A voltage stabilizer cannot provide more electricity than it receives at the input. This is the well-known law of conservation of energy. However, using a voltage stabilizer actually saves energy. And that's why. It's all about the efficiency of the consumers themselves. All electrical appliances are designed for use at normal current values. And it is at normal voltage that they have maximum efficiency (efficiency factor). With reduced or increased voltage, efficiency will decrease. This means more energy will be spent on lighting, heating, cooling and other types of work.
Let's look at specific examples.
Lighting. Everyone has observed that at low voltage, incandescent light bulbs glow very dimly. At a voltage of 180 Volts, the brightness of the lamp drops by half. This means that to illuminate the room you will need to turn on another lamp. In this case, energy, of course, is not lost, just most of it will go into heat generation. Using a stabilizer in this case provides real savings in electricity for lighting.
Fridge. When the voltage is low, the refrigerator does not work well, the compressor often starts, and does not turn it off for a long time. At very low voltage, it can often turn off without gaining “cold.” When the voltage is low, the compressor motor does not work well. As a result, the refrigerant pressure is not sufficient for efficient heat transfer. The voltage drops by 20%, and the compressor is forced to work twice as long. Thus, significantly increasing energy consumption from the network. Using a stabilizer in this case provides real savings in energy for cooling.
Kettle. It would seem, what is the problem here? But the kettle doesn’t like low voltage either. Although no. In principle, “everything is fine” for the teapot. We don’t like it when the water in the kettle takes half an hour to heat up or doesn’t heat up to the required temperature at all. Is there any power loss here? Of course not. It’s just that when heating slowly, the kettle has time to transfer more heat to the environment. That is, the kettle also works as a heat radiator. And you pay for it. Using a stabilizer in this case provides real savings in heating energy.
Vibration pump. Increased voltage will cause the magnet armature to hit the pump housing with greater force. Yes, the sound of the pump will become louder, but will it pump more water? No, the operating frequency will be the same, and the piston volume will not increase either. In this case, the efficiency of the pump will decrease. With reduced voltage, the pump will work less efficiently, and performance may drop (even to a complete stop). With a reduced voltage, the current in the windings of the pump electromagnet will increase, which will lead to its overheating. Using a stabilizer in this case provides real savings in electricity for pumping water.
So. Let us summarize the general conclusions.
Can a voltage stabilizer save electricity?
From a physics point of view, a stabilizer cannot save energy consumption. And so it is.
But from the point of view of the need to perform useful work, the use of a voltage stabilizer can save the energy required to perform a unit of work. So in this case, the voltage stabilizer leads to a reduction in losses of powered electrical devices.
What is more important for us is how much energy will be used to produce cold, and not how much energy the entire refrigerator will consume. If, as a result, less electricity was used to produce a unit of cold, then the voltage stabilizer can save electricity.