My dad just bought a device that claims to reduce electricity consumption in the house. It is called a Spike Buster. It is just a small box with an LED that you connect to any socket in the house. It claims to stabilize the voltage of the electricity and as a result the consumption is reduced.

This looks very suspicious to me. It doesn't makes sense to me. Is there any reliable info on these devices that I can show to my dad?


3 Answers 3


Definite scam!

Save up to 50% on your electric bill? Because of a device plugged into any outlet?

Uh, no.

Here's PG&E with a warning about "black box" energy savers: Before You Buy a Black Box

In the last few years I've noticed a huge "surge" :) in scam "electricity saver" products. Some are PFC capacitors, some are plans for "free energy" devices, some are ripoffs involving solar panels. Yours is just one of many, although this is the first time I've seen a claim that a surge protector can affect your KWH meter. And if it's actually a voltage regulator, then it needs to be wired into your fusebox panel. A regulator needs a series connection and cannot work by being plugged into an outlet.

Similar topic:

The old standby scam is to sell capacitors to homeowners, claiming that the AC motors in their appliances need correct power-factor. The scammers can get away with this because PFC power-factor correcting does actually save energy. Unfortunately the saved energy was all in the utility company power lines, not inside the home. The electric company will love you if you spend hundreds of bucks on a PFC capacitor. Their power lines run slightly cooler, and their generators use slightly less fuel. The higher current all remains between the capacitor and your various motors, so electric company is happy. But the scam part relies on customer ignorance: your KWH meter cannot detect the change. That's part of its design. Power-factor correction has zero effect on your KWH meter, so it won't actually save you a dime.

If you buy a fake "Power Saver," probably you'll see your electric bill actually go down. This is an interesting psychological effect: spending that much money makes you become waste-conscious about the electric utility. You'll start turning off lights, taking shorter showers, running dishwashers only when full. Doing all sorts of things to help reduce the bills. When it actually works, should we give credit to the magic scam box? Send testimonials to the advertisers? Instead try installing the device in someone elses' home, then don't tell them about it. Will it still work? Better yet, have a 3rd party do it without telling anyone which house has the device. To stop everyone from unconsciously helping it along, the only fair test is a double-blind experiment.

Well, actually the fairest test is to use high-precision real-wattage recorder to measure home energy consumption with the device attached and with it removed. We all have one of these: the electric meter outside the house. Run your electric clothes dryer, hook up the "power saver" device, then count the rotations of the meter disk for exactly one minute. Then unplug the device and count them for another minute. Repeat a few times. Can you see any difference? If so, is it large enough to justify the purchase price of the device?

One "power saver" does actually work. These are the NASA "Nola" devices used to control induction motors (for example, refrigerator motor). They remain controversial because they're mostly used industrially, and the energy savings is probably too small for any homeowner to justify buying the expensive controller. If someone tries to sell you one, they're probably lying about the expected amount of energy savings.

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  • Actually, I've heard this is a similar problem to do with the CFL bulbs. Because they have a high power factor, they put more strain onto the system than the old incandescent bulbs did. But because of the way you are billed, you get lower electricity bills. See this article. greenhomeauthority.com/drawbacks-cfl-vs-led
    – Kibbee
    Nov 28, 2012 at 13:45
  • Kibbe - here's an article on CFL bulbs and power factor from Sylvania: ceolas.net/Docs/Sylvania_on_CFL_Power_Factor.pdf
    – Mark
    Nov 29, 2012 at 0:32
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    I guess I can't touch the return key in a comment... Anyway, they don't put more strain on the electric system , they reduce both billed power use and generated power. The low PF in some bulbs means that the reduction in generation is not as large as the reduction in billed use, but they still save electric power.
    – Mark
    Nov 29, 2012 at 0:35
  • youtube.com/watch?v=J86QK0Njfv4
    – ventsyv
    Oct 27, 2021 at 17:02

Maurio Grassi at Silicon Chip took one of these apart

(Electricity savings box circuit diagram)

As @William Beaty guessed, it's basically just a big capacitor to correct the power-factor; since you are not billed on your power-factor, this will save you absolutely no money.

"Power Factor" and devices that claim to save energy by fixing it explains and debunks these power-factor scams.

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    Plus correcting the power factor requires you to actually know what you are trying to correct. If your load is inductive than adding capacitance will make power factor better but if not then adding capacitance will make power factor worse. Jan 11, 2018 at 19:20
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    Not that it affects the validity of the answer overall but I'd say when that schematic has been produced the mu characters have been dropped and the values should be 6.2μF and 100μF. A 6.2F mains rated capacitor would be huge and expensive.
    – PeterJ
    Jan 28, 2018 at 2:42
  • @PeterGreen, most unbalanced loads are inductive: transformers in power supplies, coils in motors, etc.
    – Mark
    Jul 16, 2020 at 3:21
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    I'd imagine most of the PF issues in domestic properties nowadays would be harmonic currents from switchmode power supplies rather than the traditional inductive/capacitive issues. The remaining AC motors would likely be behind thermostats/timers/controls. Jul 16, 2020 at 3:46
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    This component values in this schematic make very little sense... Bad source.
    – Lundin
    Mar 24, 2023 at 15:11

The name suggests that this is some kind of surge protector which is designed to protect electrical and electronic equipment from spikes in mains voltage; it may also protect against some lightning strikes. Looking at the following commercial links here and here, that is exactly what is being offered. There is no claim of energy saving, just protection from spikes.

There are commercial claims of energy saving, such as here and here, which seem to be more general voltage regulators. In theory, if there is persistent over-voltage in the supply, a voltage regulator will reduce consumption since power is voltage times current and for a fixed resistance both will rise. In practice I suspect under-voltage is more common and so a voltage regulator will tend to increase energy consumption, though only to the level it would be if the supply was at specification plus any consumption by the regulator itself.

  • I suppose it varies for each house (and each circuit). In my house during renovations a few months ago I hooked my meter up to various outlets and saw voltages ranging from 117 VAC to 129 VAC. I also saw a few that showed 17-19 VAC or 50-55 VAC. Replacing wiring, switches, lighting fixtures, and outlets resulted in ranges much closer to 120-125 VAC. Jul 28, 2011 at 20:13
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    the one that claims energy saving is the one my dad has. exactly the same gadget Jul 28, 2011 at 20:33
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    Surge protectors need to be between the main and the devices. Plugging it in any socket won’t do anything. Furthermore, the description of the alleged functionality doesn’t match. Jul 28, 2011 at 20:38

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