Power Saver Plugs

Some more examples of power saving plugs being sold on Amazon here

Power saver plugs claim to reduce your household electricity use by simply plugging the device into a socket. The description of how these devices operate is usually vague and they often use nonsense terms like ‘straightening the current’, or ‘cleaning the dirty voltage’. Sometimes they may also mention ‘balancing current’ and using capacitors. Like all good scams, there is a grain of truth behind this. The principle they appear to be based on is Power Factor Correction. Power factor correction is a genuine method of reducing electricity bills for commercial and industrial consumers. Unfortunately, these scam devices will not make any savings on your household electricity bill.

Domestic Electricity Bills

Power factor correction will never reduce household electricity bills. Domestic customers are only ever charged for Real Power, measured in kW or kilowatts. The power factor of the load does not affect your electricity bill and using a power factor correction device will not make any difference to the amount of electricity you are charged for.

Commercial Electricity Bills

Commercial and industrial customers are charged differently for electricity than domestic users. Businesses can incur extra charges if their equipment causes the voltage and current to fall out of sync (out of phase). Many types of industrial machinery, such as motors, compressors and transformers, naturally cause the current to lag behind the voltage. By adding capacitors, the current and voltage can be brought back into better alignment. This process, known as Power Factor Correction, helps reduce those extra commercial charges. Power factor correction equipment must be correctly sized so that it matches the electrical loads on the system. This article by the IET gives a great technical explanation of Power Factor Correction.

Safety Concerns

Electrical Safety First, the electrical safety charity, commissioned a series of independent electrical safety and performance tests on a number of these energy saving devices. The investigation revealed serious safety hazards for all the products tested. You can download the full report from the Electrical Safety First website.

If you’re responsible for electrical safety at work, our PAT testing courses cover safe inspection, testing, and how to spot dangerous products.

Voltage Optimisation

Plug-in power saver devices should not be confused with voltage optimisation. Voltage optimisation is a genuine method of regulating the supply voltage and is normally installed between the electricity meter and the consumer unit by a qualified electrician. It is not achieved by plugging a small device into a socket.

Voltage optimisation may offer savings in some situations, particularly where equipment is sensitive to supply voltage or where there are suitable inductive loads such as motors, pumps and fans. However, it should be properly assessed before installation and should not be assumed to reduce every electricity bill.

Genuine Ways to Save Energy

Although plug-in power saver devices will not reduce your electricity bill, there are practical ways to cut energy use around the home. Simple changes, such as avoiding overfilling the kettle, switching off appliances on standby, using pans with lids, and replacing older lamps with LED bulbs, can all make a measurable difference.

We have put together a separate guide with real examples and cost calculations here: Energy Saving Tips and Calculations.