Go4Green Energy Smart ... not so smart.

The advertising for the Go4Green Energy Smart sounded great: “Fit & Forget – simply plug into any power point close to everyday appliances and switch on … designed and proven to reduce kWh usage and electricity costs by up to 10% and more …Tried & Tested – fully certified and independently tested ECO product.”

But it wasn’t true … and the device was electrically dangerous, too.

As a result of our investigations, Go4Green Energy Smart has been banned from sale and use in New Zealand.

Even though it claimed to have safety approvals, Go4Green wasn’t electrically safe. It used a small internal capacitor to attempt to save power, which meant it stored electricity. If you removed it from a live wall socket, it would have 230 volts stored up and the pins would still be live. Both here and in Australia several people have had an electric shock from touching the pins accidentally.

The device has just been banned by Energy Safety. So it can no longer legally be used by anyone who’s bought one.

No power savings

We bought our sample from www.thedeal.co.nz and tested it in a typical household setting.We set up a simulated household circuit that allowed us to run Go4Green on a heat pump, fridge, washing machine, clothes dryer, fan heater, compact fluorescent lamp, microwave oven, and DVD player (in separate test runs, of course).

We gave it the best possible chance to demonstrate any savings by plugging it in close to all these household appliances.

Except on the fridge, the Go4Green saved no energy at all – and even worse, it added a little to the energy bill. In a typical household, any savings for one appliance would be cancelled out by the losses from others.

Although our measurements show a possible small saving from the fridge, this won’t show up on your power bill, because electricity meters cannot measure the change. See below for an explanation of this.

We say

• If you have one of these devices, stop using it immediately. Remove it carefully from the wall. Avoid touching the pins, and carefully put it back in its box, or a plastic container. The capacitor will self-discharge in a few days.
• Because it’s a faulty product, you can claim a full refund from the seller – so get on to it now.

How it’s supposed to work

The device claims to work in three ways (key points are bolded by us).

"What our product does in essence is improves Power Factor and corrects Harmonics. Residential consumers WILL NOT save money by a simple decrease of reactive power as residential consumers do not get charged for reactive power BUT Power Factor lag or lead (lag being the most prevalent in inductive appliances which include electric motors) results in I2R losses in the cables feeding the individual appliances which leads to high power consumption due to the losses. Whilst it is correct to assume the energy kWh meters do not record out of phase reactive power they do record the sum of I2R losses in the cables feeding the individual appliances, therefore correcting the power factor saves energy and reduces power costs to the consumer."

Our analysis: Power factor “improvement”. We’re not sure if you can improve a power factor, but it’s possible to correct for it. This is regular practice for large industrial electricity users.

Electrical motors, which create an inductive load, tend to draw the current they use out of phase to the normal AC (alternating current) sine wave. The greater the difference in phase from the AC sine wave, the lower the “power factor” that results. Large industrial users must monitor their power factors, and correct them, so they pay for the true amount of energy used.

This is not the case for households where most of the load is resistive – for example, hot water, heating and cooking, all of which have a power factor of 1 (or 100%), meaning the sine waves align. So power factor correction isn’t required. The Go4Green does correct the power factor to a very small degree, on some motor-driven appliances in some operating modes. But you’d be lucky to pick the right appliance to control by plugging a Go4Green into a randomly selected wall socket. And it does not create any saving on your electricity bill, because your meter only reads the “in-phase” component of electricity use.

Our analysis: Harmonic “correction”. What is a “correct” harmonic? Harmonics are neither correct nor incorrect. Our test electrical engineer says: “In theory, adding a capacitor across the mains supply can influence harmonic levels, but this will not be in a controllable or predictable way. Any influence on a whole house will vary depending on how many appliances of what type are running at the time, as well as the unknown and variable impedance of the mains supply to the house”.

Our measurements showed some very small reduction in harmonic current in some situations, and some very small increases in others. Overall, the effect of changes in harmonic currents across our “household”of appliances was insignificant.

Our analysis: I2R losses.This appears to refer to I²R losses, or the square of the current multiplied by the resistance. Domestic electricity meters do not record the sum of I²R losses; they record the product of the in-phase current component and the applied voltage. Neither will be affected by the Go4Green device. Our engineer concluded: “the third claim appears to be a collection of statements from electrical engineering textbooks, taken out of context and without any understanding of electrical theory".

How your meter reads electricity use

Household electricity meters read electricity use in a relatively simple way. They measure the in-phase part of the alternating current and calculate the use in kWh.

Most of the electrical appliances in a typical household create what is called a resistive load. Heaters, including the hot-water cylinder, electric stoves, electric jugs, toasters, electric frypans, slow cookers, electric blankets and standard light bulbs are all resistive-load devices. Hot-water heating alone can make up 30% of a household power bill. Resistive load has a power factor of 1, which means the electricity is used 100% in-phase and the meter correctly measures every unit used.

Electric motors such as those used in washing machines and fridges, as well as some standby devices and compact fluorescent light bulbs, create an active load which moves the alternating current cycle out of phase with the voltage at the point of use. A standard electricity meter will record only the “in-phase” current that a motor or other device actually draws from the national grid.

For household purposes, the amount of use that is not captured is usually so small it’s not worth trying to correct for it.

However, large industrial users must work out the “power factor” that applies to their large motors and apply “power factor correction” or else pay a “correction fee”.

More information

Power Factor Fraud: http://sound.westhost.com/lamps/power-savers.html
 

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