In This Town, We Still Obey The Laws Of Thermodynamics
It has been five years since we posted the report on the Perepiteia Generator, a device that inventor Thane Heins, is careful not to call a perpetual motion machine (except that it would be if it worked as described, but it doesn’t, which means he’s accidentally telling the truth). Since then, the original article has gathered a couple of comments which perhaps deserve a reply. Also, we’ve been on Heins’s mailing list ever since, meaning that at intervals we receive a blast of self-promotion from him, usually accompanied by documents purporting to show positive results for his experiments, and — fascinatingly — email exchanges he has had with other people, which Heins apparently interprets as endorsements (I think — sometimes it’s difficult to discern the purported significance of the attachments). In addition, in 2010 Seanna and I were interviewed for a CBC documentary series on maverick inventors (or if you prefer: crackpots), which is the first (and likely only ever) time we have been interviewed on the same radio program as Steve Novella. All of which culminated in a presentation to Ottawa Skeptics this last spring.
So, What’s Up With Thane Heins?
Some good stuff, some not so good (ie. for Thane Heins). On the one hand, he now claims a partnership with e-bike maker HERO, and is working on integrating his Perepiteia device (re-branded as ReGenX, and with a shiny new theory about how it works) into an e-bike. On the other hand, in 2010 the University of Ottawa evicted Heins from their lab space, and based on the videos at his Youtube channel, it looks like he’s back to working out of his basement. As a side-line, Heins has also discovered chemtrails in the sky over Ottawa and environs. Yes, those chemtrails.
Well, does it work, or what?
Heins’ claims regarding his invention are a bit roundabout. For example, from a 2011 press release:
An independent test of a Heins’ innovation conducted at the University of Ottawa required just forty percent (40%) of normal energy input to double generator output (200%).
Note what it doesn’t say: that Perepiteia produces more power than it consumes; only that it is possible to increase the output power of his device while decreasing the input power. That in itself may sound great until you realize that it is satisfied by, for example (using numbers that are made up — but typical of his reported results): a machine that produces 1 watt of output power with 100 watts of input, but under different conditions, produces 2 watts of output while consuming 40 watts. In other words, the claim, while sounding impressive, tells us nothing about whether Heins’ invention represents fundamentally new physics, or even a useful improvement in generator efficiency (an increase of efficiency from a mere 1% to a only-slightly-less-mere 5% is….distinctly unimpressive).
By the way: the headline on that press release? About the ”patented energy breakthrough”? While a search of Canadian, American and international patent databases turns up several patent applications from Thane Heins (for ReGenX and other inventions), none have ever been issued, and in fact, all are now expired. As far as I can determine, Heins has no granted patents to his name.
I don’t know which set of results Heins bases the above claim on, but here is a typical set of results, extracted from one of his emails:
|100 Ohm Load||121||2.13||3455|
The first line of the table, labelled ”No Load” represents the case where nothing is connected to the generator output. In this condition, the entire 129 watts input to the motor is going to losses in the wiring, in the magnetic cores, in bearing friction. The second line of the table represents the case where he has connected a 100 ohm load resistor across the output. Now getting 2.13 watts out is not very impressive, but the interesting part here is that the motor input power, while still much larger than the output, has dropped by 8 watts! Moreover, the shaft speed has increased from 3440 RPM to 3455 RPM — also counter-intuitive, as one would normally expect a generator to slow down under load.
This is the core of Heins’ claims about ”regenerative acceleration” — that an electric vehicle equipped with a ReGenX device can recharge its batteries while accelerating. He uses the term ”regenerative acceleration” in contrast to the regenerative braking performed by hybrid and electric vehicles, in which the electric motor is run as a generator, converting some of the kinetic energy from the wheels back into electricity. Heins claims he can also perform that trick while the vehicle is speeding up.
Is it free energy?
Well, Heins thinks it is. His reasoning goes: the no-load test tells us the system losses. So if the input power drops under load, we also get some output power, the difference must be coming from….wherever it is that free energy comes from. In this case, we’re getting:
129-121+2.13=10.13 watts of free energy
Using 121 watts to create 10 watts of free energy is obviously not going to solve any energy crisis — the overall efficiency of the ReGenX is still less than 2%, where conventional generators are typically 90% efficient. But to be making any free energy at all would be remarkable — if this represents proof-of-concept, then surely all we have to do is tinker with things, scale it up a bit, and we can achieve over 100% efficiency, right?
But note the assumption Heins is making: that system losses under load are the same as no-load losses. There is no reason to accept this, and good reason to reject it. To understand why this is, it’s necessary to take a close look at what’s going on in the ReGenX, and to do that, we need to understand a little basic generator theory.
Generator Theory 101
The diagrams below represent a generator coil such as is found in the ReGenX: a length of wire wound around a core made of some iron alloy, with the ends brought out to the load (represented here by a light bulb), with a moving magnet passing by the end of the core. Let’s consider in detail what happens as the magnet approaches, passes, and recedes from the core. In the following discussion, keep in mind we’re considering the ideal case — the kind of thing presented in an introductory course.
First, you need to know two basic rules about electromagnetism:
- Electricity makes magnetism.
- (Changing) magnetism makes electricity.
As the magnet is approaching (see Diagram #1), its field begins to enter the iron core (red arrow), ie. the magnetic flux in the core starts increasing. The increasing magnetic flux induces a voltage in the coil (see Rule #2), causing current to flow through the load. However, the flowing current induces its own magnetic field (see Rule #1) in the core (blue arrow). According to Lenz’s Law, the induced field will oppose the increase in the applied field, ie. it will point in the opposite direction. This means that it repels the approaching magnet.
In Diagram #2 the magnet has passed and is now receding from the core. As it does so, the magnet’s field in the core will be decreasing, which again induces a voltage in the coil, only now in the opposite direction. Since the coil current now flows in the opposite direction, the induced field also points in the opposite direction (again, this is in agreement with Lenz’s Law, according to which the induced field will now try to maintain the field in the core). This means that it attracts the receding magnet.
The alternating repulsion and attraction, always opposing the motion of the magnet, puts mechanical resistance on the motor that is driving the magnet, thus slowing down its rotation, and causing it to draw more power from the supply. This is the normal, expected behaviour. Note that Lenz’s Law figures prominently in the physics of the situation — in fact, it’s easy to show that Lenz’s Law is equivalent to conservation of energy for magnetic devices. If you can fool Mr. Lenz, you have a free energy device. Thane Heins knows this, which is why he claims to have partially overcome Lenz’s Law, and why he makes much of the generator speed-up observed in his experiments. In fact, he claims that his ReGenX machine reverses the alternating repulsive-attractive behaviour of the interaction between the magnet and the core.
The Core of the Matter
The discussion in previous section assumes ideal behaviour. Among the effects neglected is core loss due to hysteresis and eddy currents. Hysteresis is the tendency of the core to retain the applied magnetic field after the field is removed (in other words: to become a permanent magnet) and is a characteristic of the core material. Eddy currents are electrical currents induced in the metal body of the core, rather than in the coil. Both of these phenomena consume energy, generating waste heat in the core. And of course the power wasted in the core is felt by the prime mover, every bit as much as power delivered to the load is. We have been building motors and generators for over a century, and lot of research has gone into developing materials and construction methods to minimize these loss mechanisms. In modern commercially-manufactured machines designed by professionals they are negligible.
Thane Heins, while a competent enough handyman, is not a professional. We don’t know what his generator coils are wound on, though it may very well be the same mild steel that the structure of the apparatus itself is built from. In any case, they are probably lossy — losses which are incurred whether or not there is an external load connected across the output. In other words: Heins’s no load condition is already significantly loaded by core loss.
So why does the the generator speed up when a load is connected? Refer again to the diagrams: the induced field, created by the load current, opposes, and thus reduces the applied field, therefore reducing the losses. Paradoxically, Heins’s loaded condition is actually less loaded than his no-load condition.
But why does it draw less power when it’s running faster?
One last detail: a lot of people (such as one of the commenters on the previous post) are under the impression that, contrary to the observed behaviour of ReGenX, the driving motor should draw more power as it runs faster, not less. Certainly it seems intuitive. Explaining why this is false would require several hours of lecture on basic electric motor theory but nonetheless the opposite is true (and the reasons are taught in every introductory undergraduate course on the subject). The diagrams below plot torque (blue curves) and input current (orange curves) vs. speed for two common types of electric motor, both of which have been used by Heins. Note that, in both cases, the current falls as speed increases, over the entire operating range of the motor.
In ReGenX, Thane Heins has built a fantastically inefficient generator, and then runs it in a way that makes it just slightly less inefficient. The ReGenX device does not represent free energy, or any other novel physical phenomenon: merely bad magnetics — and lot of self-promotion.