Testing the Rossi E-Cat

by Brian Dunning
March 3, 2026

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Today we’re going to have a look at a cold fusion device (also called LENR for low energy nuclear reaction) that has been around far longer than most, and which promises to solve the world’s energy problems with clean, limitless, and practically free power. It’s called the E-Cat, for Energy Catalyzer, and it’s the brainchild of Italian Andrea Rossi. Cold fusion has a deservedly bad rap, and is widely considered implausible. So what then is the E-Cat really doing, and most importantly, does it really work?

Physically, the E‑Cat couldn’t be simpler. It’s a small cylindrical reaction chamber containing a metal structure and a powder mixture including nickel and lithium compounds. Water flows in one end, is heated as it passes around this chamber, and flows out the other end; the claimed energy output is inferred by comparing inlet and outlet temperatures and flow rate. Rossi attributes this heating to “cold fusion”: a low‑temperature nuclear reaction in which hydrogen, plus a proprietary catalyst he refuses to disclose, allegedly enables nickel nuclei to fuse with hydrogen and transmute into copper while releasing heat. The hot water or steam exiting the machine can then be used to turn turbines and generate virtually limitless electrical power. The whole machine is a convenient tabletop size; about the size of a microwave oven.

Importantly, the E-Cat has to be plugged into the wall. This provides power to its water pump, its control electronics, and a resistive heating element inside the chamber. That right there might suggest a red flag: If the machine allegedly uses cold fusion to heat the water, why does it need an electric heater? That, says Rossi, is merely to get the reaction started. Once it’s going, the power to the heating element can be turned off. Remember this point, as it will become more important later on.

Rossi began filing for patents on the E-Cat back in 2008, and has been giving public demonstrations since 2010. By 2011, the press was almost entirely negative, with every article pointing out that its claimed mechanisms either violated known physics or were meaningless word salads. Rossi’s demonstrations nearly always did succeed, apparently; with the measured energy output far exceeding the power it had consumed to get started. Significantly, however, Rossi always maintained absolute control over the demonstration conditions. He has never allowed a unit to be independently tested, nor would he allow certain closeup inspections during the demonstrations. This lack of transparency deeply divided the alternative energy community. However, eventually some seventeen legitimate, credentialed scientists did sign on and endorse — if not the claimed mechanism — the apparent fact that the E-Cat did indeed produce substantially more energy than it consumed.

Today, the E-Cat is back in the news. Rossi has long been promising to make the devices available for sale, and according to reports, he has shipped his first units as of December 2025. No word yet on whether anybody has gotten one to work.

The majority of the science community has always ignored the E-Cat, however. First, because Rossi’s claimed mechanisms violate known physics; second, because it has never been independently shown to work as advertised; and third, because Rossi’s own background is highly dubious. He’s a serial inventor of similar devices for which he made false claims and has been imprisoned twice, in 1995 and 2000, for convictions connected to these machines, including fraud, money laundering, dumping toxic waste, and so on.

Accordingly, the list of scientifically false claims he makes about the E-Cat is a long one. Here are just a few:

• Rossi says the temperature inside his reaction chamber reaches 8,111°C, yet the highest melting point of any material known to science, hafnium carbide, is only 3,982°C. But this small tabletop box manages to withstand it just fine, without melting.
  
  
• When nickel fuses with hydrogen to form copper — Rossi’s central claim — high-energy gamma rays in the MeV (mega-electron volt) range are emitted. These are extremely dangerous and would prove fatal to everyone in the room. Shielding of some tens of centimeters thick of lead, or meters of concrete, would be needed if people were to be near the E-Cat. However, the device obviously has no shielding of any kind, and yet everyone in the room strolls about observing without any consequence. It would be trivial to detect radiation from the E-Cat with a Geiger counter, but none is detected at all.
  
  
• The claimed mechanism for this fusion is that a negative hydrogen ion takes the place of an electron in one of nickel’s outer shells. Anyone who knows basic chemistry and physics knows that this is complete nonsense. Nuclei are not located in electron shell positions. They cannot be: the Coulomb repulsion between positively charged nuclei (the Coulomb barrier) prevents them from ever approaching that closely under such conditions.

Finally, Rossi also cites “zero point energy,” for decades a favorite phrase used by pseudoscientists and free energy believers. Hearing someone talk about “using” or “extracting” zero point energy is always a cause for concern. This means the same thing as pouring water out of an empty bucket, or taking an elevator down from the ground floor. When all the extractable energy is removed from a system, it is left in its ground state, or its zero point energy. A system still has energy in that state, but no lower‑energy state exists to drop into.

Consider the analogy of a brick sitting on the ground. That brick is sitting at its lowest possible height — its “zero point height” if you will. One might hear that phrase and say “Ah! So it’s at some height; that’s the height I’m going to drop it from.” But it can’t drop, it’s already on the ground. There is nothing lower. In the same way, a system’s zero point energy is its lowest possible energy state; that’s literally how the term is defined. You can no more extract energy from a system that is already at its minimum than you can drop a brick that’s already on the ground.

Why this gets confusing is because it involves quantum mechanics. At the quantum level, no particle has both a defined location and momentum; if either is established, the other is changed. This is the core of Heisenberg’s uncertainty principle, and it is a fundamental law of nature. This constant flux is why the minimum energy is not zero — and not even Andrea Rossi can violate fundamental laws of nature.

So we know for a fact that all the explanations for the E-Cat are false. Rossi is either lying or is profoundly wrong about what the E-Cat does. The most likely explanation is that he’s being deliberately deceptive in order to generate sales.

And deception is what brings us to the fundamental reason that so many have been fooled by Rossi’s demonstrations, which is that the wrong kind of experts have been present. Chemists and physicists and electrical engineers can all look at the machine and can all observe the measurements, and they can all be surprised to see that the E-Cat’s energy output exceeds the input. They can all conclude that something extraordinary must be going on, and can all sign statements attesting to that — as seventeen of them did. The problem is that’s where their expertise ends.

What’s been missing — at least, until the Australian Skeptics got in on it — were experts skilled in the arts of deception. Not people scratching their heads and going over nuclear equations, but people familiar with the tricks used by conmen to fool their marks. With Rossi’s multiple convictions for deceptive schemes and his total lack of relevant experience or credentials in physics, isn’t the most likely explanation for the E-Cat that it’s another of his deceptions, and not a physics breakthrough that has confounded all the world’s fusion experts?

In 2011, an intrigued investor in the E-Cat approached Australian philanthropist Dick Smith about financing a license to resell the device. But it turns out Dick Smith is a fellow of the Committee for Skeptical Inquiry — a descendant of CSICOP — and does his homework. He took the matter to the Australian Skeptics, specifically to Ian Bryce, an engineer and physicist. What Bryce found was a perfectly elegant probable solution to the excess energy production, and which he published in Skeptical Inquirer magazine in 2019.

The tipoff was a blue wiring box packed with a rat’s nest of tangled wires, in contrast to the rest of the E-Cat’s tidy construction. To the skeptical investigator, this suggests an effort to hide something. Bryce found that the grounding wire could be quickly and easily reconnected to a different pin, sending the electrical outlet’s full current to the device’s heating elements, and then just as quickly and easily switched back after the demonstration. During the demonstration, if anyone tried to use a clamp meter to measure the current the machine was drawing from the wall, Rossi (who never left the computer keyboard while his demonstrations were running) could simply deactivate those heating elements, returning the current draw to normal; then once the clamp meter was removed, he’d switch them back on before the drop in output energy was noticed. It is a simple trick that fools the scientist who is looking at other things, but it does not fool someone looking instead for deception.

Of course it hasn’t ever been possible to prove that’s what Rossi was doing, because he has always consistently refused to allow independent examinations of his equipment. But Bryce went back over the data from all of Rossi’s demonstrations from 2010 through 2011 and found the results lined up perfectly with this hypothesis. Smith offered Rossi one million dollars to simply run a demonstration while someone monitored a clamp meter on the grounding wire. If Rossi was genuine, this would have been the easiest money in the world — but he refused.

To read about the current state of the E-Cat, you’d think it’s about to take over the world. All sorts of customers, license holders, distributors, and pending deliveries are claimed by Rossi; but not one with a verifiable identity. Articles about either the man or the machine are peppered with words like scam and fraud — characterizations that certainly appear to be consistent with the E-Cat itself. With so much focus on renewable energy these days, one wonders why Rossi doesn’t simply open a business selling legit lithium-ion batteries or something. There is money to be made in adding value to the world; much less so when you seek only to swindle it.

By Brian Dunning
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