Voltage optimiser for home use

cfw1994

I've read a few posts on this (eg this one & this one), but they are fairly old posts.
I do firmly believe it is a waste of time & money in our home environment...but felt I'd run it up the flagpole anyway:

We had a company who replaced our solar panel inverters come out to check all is well: in particular, to "check the voltage is right".
Plugged this device into a socket:

Declared our voltage, at 262V, one of the highest they've seen: they would recommend a voltage optimiser, & it could save between 10-19% on electricity costs.  

Sounded vaguely scammy, especially when the cost for said optimiser was £2k +VAT.
A bit more reading suggests it may not be entirely a scam, but in reality it might save us up to 10%....
We have an EV which uses around half our electricity over a year....but since P=VI (unless something fundamental changed whilst I wasn't looking), then it would (I believe) just need charging for longer to get the same energy in: no savings there. 
The rest of the house includes some devices that might just take longer to heat up (or cool down: fridge)....so my calculations suggest we could save around £50-80 pa.
The device only has a 5-year warranty, so a definite "no" from me.

Anyone actually deployed one in a domestic setting?

Is there an argument to ask our *supplier* why we have such a high voltage?!

razord

262V is high for sure. The UK voltage system is supposed to work at 240v -10%, +6%. (216.2 V – 253.0 V)

To be honest, you could test this yourself with a cheap device on amazon, and it's outside those bounds you could ask your power distributor why (not your supplier though - they won't have a clue)

You definitely don't need any device in your house... and I question any promise of savings even if it is as high as they test. Surely a higher voltage means things will actually just happen faster too, not slower? Heat up faster, cool down quicker... The risk is about damaging the devices, not costing you more.

I log all my power consumption data, so here's the last 30 days of supply voltage for various points around my house in case you're interested.

[Deleted User]

If your voltage is 262volts then you need to contact your DNO. The maximum limit for the Grid is 253volts. If you have a smart meter then you can use it to check your Grid voltage. It is worth checking the voltage at night when there is no solar output before contacting your DNO just to make sure that the high voltage is not coming from your inverter. 

https://www.spenergynetworks.co.uk/pages/voltage_changes.aspx

Reed_Richards

Isn't mains voltage 230 V these days, or have we reverted to 240 V since Brexit?

razord

Reed_Richards said:

Isn't mains voltage 230 V these days, or have we reverted to 240 V since Brexit?

EU harmonised on 230v -10% +6%, so we've always been technically fine at 240v. Though we do push that +6% a little.

Verdigris

All the social housing in my fairly small village has solar PV. On sunny summer days the voltage often goes up to 253V, with lots of production and little demand. Never seen it go over, though.

I'm wondering if that is a localised voltage caused by the inverter settings. An ethical installer would adjust the inverter settings, for free, rather than scam you out of £2k for an unnecessary device that costs less than half of that.

Reed_Richards

So you are saying that nothing was changed to alter the actual supply voltage?  

coffeehound

Reed_Richards said:

So you are saying that nothing was changed to alter the actual supply voltage?  

Correct, it was just a paperwork exercise.

My Maplin plug-in registered 265 volts when in the south-west at breakfast time once.  I wonder if it was because there are quite a few power stations down that way.

matelodave

Reed_Richards said:

So you are saying that nothing was changed to alter the actual supply voltage?  

Yes that's correct - the voltage in the UK was never changed, just the specs were tweaked to cover the average over Europe which is only 220 in some places and was up to around 250 in the UK.

As Razord says, 230 -10% to +6% so anywhere between 207 and around 244v would be within spec.

My energy monitor often shows up to 249 volts with the occaisonal excursion above 250.

coffeehound

-6% and +10%

QrizB

cfw1994 said:

I've read a few posts on this (eg this one & this one), but they are fairly old posts.
I do firmly believe it is a waste of time & money in our home environment...but felt I'd run it up the flagpole anyway:

We had a company who replaced our solar panel inverters come out to check all is well: in particular, to "check the voltage is right".
Plugged this device into a socket:

Declared our voltage, at 262V, one of the highest they've seen: they would recommend a voltage optimiser, & it could save between 10-19% on electricity costs.  

Sounded vaguely scammy, especially when the cost for said optimiser was £2k +VAT.

Domestic voltage optimizers are *all* scams. I suggest you do not invite this company's representatives into your house again.

If your domestic voltage is really 262V your inverter will cut out, it's in the specs (para 10.1.3 in this doc). However I don't see a calibration sticker anywhere on that device which makes me think it's mostly designed to scare householders into spending money.

Does your inverter report the mains voltage? What does it say?