That is a completely different thing, before we got the HF fluorescent fitting, the old wire wound ballast was very voltage dependent, I did some experiments with an auto transformer, and that was what the voltage optimiser was, my was on a 58 watt 110 volt fluorescent fitting, and auto transformer was 110 - 0 - 127 volts. So supply in could be either 0 - 110 or 0 - 127 output should be 237 volts.
I found swapping voltage could change current used from 0.5 amp to 0.8 amp, so a string of 25 fluorescent fittings, 12.5 amps to 20 amps the latter was tripping the 16 amp overload. So on the supply to fluorescent lights with wire wound ballasts, the voltage optimiser worked well.
But the HF ballast changed all that, a 58 watt fluorescent lamp was actually using more like 54 watt, and it also increased the light output, and time the tube lasted, so with a HF ballast the fluorescent lamp was on par with the LED, but cheaper to maintain. And the voltage optimiser was no longer any use.
I'm still trying to work out how ebee is going to convert 220000V dc down to whatever voltage his home device requires,
It does seem that is what is done to import or export to France, the power across the channel is DC.
I'm sure Ebee wasn't taken in by this ad, he was simply pointing out that it included some true points, to back up their basic lies about the value of the device.
That was also what I was thinking, I know this is an extreme case, but most of the silly claims have some element of truth.
I have heard it said many times, an electric heater is 100% efficient, it does not matter if a fan heater, a panel heater, or an oil filled radiator they are all 100% efficient, but this is not true.
If one wants a room at 22°C at 6 pm, and it is at 16°C at 5 pm, then likely the fan heater needs to be switched on at 5:45 pm, the panel heater at 5:30 pm, and the oil filled radiator at 5:15 pm as it has to heat the heater first, so at 2 kW we are using 0.5 kWh, 1 kWh or 1.5 kWh to pre-heat the room,
We must also look at the hysteresis, with likely the oil filled radiator being the best, so better the hysteresis the less over temperture it need to go, so also the less energy is lost.
So to heat room for 1 hour, likely fan heater is best, and for 8 hours likely oil filled radiator is the best. But for one hour, looking at 80% (fan heater) to 57% for the oil filled radiator. But using 8 hours likely both around the same, but the oil filled radiator makes no sound, but the fan heater does, so as soon as the fan stops one feels cold.
There are so many more examples, like heating DHW using oil boiler or immersion heater, in winter heat from the pipes boiler to cylinder is not wasted, but summer it means AC runs longer, so winter likely oil is cheapest, summer electric is cheapest to run.
Same with tumble drier condensor heat the room, and vented does not, and as to heat pump, can't compare as it takes so long.
Need big Clive to strip one down.