Originally Posted by Don Baldwin

And the point I'm making is...it takes MUCH more energy to MAKE your batteries than you'll EVER get out of them. You can't just FORGET all the energy it took to build your air conditioner...AND you can't just forget ALL the energy it takes to build a battery.



The ONLY reason you CAN think this way...so nonchalantly about "energy" and "work" is that oil and gas are basically free. ONLY with oil/gas do you get back 100X the energy you put into getting and using it.



"A barrel of oil contains about six gigajoules of energy. That’s six billion joules or 1667 kilowatt-hours. No, we don’t have any idea how much that is, either, so let’s think about the equivalent. Sit a reasonably healthy male adult – let’s call him Jim – on an exercise bike wired to an efficient generator, and he can produce 100 watts for you. So after Jim has pedaled an hour he’s produced 100 watt hours of energy, or 1/10 of a kw-hour.



To produce the same energy as that in a gallon of gasoline, 33 kilowatt-hours, Jim would need to pedal 33 X 10 = 330 hours. We need to be legal, of course, so Jim only pedals 40 hours per week. Jim’s desperate, so let’s assume he agrees to take no breaks and never stops working to chat at the water cooler or to check in with his friends on Facebook. He pedals straight through for 40 hours per week. He will have pedaled enough to equal the energy in a gallon of gasoline in a little more than eight weeks. Because Jim’s desperate, he gladly works for minimum wage, so your energy equivalent of a gallon of gasoline is a bargain at $6.55 X 330 = $2,194. How’s the price of gasoline lookin’?



Jim likes working for you, so let’s ask him to pedal long enough to produce the same energy as that in a barrel of oil, 1667 kw-hours. Easy to figure. 1667 divided by 1/10, or to say it another way, 1,667 X 10, or 16,667 hours of pedaling. That’s 417 weeks. Jim must love pedaling that bike, because he never takes a vacation. Jim will have pedaled enough to produce the energy in a barrel of oil in 417 divided by 52 = 8.01 years. Congress has cooperated with you during this entire adventure and kept the minimum wage stable at $6.55 per hour, so your energy equivalent from Jim will cost you only $6.55 X 16,667 = $109,169."



"If this is true, oil is essentially “free” energy at the current price. I decided to check it out, as the claim seemed a little hard to believe at first.



After some quick calculations from first principals (see below), I found that for a purely theoretical task, like heating water with a pedal powered generator, the claim is correct. It would indeed take 12 years of laboring to produce the same amount of heat energy as a single barrel of oil."



You CANNOT simply "replace" oil with ANYTHING short of a "Mr Fusion" from Back to the Future.