|Subject: RE: COP vs Efficiency
(and MEG replication)
Date: Mon, 14 Jul 2003 19:25:49 -0500
Glad you are having some success; please keep at it.
Efficiency is defined as the total useful output (energy or work) divided by the total energy input.
COP is defined as the total useful output (energy or work) divided by only that energy input that the operator furnishes. It specifically does not consider any extra energy the active environment may input.
The solar cell takes all its energy from its active external environment, the solar radiation. For a typical cell, it wastes about 83% of the input energy, and only outputs 17% as much electrical energy into the circuit as was input to it in the sunlight. Hence its efficiency is rigorously 17%.
However, the operator inputs ZERO. Well, to calculate the COP, you place the output (some finite number W, for a real cell) in the numerator and the ZERO input by the operator in the denominator. COP = W/0 = infinity. It is perfectly normal to have a system taking all its energy from its external environment, having an efficiency below 50%, and still having COP = infinity. The windmill is one, the sailboat is another, and the waterwheel is another. All have efficiencies at about 50% or less, but also have COPs of infinity. You need to change your thinking so you clearly understand that no system has more than 100% efficiency, but it can jolly well have COP>1.0 or even COP = infinity, and that DOES NOT violate thermodynamics.
I brought this out because 90% of the electrical engineers do not understand it. Even a few physicists do not understand it.
We also try to give a little more science background, and point out that technically the solar cell thermodynamically is a nonequilibrium steady state (NESS) system. There is a fairly well-developed thermodynamics of such systems already known and utilized; Prigogine received the Nobel Prize in 1977, e.g., because of his contributions to the thermodynamics of systems far from equilibrium.
And yes, such systems are permitted to do several marvelous things. They can (i) self-order, (ii) self-oscillate or self-rotate, (iii) output more energy than the operator inputs (the excess is freely received from the external environment), (iv) output real energy that does real work freely, without any operator input (all the energy is freely input from the environment), and (v) exhibit negative entropy.
Item (iv) is that COP = infinity area. Item (iii) is that 1.0<COP<infinity case. Items (i) and (v) have to do with free energy and production of negative energy (changing the form of some lost or uncontrolled energy so that control iand usage s regained). Every charge in the universe, e.g., consumes positive entropy from the virtual photon gas of the vacuum, coherently integrates the virtual energy into observable size, and re-emits the energy as real, observable photons radiated in all directions at light speed, establishing and continuously replenishing its associated EM fields and potentials and their energy.
The common electrical engineering and classical electrodynamics implicitly assume that every EM field, EM potential, and joule of EM energy in the universe has been and is freely created out of nothing at all, by the associated source charges. It assumes that because it assumes NO ENERGY INPUT to the source charge at all. It assumes an inert vacuum -- falsified for decades in particle physics -- and a flat spacetime -- falsified since 1916 by general relativity. In quantum field theory, the charge is actually a dipolarity, since the bare infinite charge in the middle is surrounded by an infinite charge of virtual particles (of opposite charge) by the well known polarization of the vacuum by the observable charge. The external observes "sees" the difference, which is finite and the common textbook value of that "observable charge".
Rigorously that dipolarity of the source charge must obey the broken symmetry of opposite charges. That rigorously means that the special QFT dipolarity of the source charge continuously absorbs virtual energy from the vacuum, converts it to observable energy, and re-emits that energy. Again, Lee and Yang received a Nobel Prize in 1957 for their strong prediction in 56 and 57 of broken symmetry. Wu and her colleagues experimentally proved it in 1957, and so profound was that revolution in physics that the Nobel Committee awarded the Nobel Prize to Lee and Yang the very same year, in Dec. 1957.
So there is a great deal more in physics than has made it into that more than a century old electrical engineering model! It would be nice if broken symmetry in the nearly half century since that Nobel Prize to Lee and Yang, had migrated across the university campus from the physics department to the electrical engineering department, and gotten them to change their model and their textbooks to include the extraction of EM energy from the vacuum by the source charge, so that they could quit erroneously assuming that all EM fields and potentials are freely created from nothing at all.
Subject: COP vs Efficiency