A good way to lower the grid voltage for economy purposes

[Michaelp]

I have seen few cases where the owner of a factory uses transformer after the grid to lower the voltage, from 240 to 220v as a way to lower the consumption and at the end to save money.
I was wondering if an inverter will do much better the job instead of a simple transformer as you can keep or change the settings any time you would want to.
For example,one case is a 3phase 100Amps transformer and transform the voltage from 240v to 220v.If lets say in the future the factory expand his land to the next plot he will have a bigger voltage drop so he will have to raise the voltage to 230v so to meet the standards.He will need to change the transformer or remove it.
With an inverter it should be simpler just a different setting on the output voltage.
Any thoughts ?

 

[DPG]

It would need to be a huge inverter.

 

[PEG]

It would need to be a huge inverter.

Yeah...but it would be beautiful!

 

[Moley]

As beautiful as this one?

 

[DPG]

Where's that one, and what is it feeding?

 

[Moley]

It's at BritNed, the Uk / Netherlands interconnector. If I remember right that's the Uk side.

 

[CherylBlasko]

Mostly in the commercial area, people actually need this to save money on the utility bill. In the signal transmitting station, an inverter is mostly used.

 

[GeorgeCooke]

Lowering the voltage does not in general save money. Heating loads go down but need to run longer. Modern lighting loads use switch mode techniques and are constant watts. Motor loads could stall but most likely draw more current to maintain torque.

The US uses half our voltage but their energy consumption is way above ours.

 

[Simon47]

Agreed, and there have been discussions on and off in various forums - usually in relation to the DNOs doing it for short term demand management. Note that, as I read it, the customer savings they talk about are not through energy saving - but through deferring the need for network upgrades by managing peaks in demand.
There is no "magic box" that will cut power consumption - as suggested, if (eg) a certain amount of heat is needed, then lowering the voltage to a heater will simply result in that heater running running at a higher duty cycle.
However, if that heater is on full time AND whatever it is doing can be achieved with less heat, then adding a control to regulate the heater to provide what is needed and not a watt more will give a saving.
Similarly, quite a few motor driven things can be run more efficiently. For example, it's quite common to have DOL pumps where the flow rate is set by a throttling valve - inefficient by design, but cheap to implement (and most plumbers can understand the concept of a valve that's only part open to control the flow. Replacing these with an inverter driven pump, and setting the flow rate by setting the pump speed will also give a power saving - but costs for the inverter drive (and installation), and needs someone with more skills than most plumbers to set the drive correctly.

 

[Michaelp]

Yes , that it should be common sense. Nobody said is a free energy kind of thing.Is the Ohms Law.Lower the voltage lower the W lower the consumption.If the work needed is depend on exact energy for exact time it may not be useful for you as it will need more time to cover the exact energy needed so you draw the same amount of power without any "savings".