http://en.wikipedia.org/wiki/Energy_returned_on_energy_invested
In physics <http://en.wikipedia.org/wiki/Physics>, energy economics <http://en.wikipedia.org/wiki/Energy_economics> and ecological energetics <http://en.wikipedia.org/wiki/Energetics>, *energy returned on energy invested* (*EROEI* or *ERoEI*); or *energy return on investment* (*EROI*), is the ratio <http://en.wikipedia.org/wiki/Ratio> of the amount of usable energy <http://en.wikipedia.org/wiki/Energy> acquired from a particular energy resource to the amount of energy expended to obtain that energy resource.[1] <http://en.wikipedia.org/wiki/Energy_returned_on_energy_invested#cite_note-mh2010-1> [2] <http://en.wikipedia.org/wiki/Energy_returned_on_energy_invested#cite_note-eo-2> When the EROEI of a resource is less than or equal to one, that energy source becomes an "energy sink", and can no longer be used as a primary <http://en.wikipedia.org/wiki/Primary_energy> source of energy. On Sat, Jan 17, 2015 at 12:46 AM, H Veeder <[email protected]> wrote: > > I am not sure what Piantelli meant, but even if the magnitude of the heat > anomaly is real, can we say with confidence that "cold fusion" will be a > cost effective means of generating energy, i.e. will the energy required to > a manufacture a "cold fusion" reactor be significantly less than the energy > it can produce? > > eg. Oil is a cost effective means of generating energy, because the energy > required to extract one barrel of oil from the ground is significantly less > the energy produced by burning one barrel of oil. > > > Harry > > > On Fri, Jan 16, 2015 at 8:58 PM, Jed Rothwell <[email protected]> > wrote: > >> I guess Piantelli said this . . . or there is a misunderstanding. >> >> Axil Axil <[email protected]> wrote: >> >>> [Piantelli?] also spent a lot of time on the all important matter of >>> credibility in claims. Principally about the HUGE amount of energy that can >>> be stored in various forms of Hydrogen and that must absolutely be excluded >>> before any meaningful conclusion could be had about anomalous heat. >>> >> What is that supposed to mean? It isn't all that huge. It is the heat of >> formation of water, 285,800 joules per mole. That is the most energy-dense >> chemical reaction there is. Palladium holds more hydrogen than any other >> hydride. In my book, I computed how much hydrogen 0.2 g of palladium can >> hold when loaded 100% (which no actual hydride can achieve) will produce >> 286 J: >> >> ". . . 0.2 grams = 0.002 moles of Pd. Fully loaded at a 1:1 ratio with >> hydrogen, 0.002 moles of Pd hold 0.002 moles of H (0.002 grams) which >> converts to 0.001 moles H2O. The heat of formation of water is 285,800 >> joules per mole. It is very difficult to load as high as 1:1, except at >> very low temperature. The palladium cigarette lighters would have achieved >> no more than a 1:0.5 ratio in a mixture of alpha and beta loaded Pd-H. In >> other words, a 1 ounce (28 gram) palladium lighter would hold roughly as >> much energy as 20 wooden matches." >> >> That's 1,430 J/g. A few 1 g samples of palladium have produced 50 MJ and >> more. 50,000,000 is a lot more than 1,430. It is easy to see this is not a >> chemical reaction. >> >> He talked about ionisation, absorption, re-combination, para and ortho >>> and various charge states etc. >>> >> These changes cannot produce more net energy than the formation of water. >> That is the absolute upper limit to what a hydride can produce. 1430 J/g. >> No chemical system can produce more than ~4 eV/atom which is close to what >> the heat of formation of water is. >> >> >>> Just ionisation energy of 1.008 g (1 mole of Hydrogen) is 1,312 >>> kilojoules, the re-combination is 423 kilojoules and so on. >>> >> That would make great rocket fuel if you could store it! NASA would pay >> you a billion dollars and you would get a nobel prize. But no one can. As I >> said, the upper limit is 285 kJ and that's for 2 moles of H (and one of O). >> That's why NASA used H2 and O2 to power the space shuttle. There is no >> better fuel measured in energy per gram. >> >> You can subject a mole of hydrogen to a laser and make it real hot for a >> nanosecond too, but that doesn't count. That is not energy storage, and you >> cannot release that in any system. >> >> If Piantelli said this, he has a screw loose. >> >> >>> Without a full account of the amount of potential hydrogen in a >>> reaction, results are a fantasy and will not be taken seriously. >>> >> The full account is what I said: 285 kJ per 2 moles. End of story. NASA >> and every automobile maker on earth will pay you billions if you release >> more energy than that. >> >> - Jed >> >> >
