also by R. Zubrin. "In defense of Biofuels" http://www.thenewatlantis.com/publications/in-defense-of-biofuels And the last thing we are doing is cutting down forests to grow corn. For the record, U.S. forest land has been on the RISE for the last 90 years; between 20 and 80 million acres higher than in 1920. We've added 9 million since 1987 alone... and were adding forest land at a rate 30% faster than we're harvesting them. (Paraphrased from "The Bottomless Well" page 160-161, check it out for the original citations.) As for the energy balance of ethanol production, I think this article misses the point a bit (this article equates energy use with environmental harm, which is ridiculous). It's not the total energy balance that really matters the most; it is how much transportation fuel is required to make a gallon of biofuel. This is because our "energy crisis" is an economic one, where transportation fuel supplies have gotten tight resulting in oil prices to skyrocket. This, I believe, is the primary root of our current world-wide recession. If we are not getting more ethanol back than oil put into the process we are not stretching the oil supplies very well! AS for the CO2 balance, our priorities are misplaced if we are worrying about how much coal or natural gas was burned to make some ethanol. That can be solved easy enough by just using non-carbon energy in the stationary processes. (That's right, it's possible to use energy without harming the environment) What we need to be doing is filling the supply & demand imbalance any way we can in order to keep the price of oil down, even in the face of increasing demand around the world. If we don't, oil will peak without a replacement to make up for the decline in production and put us in a worldwide, and permanent, depression. That gets the priority because global warming would solve itself if nobody could afford to burn anything. (Wealth is directly proportional to energy consumption. Given that most of our current energy is from fossil fuels it stands to reason the poorer we are the less CO2 we will emit.) So unless we are willing to go back to the stone-age, or an agrarian society with the human population shrunk by 2/3 from starvation for lack of modern (energy intensive) agriculture, then we need to place our most immediate and grave threats first and deal with the long term and more uncertain threats in due time. We don't need to take steps backwards in environmental protection, but we certainly shouldn't be harming our economic well being for perceived long-term benefits that would be better solved when we are strong and stable economically. Corn ethanol isn't a silver bullet, but it has been proven to help BOTH the environment (less CO2) and our economy ($13 lower price of oil by adding to the supply side of the equation). We can continue that trend by gasifying biomass, trash, low-grade (cheap!) brown coal, and use stranded natural gas, to convert to methanol and other synthetic hydrocarbon fuels. Eventually, when we can afford the capitol expenses, we can use high temperature nuclear reactors to provide the necessary process heat to extract CO2 directly from the air, and combine it with hydrogen split from water (thermochemicaly), to manufacture any kind of hydrocarbon we want; for fuel, plastic, margarine, whatever. That is a long-term solution because electric cars will still be fighting the energy density problem for a long time to come. Despite what some think, batteries have been pretty much stagnate for the last century. The best rechargeables we have now are still vastly inferior to a tank full of hydrocarbons (gasoline, diesel, methanol, etc) feeding an I.C. engine. So even if you have "green" electricity to run your electric cars, their use will remain limited. Lol, was this "comment" long enough? Sorry about that... -Alan

"For a high-speed recharge, the car will also have onboard chargers that let you plug into any wall socket and charge up in 45 minutes." When I read this in the January issue I was floored that the Tesla people were still spewing this kind of nonsense. I've heard this from them before but was surprised to read it in Popular "Science." Surely someone knows ohm's law down there? I've only known it by heart since I was ten... Lets make it simple... any "ordinary wall outlet" can only deliver 80% of the breaker capacity without risk of tripping after awhile. So a 15 amp circuit can do 12 amps. At 120 V that's 12x120= 1440 watts. Or 1.08 kWh of energy in 45 minutes. That is a factor of 55 below the 60 kWh of energy a depleted tesla battery can hold. So to deliver that amount of energy in only 45 minutes you need to be able to draw at least 80,000 watts of power from that normal outlet. That's 667 amps if the you are running at 120 volts. Note that many homes have a 200 amp breaker for that whole house, which is only 48000 watts that you could possibly draw from a standard house hold hookup. It is simply NOT POSSIBLE to recharge in 45 minutes, and I would be surprised if you could recharge the battery that fast safety in any case. So It would take 65 hours to recharge that battery if your charging circuitry is 85% efficient and draws 12 amps. In order to recharge overnight you need to have a SPECIAL outlet installed in your garage, of the same capacity that many electric clothes driers would require. With that, you could recharge in 7.5 hours, if you drew 40 amps on a 240 volt circuit (9.6 kW's). That would be doable in most homes. Here's an even better way to look at it... spending 45 minutes charging from a normal wall outlet would get you just another 4 miles down the road, a tad bit short of the 240 mile range. Have I beat this horse enough? Can we all now agree that the Tesla CEO is either ignorant or a liar? It's not like this is terribly complicated. It took me 5 minutes to calculate that stuff but reading the claim was an instant howler. So my vote is that Elon Musk is just another liar. Apparently the guys down at PopSci are just ignorant, since they didn't follow that answer with "are you insane?" or "how do you plan on drawing hundreds of amps from a wall outlet?" -Alan